Climate change: A virtual special issue with commentary for #COP21

Current Opinion in Environmental Sustainability provides free access to 29 articles on climate change

With sea level rising, low-altitude cities like Venice, Italy, are threatened by more frequent floods. (Photo by Lan Song)

Lan song, PhDTo support the efforts of the UN Conference on Climate Change 2015 (COP 21) in Paris, the Editors-in-Chief of Current Opinion in Environmental Sustainability (COSUST) have organized a Virtual Special Issue focusing on climate change.

Under the headings below, you will find their editorial, presenting the purpose of this special issue and current thinking about climate change and the challenges and opportunities for societal response.

The editors have selected a series of 29 articles that represent relevant themes in climate change research and policy. For each article, authors comment on recent developments related to their topic. All selected articles are freely available for six months until the middle of June 2016.

Lan Song, PhD, Managing Editor, Environmental Science and Health, Elsevier

Contents of virtual special issue

Editorial by Editors-in-Chief

Commentary and links to articles

Editorial by Editors-in-Chief

By Eduardo S Brondizio, William Solecki and Rik Leemans

A melting glacier in Iceland (Photo by Gilles Jonker, Elsevier)On the eve of the Conference of the Parties in Paris (COP21), COSUST is privileged to publish a virtual special issue dedicated to climate change. This issue presents a collection of 27 influential review articles published by our journal during the last six years – and as such represents some of the best thinking on climate change developed since COP15 in Copenhagen in 2009. From reviewing basic research on the climate system and social processes to regional analyses and policy evaluations, the short pape

rs in this issue provide a sobering reflection of the advances and setbacks in research, and on societal and policy responses to climate change. Many of the sources published here have been influential in recent IPCC assessments and in climate change research and action more broadly. The updated reflections provided by the authors on the implications of their works to the COP21 provide for a truly encompassing agenda of relevant issues to be discussed in Paris in coming weeks. Together, we believe, these articles offer a window into current climate change research, debates, and policy for those deeply involved in the field and for those seeking to understand and take-stock on a range of climate change debates.

This diverse collection should be of interest to multiply sets of audiences engaged in the climate negotiations and side-event discussions. The reader will have a chance to review opportunities and challenges for climate change mitigation and adaptation in transforming rural ecosystems and accelerating urban expansion in different parts of the world. Several articles discuss advances and evaluate frameworks for understanding of health implications of climate change, from the impact of biomass burning and waterborne diseases to urban air pollution and heat waves. Comprehensive reviews are provided on the impact of the twin forces of climate change and anthropogenic land use on ecosystems and biodiversity, including reflections on their implications for ecosystem services more broadly. Energy issues are approached from several angles including opportunities and limitations of energy technologies in urban areas, bioenergy trade-offs, and consumption inequalities.

Reflections on the advances of earth systems science is presented from various perspectives, ranging from basic research in key greenhouse gas emissions and nutrient cycling (carbon, methane, nitrogen, and phosphorus) to advances and limitations in modeling tools to coupling marine and land systems processes. In most cases, these discussions are reflected in terms of governance challenges and opportunities. Articles raise questions about climate change mitigation financing mechanisms, such as REDD+, and the need to consider social and ecological outcomes of such programs. Authors call for better articulation of mitigation mechanisms, and the need for expanding the focus of climate change thinking and mitigation programs beyond carbon storage.

A recurrent theme across several articles relates to the persistent fragmentation of mitigation responses and governance mechanisms. Beyond international science-policy interfaces, the role of regional and local decision-makers is increasing significantly in climate change adaptation and mitigation. Articles provide examples of the increasing role of local level efforts acting on landscapes and ecosystems where climate change impacts such as drought, fire, soil fertility, and disease are most felt. It is clear that climate mitigation and adaptation policies continue to be disjointed within and across nations, and such lack of coherence limits the successes of local, regional, and international initiatives. In this sense, directly or indirectly, articles call for expanding deliberative processes and more inclusive science-policy interfaces to evaluate climate change scenarios, policies alternatives under uncertainty, and context-based solutions that speak to regional and local concerns and goals. The recognition that climate adaptation strategies will need to be developed and implemented, and closely linked with mitigation actions also are reflected in the collective voice of the issue authors.

Together, these articles contribute to a comprehensive and critical overview of conceptual, analytical, scientific and policy frameworks underlying current thinking about climate change and the opportunities and challenges for societal responses. These issues have become ever more important as one considers the centrality of climate change governance to the newly approved Sustainable Development Goals (SDGs).

The Editors

Eduardo S. Brondizio, PhDEduardo S. Brondizio is Professor of Anthropology, Indiana University Bloomington, co-director of the Center for the Analysis of Social-Ecological Landscapes (CASEL) and member of the Advisory Council of the Ostrom Workshop in Political Theory and Policy Analysis. Brondizio maintains an active longitudinal research program examining the transformation of society and landscapes of the Amazon, particularly from the perspective of rural populations and their interactions with regional development, urban centers, global markets, and climate change. Brondizio has been closely engaged with international global changed research programs since the mid-1990s and has contributed to several past and on-going global assessments. Brondizio is a member of the inaugural Science Committee of Future Earth and the Science Committee of International Geosphere-Biosphere Programme (IGBP), and Editor-in-Chief of Current Opinions in Environmental Sustainability.

William Solecki, PhDWilliam Solecki’s research focuses on urban environmental change, resilience, and climate adaptation. He has served as the co-leader of several climate impacts studies, most recently as the co-Chair of the New York City Panel on Climate Change and co-PI of the Climate Change Risk in the Urban Northeast Project. He was a lead author of the IPCC, Working Group 2, Urban Areas chapter (chapter 8) and co-coordinating lead author of the US National Climate Assessment, Urbanization, Infrastructure, and Vulnerability chapter (chapter 11). He holds degrees in Geography from Columbia University (BA) and Rutgers University (MA, PhD). He is a Professor in the Department of Geography, Hunter College and a Faculty member of the Earth and Environmental Sciences Program, City University of New York.

Rik Leemans, PhDRik Leemans heads the Environmental Systems Analysis group at Wageningen University. He leads several global-change research projects and contributes to the science-policy assessments of IPCC and the Millennium Ecosystem Assessment. Over the last decades he was active in IGBP, the International Human dimension Programme (IHDP) and DIVERSITAS. He chaired the Earth System Science Partnership (ESSP) and was instrumental to structure the new sustainability programmer Future Earth.

He obtained a MSc in biology from the Radboud University of Nijmegen (Netherlands) and a PhD in plant ecology from Uppsala University (Sweden). Here, he reconstructed and modelled the dynamics of primeval boreal forests. He developed global environmental databases and vegetation models at IIASA (Austria). He led the development of an integrated earth system model, IMAGE, at the Dutch Environmental Assessment Agency. He now develops transdisciplinary approaches to deal with global change and sustainability issues. Prof. Leemans has published papers on ecosystem dynamics, ecosystem services, biodiversity, climate & global change, vulnerability and sustainability, and is Editor-in-Chief of Current Opinion in Environmental Sustainability.

Commentary on In pursuit of carbon accountability: the politics of REDD+ measuring, reporting and verification systems

Aarti Gupta, Esther Turnhout (@EstherTurnhout) and Marjanneke J Vijge, Wageningen University, The Netherlands; Eva Lövbrand, Centre for Climate Science and Policy Research, Linköping University, Sweden

Aarti Gupta, PhDOur paper reviewed critical social science analyses of carbon accounting and measuring, reporting and verification (MRV) systems associated with reducing emissions from deforestation, forest degradation and conservation, sustainable use and enhancement of forest carbon stocks (REDD+). We focused on the politics of negotiating the scope and practices of these systems. In doing so, we advanced the concept of ‘carbon accountability’ to denote and explore a dual meaning of the term: both how forest carbon is accounted for in REDD+ and the need to hold to account those who are doing so.

Marjanneke J Vijge, PhD candidateEva Lövbrand, PhDOur arguments about the politics of REDD+ accounting and accountability remain very pertinent in the lead-up to COP21 in Paris. While the official ‘rule-book’ on critical elements of REDD+ implementation and its MRV systems was finalized by late 2013 within the UNFCCC, crucial political challenges remain. A first pertinent challenge is whether REDD+ activities will be financed through a fund-based or a market-mechanism. The role that market mechanisms will play in a new agreement remains a contested and crucial element of the COP21 negotiations. A key outstanding question is whether and how REDD+ will be included in potential market and/or offsetting arrangements in the new agreement. Such decisions have key practical implications for the stringency and scope of REDD+ MRV systems, including whether such systems promote a ‘carbonization of forests’, or else serve to support various ecosystem functions; and whether and how technical experts and/or local communities are empowered through a future institutionalization of such systems. With regard to a potential carbonization risk associated with an ever-growing focus on MRV systems in REDD+, key questions remain on how socio-economic and biodiversity co-benefits are addressed by these systems, how such knowledge generation is connected to carbon-based accounting, and who is involved with these carbon and non-carbon accounting processes.

A second crucial issue to be determined by COP21 and beyond is how the land sector is to be included in a new agreement, the extent to which a separate accounting regime is specified and whether REDD+ will be part of a separate land use accounting regime. Developing countries have noted with concern that REDD+ MRV rules are more stringent than the Land use, Land use Change and Forests (LULUCF) accounting rules currently applied to developed country emission reduction obligations. Whether and how the existing LULUCF accounting rules will be included in the new agreement, how these rules will be linked to REDD+ MRV systems, and with what political and practical consequences, are key outstanding questions in the lead up to COP21 and beyond. In assessing the political implications of these choices to come, the notion of carbon accountability, as advanced in our paper, remains more current than ever.

Commentary on The Role of Nitrogen in Climate Change

Carolien Kroeze, Environmental Systems Analysis Group, Wageningen University

Nitrogen compounds affect global climate in different ways. Enhanced emissions of the greenhouse gas nitrous oxide (N2O) from terrestrial and aquatic systems is a major contributor to radiative forcing. Increased concentrations of nitrogen oxides (NOx) contribute to the formation of tropospheric ozone (O3) levels, which is another potent greenhouse gas. On the other hand, increased nitrogen availability in the natural environment may result in carbon sequestration, which is a potentially cooling effect. These, and other interactions, have been discussed at the non-CO2 Greenhouse Gas Conferences in Amsterdam in 2011 and 2014(1, 2).

An important conclusion from both conferences is that a large potential exists to reduce emissions of non-CO2 greenhouse gases at relatively low costs. An important strategy to reduce N-related environmental problems is by a more efficient use of N fertilizers. This increases the nutrient use efficiency of crop production. But also changes in the human diets affect emissions of greenhouse gases. In many world regions there is a potential to save N fertilizers without yield loss.

Many other strategies to reduce emissions of N compounds exist. However, end-of-pipe measures for one pollutant often have implications for other pollutants. Integration of models at an animal, crop and farm level with a consequential life cycle sustainability assessment may gain insight in the net effects of climate policies for animal production.

Overall, these conferences conclude that we should not ignore non-CO2 greenhouse gases in climate policies, but also that the relations between greenhouse gases, the N-cycle and the global climate are very complex. Many suggestions for future research are included. These suggestions could guide future research programs aiming at innovations for a sustainable future.


(1) Kroeze C & Bouwman L. The role of nitrogen in climate change. 2011.

(2) Kroeze C et al. Editorial overview: N-related greenhouse gases: Innovations for a sustainable future. 2014.

Commentary on More than CO2: A broader paradigm for managing climate change and variability to avoid ecosystem collapse

McAlpine CA, Ryan JG, Seabrook L, The University of Queensland, School of Geography, Australia; Thomas S, Dargusch PJ, The University of Queensland, School of Integrative Systems, Australia; Syktus JI, Queensland Department of Environment and Resource Management, Australia; Pielke RA Sr, Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, USA; Etter AE, Departamento de Ecología y Territorio, Universidad Javeriana, Bogotá, Colombia; Fearnside PM National Institute for Research in the Amazon (INPA), Amazonas, Brazil; Laurance WF School of Marine and Tropical Biology, James Cook University, Australia

Interconnections between deforestation and climate change represent a major global challenge for the forthcoming COP 21/CMP 11 - United Nations Climate Change Conference in Paris. Deforestation continues at an alarming rate. Globally, from 2000-2010, 13 million ha of forests and woodlands were converted annually to agriculture, biofuels, mining and urban land uses, or lost due to other causes such as fires and drought. Recent estimates indicate 62% increase in net deforestation in the humid tropics from the 1990s to the 2000s (1). Deforestation rates are not uniform, with tropical and subtropical regions presenting the highest absolute and proportional losses, respectively. Indonesia and Malaysia have experienced the largest increase in deforestation, including deforestation hotpots such as the island of Borneo.

Since the publication of this article in 2010, climate change intervention strategies involving forests continue to focus on carbon sequestration. Less attention in the scientific and policy-making communities is given to biogeophysical climate services provided by forests (2, 3). This bias extends to the forthcoming COP21. Inadequate attention is given to the biogeophysical effects of deforestation on the energy and water cycle. This is a critically important given the role of forests in helping to stabilize regional climate and weather through ecosystem processes involving water recycling, cloud formation and precipitation dynamics.

International protocols and treaties strategies for climate mitigation have so far failed to acknowledge the biogeophysical benefits of forest protection and restoration (2). The radiative forcing and other climate forcing associated with changes in forest cover are regionally specific and dependent on the surface characteristics and the spatial structure of the landscape. This produces significant spatially heterogeneous climate forcing that have been shown to influence local and regional weather and climate, and may even alter larger scale atmospheric circulation patterns.

Current land use policies follow a “business-as-usual” approach focusing on short to medium term economic returns associated with the conversion of forests and woodlands to crops, pastures and urban settlements. These policies tend to reinforce regional warming and drying trends in tropical and sub-tropical regions. We call for an alternative pathway, which seeks to intensify agriculture on highly productive lands, while restoring native ecosystems on low-productivity marginal lands. Recent research in Australia demonstrates that large-scale ecosystem restoration is an effective strategy for regional climate protection. The restoration of highly disturbed and degraded lands will provide multiple benefits, including carbon sequestration and enhanced biogeophysical climate services.


(1) Kim et al. Accelerated Deforestation in the Humid Tropics from the 1990s to the 2000s. 2015

(2) Mahmood R. Climate-relevant land-use and land-cover change policies. 2015

(3) Mahmood R. Land cover changes and their biogeophysical effects on climate. 2013.

Commentary on Understanding climate adaptation and transformation challenges in African cities

David Simon, Royal Holloway, University of London and Mistra Urban Futures, Chalmers University; Hayley Leck, Grantham Research Institute on Climate Change and the Environment

David Simon, PhDAfrican cities, their leaders and their citizens have much at stake at the upcoming COP21 to the UNFCCC in Paris. The Climate Summit for Local Leaders will focus on empowering cities, governments and their communities to set ambitious targets for reducing emissions and to create and implement resilient and transformative climate agendas. Ongoing urbanisation trends across Africa present new opportunities and challenges in this context and these challenges must receive central attention and understanding if a progressive and just climate agenda is to be mapped out.

Our recent paper (1) represents arguably the first comprehensive ‘state-of-the-art review’ of African climate change adaptation issues and agendas. It drew on case studies literally from Dakar to Mombasa and from Algiers to Cape Town. There is more climate change research on and in African urban areas than often realised but it remains concentrated disproportionately in mega and large core cities with far less attention to secondary/intermediate cities. It is also poorly communicated through mainstream outlets. We highlight four key challenges to implementation of climate change policies and programmes in African cities, all of which require attention at COP21:

  1. The embedded nature of government structures often inhibits change and innovation for effective climate change action;
  2. Given their strategic importance, urban authorities have increasing roles and responsibilities to address climate change yet often have inadequate power and resources;
  3. Urban-peri-urban-rural interconnections increasingly define the dynamics of urban regions. This has major implications for climate policy and planning. However, due to the spatially bounded institutional nature of municipal powers and responsibilities, these interconnections are rarely embedded in the practice of urban local authorities; and
  4. While city champions, who garner support and lobby for change and resources, play key roles in advancing climate agendas, such individuals are often lost through promotion and/or staff turnover.

A sea change in approaches and behaviour by urban planners, managers, political leaders, firms, residents and other stakeholders is urgently required; yet the capacity and tools are not yet well understood and even less adequate for meeting the challenges.


(1) Simon D & Leck H. Understanding climate adaptation and transformation challenges in African cities. 2015.

Commentary on Energy use in buildings in a long-term perspective

Diana Urge-Vorsatz, Ksenia Petrichenko, Centre for Climate Change and Sustainable Energy Policy (3CSEP), Central European University, Budapest, Hungary; Maja Staniec,University of Western Ontario, Department of Civil and Environmental Engineering, 1151 Richmond Street, N6A 5B8 London, Ontario, Canada; Jiyong Eom, Joint Global Change Research Institute, Pacific Northwest National Laboratory, 5825 University Research Court, Suite 3500, College Park, MD 20740, United States

Our 2013 article in COSUST, Energy use in buildings in a long-term perspective has direct relevance to the COP21 negotiation process. The building sector is particularly important for reducing greenhouse gas emissions for several reasons. First, it is among the largest total contributors to emissions (approximately one-quarter of energy-related CO2emissions), second, it has very significant cost-effective potentials for reductions in emissions, and third, these reductions are often associated with major developmental and socio-economic co-benefits, which often exceed the direct benefits substantially. The 2013 paper reviews the literature on our building energy use futures, and quantifies the major opportunities for changing course in building energy use (and thus emissions). While more models have come out since this paper, there is no other source where our building energy future related literature is comprehensively reviewed.

The feasibility of the ambitious pathways outlined in the paper could be underscored by a few recent developments, including the recent success in nearly zero energy building developments worldwide both on a market-basis and as a policy mandate in various communities and pieces of legislation. The paper also pioneered quantifying the so-called lock-in risk in the building sector, demonstrating that as high as 80% of 2005 building energy use, and the related emissions, may be “locked in” even in a pathway with the most ambitious building energy policies. This highlights the urgency of action at the COP21, because the key remedy to avoid or minimise this lock-in is ambitious policy action to capture the major potentials that are in the building sector. Recent literature since the paper was published substantiates the realisation of these pathways is likely to have a more diverse set of co-benefits than alternative types of mitigation actions.

Commentary on Biodiversity, climate change, and ecosystem services

Georgina M Mace, Department of Genetics, Evolution and Environment, University College London, C Gower Street, London WC1E 6BT, UK; Harold A Mooney, Department of Biology, Stanford University, Stanford, USA

Georgina M Mace, PhDReading our paper (1) now, six years after it was published, is sobering. We covered a huge research area involving climate change, biodiversity and ecosystems, as well as the many interactions between them at a range of scales. We commented on processes already affecting biodiversity and ecosystems, largely the effects of land use, overexploitation, pollution and invasive species. We then highlighted the hard-to-predict potential impacts of climate change, which will add a further stressor to already heavily altered ecosystems. These impacts are expected to be mostly deleterious and sometimes severely damaging and irreversible. We also emphasised the extensive gaps in knowledge that make it so difficult to predict what might happen under future climate change. Our recommendations laid out the key research challenges. Sadly, these have not been developed in the bold or integrated manner that we envisioned, but some substantial progress has nevertheless been made. The good news is that significant initiatives and structures have been put in place, and if these continue to be supported then there will be a stronger basis from which to plan for ecosystem service sustainability as climate change proceeds. Anthropogenic climate change is currently proceeding at the highest end of what was envisaged in 2009, reducing one of the sources of uncertainty though certainly increasing the risks.

There have been many scientific developments, impossible to review in a few sentences. Suffice to say here that our expectations that the impacts of climate change would be variable and context-specific, have been borne out. Contemporary, historical and experimental studies are contributing to a much improved understanding of what the most vulnerable species and ecosystems will turn out to be, and therefore a stronger basis for prediction (2). The definition of ecosystem service vulnerability has also substantially matured since 2009, with an emphasis on distinguishing the underpinning functions of ecosystems from the services that are provided to people as a result of their management. This distinction allows for a more quantitative approach to measuring changes in benefits under different ecosystem management options, including trade-offs (3) and a means to guide decisions (4).

Perhaps the most substantial recent developments, and the basis for a step change in both understanding and policy development, have emerged from a suite of international collaborative actions for biodiversity and ecosystems. National governments as Parties to the UN Convention for Biological Diversity (CBD) identified in 2010 the twenty Aichi targets for 2020 which aim to secure the benefits for future generations. These policy commitments are supported by a new intergovernmental science-policy interface for biodiversity and ecosystem services (IPBES) which is already producing thematic, regional and global assessments. Both the CBD and IPBES will benefit significantly from major efforts to integrate biodiversity, ecosystem services and other relevant datasets. Coordinated through GEO BON , these developments include data, indicators and emerging metrics (5).

While progress has been swift, especially in the area of data, many of the challenges we outlined in  2009- remain relevant. Some, including understanding the interactions between climate change and ecosystems, have become more urgent. We now know some of the elevated risks that result from these interactions. But we also have good emerging evidence that ecosystem management has and can provide important resilience to climate change impacts using the so-called ‘nature-based solutions’. Research at the interface of ecosystems, biodiversity and climate change is still a significant challenge.


(1) Mooney H et al. Biodiversity, climate change, and ecosystem services. Current Opinion in Environmental Sustainability. 2009

(2) Dawson TP et al. Beyond Predictions: Biodiversity Conservation in a Changing Climate. Science. 2011.

(3) Howe C et al. Creating win-wins from trade-offs? Ecosystem services for human well-being: A meta-analysis of ecosystem service trade-offs and synergies in the real world. Global Environmental Change. 2014.

(4) Bennett EM et al. Linking biodiversity, ecosystem services, and human well-being: three challenges for designing research for sustainability. Current Opinion in Environmental Sustainability. 2015.

(5) Pereira HMet al. Essential Biodiversity Variables. Science. 2013

Commentary on The global technical potential of bio-energy in 2050 considering sustainability constraints

Helmut Haberl, Director of the Institute of Social Ecology Vienna; Alpen-Adria Universitaet Klagenfurt, Wien, Graz; Schottenfeldgasse 29; 1070 Vienna, Austria

Bioenergy: tread carefully

Helmut Haberl, PhDAchieving a legally binding global agreement for how to mitigate climate change is the central goal of the forthcoming COP 21 meeting in Paris. Bioenergy is likely to be central in that endeavor. The majority of scenarios meeting the 2°C target analyzed in the recent IPCC Fifth Assessment Report (AR5) relies heavily on the implementation of “negative emission” technologies that remove CO2from the atmosphere in the second half of the 21st century. Bioenergy coupled with carbon capture and storage (BECCS) is perhaps the most important of those technologies. BECCS exploits the ability of plants to soak up carbon while they are growing. When they are burned for energy provision, the CO2 is released again – but if that CO2 is captured and stored the atmospheric CO2 level could be lowered, thereby slowing global warming.

Land, however, is finite and central to a plethora of other demands besides climate change mitigation. Three quarters of the planet’s lands are already used more or less intensively by humans, most importantly to grow food and livestock, but also for forestry and housing. Moreover, land ecosystems provide vital services to humans and biodiversity. Energy crops may therefore compete with food or other crops for fertile land, while jeopardizing biodiversity and ecosystem health. Moreover, conversion of land to energy crops could directly or indirectly (by displacing food crops) result in the loss of carbon-rich ecosystems, thereby reducing or even annihilating intended GHG reductions. Hence, sustainable implementation of bioenergy requires stringent policies to avoid such adverse outcomes.

The original article published in 2010 discussed to what extent land-use competition could affect the scale of bioenergy potential in 2050. Its main message was that future bioenergy potentials depend strongly on dietary choices, agricultural technologies (in particular crop yields and livestock feeding efficiencies), energy crop yields, and other factors. Potentials for purpose-grown energy crops were found to be much lower than previously assumed, whereas other options such as the use of residues, biogenic wastes and by-products (‘cascade utilization’ of biomass) were emphasized. The article influenced the assessment of future bioenergy potentials in both the Global Energy Assessment and the IPCC Fifth Assessment Report.

The field has advanced since the publication of the article. Since 2010, we have gained a better understanding of the contribution of socioeconomic and biophysical determinants. These advances have helped to gauge the magnitude of the future global sustainable bioenergy potential. It is now generally recognized that the large-scale implementation of bioenergy – with or without carbon capture and storage – needs careful attention. There is broad agreement that robust policies are needed to counter potentially adverse effects of bioenergy on other land-use systems and recognition that sustainable climate-change mitigation strategies need to consider synergies and integration among food, fibre and bioenergy supply chains.

Further reading

Haberl H. Competition for land: a sociometabolic perspective. Ecological Economics, 2015.

Haberl H et al. Bioenergy: how much can we expect for 2050? Environmental Research Letters, 2013.

Commentary on Adaptation science for agriculture and natural resource management — urgency and theoretical basis

Holger Meinke (@Ag_Matters) School of Land and Food & Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Australia; Centre for Crop Systems Analysis, Wageningen University, Netherlands; Rohan Nelson, School of Land and Food & Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Australia

Holger Meinke, PhDOur study (1) argued that Adaptation science differs from science for adaptation by developing potential responses to climate change without a predefined disciplinary lens. We were motivated by a disconnect between the mainstream, disciplinary-based science and the transdisciplinary science needed to support adaptation. We showed that adaptation is a complex, multi-scale problem that requires mutual responsibility and collective action by diverse actors. Science needs to play an informing role, while contributing to deliberative and participatory decision-making processes that integrate local knowledge into strategic, context appropriate responses. Its conduct is motivated by a deep sense of purpose (improving lives) and humility (a partial contribution to solutions).

Since our paper was published, the UNFCCC has adopted the Cancun Adaptation Framework calling on parties to address adaptation with the same priority as mitigation. This includes the creation of National Adaptation Plans to proactively anticipate and manage future climate change impacts, which provides an institutional mechanism with potential to promote the types of adaptation science we advocated. Disappointingly much of the UNFCCC’s adaptation agenda has been dedicated to fatuous arguments about who is responsible for the loss and damage caused by climate change, when effort should have been directed towards creating institutional paradigms that foster mutual responsibility and collective action.

The science community is equally to blame for this lack of progress. Instead of creating the deliberative and participatory processes necessary to advance adaptation by embedding science into decision-making processes, conferences and journals have repetitively redefined climate change vulnerability and resilience. Very few transdisciplinary methods or institutional models for creating and applying these methods have emerged, and science input to inform policy development and management actions remains haphazard, and lacking recognition and resources.

To advance the adaptation agenda requires investment in new institutional paradigms that bridge society, policy and science. In agriculture and environmental management, the opportunity exists to create new models of science-policy interactions that create and deliberatively experiment with practical responses. An encouraging development since we published our paper is the emergence of Agricultural Innovation Systems and Innovation Platforms (IP). These IPs seek to extend participation beyond farmers to co-develop new knowledge and collectively implement adaptation with stakeholders across value chains (e.g. 2). IPs provide an institutional model for implementing our perpetual adaptation cycle (1) because they have potential to empower relevant actors, enable better performance and provide a means for selecting science that supports adaptation.


(1) Meinke H et al. Adaptation science for agriculture and natural resource management — urgency and theoretical basis. 2009.

(2) Nederlof S et al. Putting heads together. Agricultural innovation platforms in practice. 2011.

Commentary on Soil carbon in the Arctic and the permafrost carbon feedback

J van Huissteden (@kovanhuissteden) and AJ Dolman, Earth and Climate cluster, Faculty of Earth and Life Sciences, VU University, The Netherlands.

J van Huissteden, PhDIn our study (1) we showed that despite several concentrated research efforts, the release of greenhouse gases from thawing permafrost soils continues to be a very uncertain element in the climate system. A recent review (2) suggests that methane (CH4) emissions from permafrost probably will not exceed anthropogenic emissions. Nevertheless such release makes mitigation of anthropogenic greenhouse gas emission an uphill struggle and abrupt surprises cannot be excluded.

Model-based estimates are still the main instrument to estimate the magnitude of the carbon fluxes from thawing permafrost to the atmosphere because of the small number of observation stations, in particular in the vast Eurasian north. Our paper (1) addressed the variability among model-based estimates and the shortcomings of these models, based on our experience in both modelling and monitoring CH4and CO2 fluxes in northern Siberia.

The most significant problem of modelling greenhouse gas fluxes from thawing permafrost lies in the nature of most permafrost thaw features, which are generally too small to be captured in a model grid. These comprise, for instance, small-scale thaw pond development, lakes and erosional features like gully erosion, and thaw slumps. Lakes and thaw ponds liberate carbon in an anaerobic environment, favouring the formation of CH4, while erosion features result mostly in CO2formation and transfer of carbon to fluvial and marine systems. Models do not yet include these sub-grid features, but are restricted to homogeneous surfaces without realistic emission hotspots at, for example, thaw ponds.

Our article (1) also stressed the importance of ecosystem resilience. Permafrost thaw features do not last forever, but is usually followed re-establishment of carbon sequestering ecosystems over time. Permafrost thaw even may enhance vegetation regrowth by liberating nutrients. Examples are erosion scars where brushes or forest regrow. By using a simple conceptual model we demonstrated the need for better knowledge on the characteristic response of ecosystems to disturbance, including an approach to include this in estimates of the permafrost carbon feedback.

This calls for a better quantification of small-scale permafrost thaw processes and the recovery after that, in particular quantifying the time scale on which this ecosystem resilience operates. More researchers with ‘their feet on the ground' are needed to experiment combined with high quality greenhouse gas flux measurements, to properly quantify these effects. Additionally, many smaller scale permafrost thaw features need not be initiated by climate change alone, they also can be initiated by human activities disturbing the protective vegetation cover of permafrost (3). If, next to climate change, human activities in the arctic start to contribute to permafrost thaw on a large scale, the ecosystem resilience that might help mitigating greenhouse gas fluxes from thawing permafrost, is at stake. Therefore the preservation of ecosystem resilience is highly important.


(1) van Huissteden J &Dolman AJ. Soil carbon in the Arctic and the permafrost carbon feedback. 2012.

(2) Schuur EAG et al. Climate change and the permafrost carbon feedback. 2015.

(3) Nauta AL et al. Permafrost collapse after shrub removal shifts tundra ecosystem to a methane source. 2015.

Commentary on Beyond consensus: Reflections from a democratic perspective on the interaction between climate politics and science

Jeroen P. van der Sluijs, University of Bergen, Norway.

Jeroen P. van der Sluijs, PhDScience-policy interface institutions, such as the Intergovernmental Panel on Climate Change (IPCC), play a primary role in the legitimation of climate policies. In our paper (1) we criticised the dominant linear science-policy interface model where facts determine good policies and calculation is seen as key to well-informed good governance. We proposed a deliberative model as a promising complementary approach to interface climate science and policy. This approach is based on openness about uncertainty and ignorance, systematic reflection and argued choice. This remedies the basic weakness of the Linear Model that underexposes scientific and political dissent. The approach can also fruitfully broaden the option space for decision making and enhance societies’ capacity to deal with uncertainties surrounding knowledge production and knowledge use, while managing climate risks.

Based on this study and subsequent research insights, I recommend the UNFCCC COP21 to:

  1. Exercise more openness about scientific uncertainties and dissent. Policymakers then realize a more complete picture of climate science and its limitations. Instead of creating  policies based on artificially reduced uncertainty through assumption-laden chains of model simulations (2) and on the widest scientific consensus interpretation (3), they can design robust and flexible policies. Robust policies are packages of policy measures that are useful regardless of which of the competing scientific interpretations might be right or the direction uncertainties are going. Flexible strategies can be quickly adjusted to advance scientific insights in which lock-in and irrevocability of implemented policy trajectories can be prevented. Such policies are less vulnerable to uncertainty and to the question of whether Science-policy interfaces have identified the problems correctly and faultlessly (3).
  2. Justify climate policies without needing to opt to highly imperfect reductions and normalisations of complexity in imperfect climate and economic models. Alternative epistemologies and governance arrangements are needed, based on escaping normalisation and reductionism, fostering an ethics of care, participation in the process of transformation, extended peer review, embracement of different forms of knowing and development of socially robust policies (3).
  3. The climate debate should be expanded by focussing more on socially attractive sustainable development perspectives. Quantified carbon emission reduction targets, for example, can unintendedly promote investments and activities that can delay the required transition to sustainable energy systems. Further, the growing urgency of resilience-based climate adaptation, highlights and expands the political climate debate.


(1) van der Sluijs JP et al. Beyond consensus: reflections from a democratic perspective on the interaction between climate politics and science.2010.

(2) van der Sluijs JP & Wardekker JA. Critical appraisal of assumptions in chains of model calculations used to project local climate impacts for adaptation decision support—the case of Baakse Beek. 2015.

(3) van der Sluijs JP. Uncertainty and Dissent in Climate Risk Assessment: A Post-Normal Perspective. 2012.

Commentary on Latin American cities and climate change challenges and options to mitigation and adaptation responses

Jorgelina Hardoy IIED−América Latina, Florida; Vicente López, Buenos Aires, Argentina; Patricia Romero Lankao, National Center for Atmospheric Research, USA

Jorgelina Hardoy, PhDPatricia Romero Lankao, PhDIn 2011, we published, “Latin American cities and climate change: challenges and options to mitigation and adaptation responses.” Since that time, we have seen many of our assertions and projections come into reality. Local governmental and nongovernmental actors in urban Latin America are taking mitigation and adaptation actions. This is happening despite the fact that jurisdiction over many dimensions of climate change adaptation and mitigation along with technical and financial capacity resides at the nation-state level. Innovative institutional frameworks and governance mechanisms have been developed throughout Latin America and the Caribbean over the last few years. However, governance challenges persist such as lack of financial resources, centralized administrative structures and top-down transmission of climate relevant information, and siloed, fragmented and uncoordinated structures and responses by city agencies and departments.

These challenges have contributed to a gap between the commitment of Latin American cities to address climate change, and the effectiveness of their responses. Furthermore, these have often led to incremental and piecemeal policies controlled by local jurisdictions or single institutions and private and community actors. Most of the success cases remain as outliers. It has been difficult for most local governments in Latin America to address climate change in an integrated way while promoting local development agendas that enhance adaptive capacity and result in win – win solutions that address both short term development needs and long term climate challenges. More thought and action is needed to promote better forms of governance where private, public and civil society actors engage in integrated development agendas and simultaneously address climate goals.

The UNFCCC COP-related Lima Paris Action Agenda to accelerate the growing engagement and cooperation of governmental and nongovernmental actors, including cities, in climate action, and the NAZCA portal may prove to be appropriate mechanisms. But when looking at the cases included on the website portal, one can find as of late November 2015, 2,235 cities making climate action commitments but only 75 in Latin American and Caribbean region. This offers an idea of the challenges cities face in this part of the world.

Commentary on Governing the health risks of climate change: towards multi-sector responses

Kathryn J. Bowen, National Centre for Epidemiology and Population Health, Australian National University & Melbourne Sustainable Society Institute, University of Melbourne

Kristie L. Ebi, Department of Global Health and Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington

Kathryn J. Bowen, PhDThe health risks of climate change will be one of the most tangible points of debate for countries involved in the COP21 negotiations in Paris. These health risks result from the effects of increasing climate variability through droughts, storms, floods and other weather events, and the effects of long-term changes in weather patterns through changes in the geographic range of malaria, dengue, and other diseases (1) The World Health Organization (2)  concluded that climate change is expected to cause an additional 250,000 deaths per year between 2030 and 2050. These deaths will be the result of major killer of children: undernutrition, malaria and diarrhoea; and heat exposure in the elderly. Articulating this connection and humanising the impacts will go a long way to persuade those in positions of power that it is absolutely fundamental to achieve strong and binding emissions targets in COP21. Strengthening mitigation and adaptation activities will reduce the threats to health, but this also requires effective collaboration with other sectors, such as water, agriculture and disaster management.

The COP21 negotiations can further strengthen cross-cutting approaches to managing risks. The Sustainable Development Goals, adopted in October this year, go some way in emphasising the importance of working beyond organisational silos. For example, the second goal “End hunger, achieve food security and improved nutrition, and promote sustainable agriculture” cannot be achieved without genuine and effective partnerships between the agriculture, health, water and rural development sectors, and across public and private organisations. Health must be at the forefront of these discussions for a humane response to our changing climate.


(1) Bowen KJ & Ebi KL. Governing the health risks of climate change: towards multi-sector responses. 2015.

(2) Hales S, Kovats S, Lloyd S, Campbell-Lendrum D. Quantitative risk assessment of the effects of climate change on selected causes of death, 2030s and 2050s. 2014.

Commentary on An imperative for climate change planning: tracking Earth's global energy

Kevin E Trenberth, National Center for Atmospheric Research, Boulder, CO, USA

Earth’s energy imbalance as a key indicator of climate change

The current Earth’s Energy Imbalance (EEI) is mostly the result of human activities and is driving global warming. The absolute value of EEI arguably represents the most fundamental metric defining the status of global climate change. As described in my original article (1), EEI is difficult to measure accurately, because large monthly variations are associated with clouds and weather systems that create a form of noise. However, such measurements will be more useful than global surface temperature in understanding climate change.

Kevin-E-TrenberthEEI can best be estimated by taking an inventory of where the extra heat is going, and of course that has consequences. Most (>90%) heat goes into Ocean Heat Content changes, which can now be measured more accurately using sustained observations from the Argo array of autonomous profiling floats. Radiation measurements from space provide very useful complementary direct measurements of changes, but lack absolute accuracy. Other components, such as melting land and sea ice, and warming of the ground and the atmosphere, can also be included. Improving observations and analysis of these climate system components and how they are blended together is an active research topic. The prospects are thus great for much better information that has direct implications for future change.

While it is essential to make progress on ‘mitigation’ – reducing emissions of heat trapping gases – and also ‘adaptation’ which means building resilience and planning for the consequences as best we can, we also need a ‘climate information system’ that tells us what to plan to adapt to on various time scales. Tracking EEI will be an essential part of this information system.

The events of 2015 are an excellent example, as a strong El Niño has developed, redistributing heat that had built up in the ocean as a result of EEI. Warm waters spread across the Pacific so that sea surface temperatures have been at record high levels, with consequences for the most active hurricane/typhoon year on record for Category 4 and 5 storms that cause the most damage. Regional droughts, heat waves and wildfires in some regions accompany major flooding events elsewhere, and highlight the importance of the climate change, mixed with climate variability, and the need to better track Earth’s global energy.


(1) Trenberth KE. An imperative for climate change planning: tracking Earth's global energy. 2009.

Commentary on Limits to adaptation to climate change: a risk approach

Kirstin Dow, Department of Geography, University of South Carolina

Frans Berkhout, Department of Geography, King’s College, London

The Paris COP discussions will include reporting on the first year of the interim workplan of the Warsaw International Mechanism for Loss and Damage, and debate over where the topic of ‘loss and damage’ should appear within the UNFCCC’s structure. The issue of loss and damage is a long-standing controversy with the debate bogged-down over countries’ rights and responsibilities on one hand and their compensation and restoration on the other. These discussions beg the difficult questions about attribution to climate change, as well as complex legal and political questions about potential liability of rich countries for the losses associated with their historical emissions. While these discussions should continue, the near-term prospects for substantial progress on these topics in UNFCCC’s context are limited. Efforts and attention should be directed to the real and deepening problem that people around the world are being affected by climate change and face losses and damages as a result.

We see a more actor-centered and sustainable development framing of the problem of loss and damage as more scientifically robust, while also creating a context for a politically-achievable international response to the urgent and growing problem of climate-related crises around the world – in richer and poorer countries. We believe that a risk-based approach to understanding the limits to the capacity of groups, sectors and regions to adapt to the impacts of climate change – in the context of other social, economic and political factors shaping their vulnerability – offers a path forward to address immediate and future needs. In the associated paper (1), we address the initial challenge of developing a workable definition of limits to adaptation and explore the governance implications of approaching and exceeding adaptation limits, and the risks of associated losses and damages.

As the discussion of adaptation limits further develops, it raises at least two broad research and policy questions related to loss and damages. What types of international risk governance and management activities are needed to anticipate and, where possible, avoid adaption limits? We can anticipate that, as the impacts of climate change become more persistent, the investments in adaptation needed to secure sustainable development will grow. International economic policies need to be reshaped to take account of these new and growing dimensions of risk and investments in adaptation. The aim will be to continue to meet development objectives while building the climate resilience of communities, sectors and countries. Where adaptation limits cannot be avoided, how can they be best negotiated in ways that minimize losses and support the rapid recovery of damages? What types of prediction, planning, and management efforts can realize opportunities in the major and discontinuous changes to livelihoods and well-being?  We believe that there is a need to think afresh about international arrangements to respond to development needs in extremis, where the scope for disaster risk reduction has narrowed, including the appeal to international legal principles, such as the responsibility to protect.


(1) Dow K et al: Limits to adaptation to climate change: a risk approach. 2013.

Commentary on ‘Tipping points’ for the Amazon Forests

Nobre CA, CAPES, Brazilian Ministry of Education, Brazil

Borma LS, INPE, Brazil

The study (1) summarizes a period in which the understanding emerged that the potential occurrence of synergistic effects among major anthropogenic drivers of change of tropical forests in the Amazon —namely climate change, drought extremes, deforestation and fire — could lead to a tipping point of biome change: the current species-rich and abundant tropical forest would shift into a dry and species-poor vegetation, similar to an impoverished savanna. Between 2009 and 2015, although there have been changes in trends of these drivers, the future outlook of the Amazon forest does not seem to have softened:

  1. Deforestation: Amazonian annual deforestation rates decreased after 2005, from a loss of almost 28*103 km2 in 2004 to a minimum of 4.5*103 km2 in 2012. Although a slight increase was recorded, rates remained low in 2013 and 2014;
  2. Extreme events and climate variability: Interspersed with dry extremes observed in 2005 and 2010 in the region, extreme floods were recorded in 2009, 2012 and 2013. 2015 has been set as another El Niño extreme drought. Interannual variability is a recognized pattern of the Amazon climate, but the increase in frequency and intensity of extreme events could be configured as a manifestation of a more gradual climate change. Still, despite the occurrence of flood events, several studies have pointed to an increase of the dry season period in southern Amazon (2), which could be a possible sign of an approaching systemic tipping towards impoverished savannas (3);
  3. Fires: Amazonian forest fires exhibit strong synergy with deforestation and droughts. Recent experimental observations in the transition forests of the southern Amazon confirms that forest fire increases the likelihood of savannization (4). Decrease in deforestation rates associated with observed reduction of extremes droughts have decreased forest fires occurrence in the region, particularly during extreme floods. However, it should be mentioned that this can be a circumstantial condition and not necessarily a change in local farming behavior and practices, which, despite all the risks, still relies greatly on forest fires; and
  4. Climate change: From four drivers considered, this seems to be the one which presented the least relief, as the average temperature of the planet continues to rise due to the increase in GHGs emissions. Despite the potential effects of CO2 fertilization for forest growth, decrease in carbon accumulation rates has been observed in the Amazon region. Climate risk assessments show that the current mitigation pledges under UNFCCC before COP21 in Paris would result in a 2.7oC global warming, about 3o C in Tropical South America, close to the tipping point of 3.5-4oC for the Amazon. In conclusion, it increasingly appears that, even if deforestaton rates are brought down to near zero, climate change still presents a major and growing threat to the Amazon.


(1) Nobre CA & Borma, LS. ‘Tipping points’ for the Amazon forest. 2009.

(2) Fu R et al. Incresed dry-season length over southern Amazonia in recent decades and its implication for future climate projection. 2013.

(3) Settele J et al. Terrestrial and inland water systems. 2014

(4) Balch JK et al. The Susceptibility of Southeastern Amazon Forests to Fire: Insights from a Large-Scale Burn Experiment. 2015.

Commentary on Modelling the potential impacts of climate change and human activities on the sustainability of marine resources

Manuel Barange, PhD  Manuel Barange (@Manu_pml), Plymouth Marine Laboratory, UK

In 1986, Francis P. Bretherton developed what has been called the ‘Bretherton Diagram’ (1) when describing the principles behind Earth System Science. The diagram reflected the need for a Science that is focused on the interactions between physical, biological and human systems instead of the systems themselves. More recently, emerging research programs as Future Earth, the new global program for sustainability research, use Bretherton’s principles to define a research agenda that considers the ways in which human systems and social processes interact, and how they affect environmental systems and processes  worldwide  (2). The point of Bretherton, and of Earth System Science, is that when one system acts another reacts, in less than trivial ways. Because outputs from one system become inputs to another, none of these can be evaluated in isolation. And yet, we are still trying to find tools and mechanisms to apply this interdisciplinary approach to global environmental change research. Our paper (3) set the scene to explain why this approach is essential in (but not exclusive to) marine global environmental research. We made the case that without incorporating human activity in our projections we forget that human activity has the capacity to amplify and minimise climate change impacts. We called for models exploring the synergistic dual exposure of marine ecosystems to climate change and human activity to provide meaningful and realistic projections of change leading to effective adaptation and mitigation strategies. Recent work (4, 5) has used the same framework to investigate scale-dependent interactions between human and natural systems globally, regionally and nationally. The relevance of this approach for the COP21 summit in Paris is the growing recognition that coupled modelling frameworks are the only tools that would allow society to investigate the trade-offs between adaptation and mitigation measures, minimizing impacts and maximizing benefits. Failure to use these approaches may lead to unexpected rather than planned outcomes. More surprises is the last thing that the COP process needs.


(1) Earth System Science Committee, NASA Advisory Council (F. Bretherton Chair). Earth system science: a closer view. Washington DC: National Aeronautics and Space Administration (NASA). 1988.

(2) Mooney HA et al. Evolution of natural and social science interactions in global change research programs. 2013.

(3) Barange M et al. Modelling the potential impacts of climate change and human activities on the sustainability of marine resources. 2010.

(4) Barange M et al. Impacts of climate change on marine ecosystem production in societies dependent on fisheries. 2014.

(5) Mullon C M et al. Quantitative pathways for Northeast Atlantic fisheries based on climate, ecological–economic and governance modelling scenarios. 2016.

Commentary on Gender impacts and determinants of energy poverty: are we asking the right questions?

Shonali Pachaurii & Narasimha D Rao, Energy Program, International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria

Shonali Pachauri, PhDSince the publication of this paper in 2013, issues of energy access and equity, including gender equity, have gained increased attention with the approval of the UN Sustainable Development Goals (SDGs). A unique feature of the SDGs is the explicit recognition of universal modern energy access as a development goal. Energy, however, underlines several, if not most of the SDGs. The findings of our initial review on the gender differentiated impacts and determinants of energy poverty still stand. The social impacts of energy deprivation and the role of women in overcoming energy deprivation are still less understood in the energy literature than the economic and environmental dimensions of energy. Our paper highlights, for instance, that domestic decisions such as around the purchase and use of modern cook stoves and electric appliances influence both the uptake of modern energy and the extent to which women actually benefit from this transition. These decisions involve intra-household gender relations, bargaining power, and other cultural issues that fall outside the domain of traditional energy analysis. These micro-level dimensions, however, are increasingly important in the context of expanding government programs and subsidies to improve access to energy, and cash transfer programs more broadly to low-income households.

Narasimha D Rao, PhDInterdisciplinary research that focuses on gender aspects of household energy use is needed to design effective policy mechanisms to facilitate energy transitions, as well as to understand the impacts of climate change on energy use and vice versa. One of the efforts in this direction, for instance, is the gender and energy research program being coordinated by the International Network on Gender and Sustainable Energy (ENERGIA). Funded by the UK’s Department for International Development (DFID), this research aims at advancing knowledge and awareness regarding the impact of energy access—or the lack thereof—on women and girls. More research effort and empirical evidence are needed to understand the factors – both outside and within the household – that influence women’s decision-making power in relation to the adoption of modern energy services, and whether their adoption leads to the intended benefits to women and their families.

Commentary on Health co-benefits of climate mitigation in urban areas

Patrick L Kinney, Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA

In this 2010 Current Opinion paper, we argued that short-term, local benefits of climate mitigation policies (“co-benefits”) should inform climate mitigation strategies, but that the research effort necessary to quantify these co-benefits had not been optimized for policy impact. Specifically, we concluded that as a whole the literature was too focused on developed countries, too focused on air pollution, and prone to build on policy scenarios that were of limited relevance to policy makers. In spite of these concerns, we believed then – and we believe even more firmly now – that the evidence is sufficient to conclude that health co-benefits are large in magnitude, and must be considered as governments convene in Paris to assess the net benefits of climate mitigation.

In the five years that have elapsed since we surveyed the literature, dozens of additional high quality co-benefits studies have been published. We highlight two contributions that epitomize the approaches that we called for. Driscoll et al. (1) show electricity sector policies can generate both greenhouse gas and air pollution benefits, but that the magnitude of the co-benefit is sensitive to the policy instrument selected. Their analysis illustrates how an interdisciplinary team can generate insights that are both highly policy relevant – thanks to their policy model’s fidelity to the United States’ Clean Power Plan – and scientifically credible. Reddington et al. (2) look retrospectively at the air-pollution related health co-benefits from reductions in agricultural biomass burning in the Brazilian Amazon over a 11-year period beginning in 2001. Their work shows how retrospective studies can both validate past policy decisions and can pave the way for strong climate mitigation policies in the future.


(1) Driscoll CT et al. US power plant carbon standards and clean air and health co-benefits. 2015.

(2) Reddington CL et al. Air quality and human health improvements from reductions in deforestation-related fire in Brazil.2015.

Commentary on Carbon-climate feedbacks a review of model and observation based estimates

Pierre Friedlingstein, University of Exeter, UK.

Our study (1) showed that climate and carbon cycle are tightly coupled from interannual to multi-millennial timescales. Observations always evidence a positive feedback, warming leading to release of carbon to the atmosphere; however, the processes at play differ depending on the timescales. State-of-the-art Earth System Models (ESMs) now represent these climate-carbon cycle feedbacks and also always simulate a positive feedback over the 20th and 21stcenturies, although with substantial uncertainty; the climate carbon cycle feedback could accelerate the build up of atmospheric CO2 in the atmosphere and hence the 21st century warming by up to one degree C for unmitigated scenarios, such as RCP8.5.

Recent studies, based on observations now can help reducing this uncertainty. On short, inter-annual timescales, El Niño years record larger than average atmospheric CO2 growth rate, with tropical land ecosystems being the main drivers of these anomalies. These climate-carbon cycle excursions during El Niño can be used as an emerging constraint on the tropical land carbon response to future climate change. On longer, centennial time-scales, the slow variability of both atmospheric CO2 as recorded in ice cores and surface temperature as deduced from environmental proxies, have be used to constrain the overall global carbon cycle response to warmer or colder climate periods (such as the little ice age in the early part of the 17th century). Each of these independent, observations based methods point to climate-carbon cycle feedback at the low-end of the Earth System Models’ range. This indicates that these models overestimate the carbon cycle sensitivity to climate change.

In the context of cumulative CO2emissions and the two degree C climate target, this should be seen as reassuring news. A low climate-carbon cycle feedback means that larger cumulative CO2emissions are compatible with a given climate target. The best estimate from IPCC AR5 was a cumulative emission of 790 GtC is likely to limit global surface warming to less than two degree C relative to pre-industrial. Humanity already emitted about 535 GtC up to now, only leaving about 255 GtC for the future. This is about 25 years of current emissions. However this likely estimate comes from an assessment of ESMs including models with large climate-carbon cycle feedbacks. Not including them would in the assessment would slightly increase the cumulative budget and hence the remaining emissions compatible with the 2°C target.


(1) Friedlingstein P and Prentice IC. Carbon-climate feedbacks: a review of model and observation based estimates. 2010.

Commentary on Carbon emissions and the drivers of deforestation and forest degradation in the tropics

Richard A Houghton, Woods Hole Research Center, Falmouth, MA, USA

Richard A Houghton, PhDMy 2012 study (1) is relevant to COP-21 for at least two reasons. First, the article provides estimates of the carbon emissions from tropical deforestation and forest degradation, and thereby informs the UNFCCC’s Reduced Emissions from Deforestation and forest Degradation (REDD+) programme. The net carbon emissions from deforestation and degradation within tropical countries are estimated to have been 1.4 PgC yr-1 over the period 1990-2010 (about 16% of global carbon emissions). That percentage has declined in the last five years, in part, because rates of deforestation have declined and, in part, because fossil fuel use has continued to rise (2). Deforestation and degradation of tropical forests, including peat forests, contributed about 11% of total carbon emissions in 2013.

This estimate of 1.4 PgC yr-1 represents a net loss of carbon, including both gross emissions of 3-4 PgC yr-1 and an uptake of as much as 3 PgC yr-1 by forests recovering from harvests and agricultural abandonment. My 2012 study (1) attributed much of the emissions and uptake of carbon to shifting cultivation. The practice is not necessarily the traditional practice of shifting cultivation, or swidden, however. Rather, large areas of tropical croplands are abandoned each year because of lost fertility and reduced productivity. These abandoned lands start returning to forest, and are replaced by newly deforested lands. The dynamics appear in data from FAOstat, showing a reduction in forest area that is larger than the reported increase in croplands and pastures. Deforestation to replace worn-out agricultural lands is large and this accounts for a third of tropical deforestation over the period 1990 to 2014.

The second reason why my 2012 study (1) is relevant for COP-21 is its suggestion that tropical forest management could play a role in stabilizing the CO2 concentration of the atmosphere while the world transitions from fossil to renewable fuels. Halting emissions by stopping deforestation and forest degradation, allowing secondary forests to grow (i.e. restricting logging), and establishing forests on large areas of once-forested but not currently used lands could replace the current emissions of 1.4 PgC yr-1 with an annual sink of as much as 4 PgC yr-1. That sink could persist for the three to five decades necessary for an energy transition and, thereby, limit the increase in CO2 concentration while fossil fuels are phased out (3).

Reforestation has long been recognized as a way to remove carbon from the atmosphere, but seems not to be seriously considered, probably because deforestation and forest degradation account for only about 10% of carbon emissions (i.e. carbon on land is small relative to the amount of carbon in fossil fuel reserves). However, this 10% is more likely 50% when gross sources and sinks from forest management are considered and when the potential terrestrial sink is compared with the amount of fossil fuel carbon that can be released if global warming is not to exceed 2oC.


(1) Houghton RA. Carbon emissions and the drivers of deforestation and forest degradation in the tropics. 2012.

(2) Le Quéré C et al. Global carbon budget 2014.2015.

(3) Houghton RA et al. A role for tropical forests in stabilizing atmospheric CO2. 2015.

Commentary on Climate change and Ecosystem-based Adaptation: a new pragmatic approach to buffering climate change impacts

Richard Munang (@RichardMunang) United Nations Environment Programme, Nairobi, Kenya

Thwarting Climate change impacts through harnessing Ecosystem-based Adaptation

Richard Munang, PhDThe impacts of climate change already occur and clearly manifest themselves in the form of, for example, droughts and yield reductions. As this happens millions of people are currently been affected thwarting their efforts to escape poverty. This is especially so in Africa, among the most vulnerable regions with over 50% in extreme poverty, 60% youth unemployment and 25% going hungry to bed. Exacerbating these vulnerabilities, Africa faces a barrage of climate impacts impinging on its economic growth. Adaptation is therefore an urgent imperative for the world’s poorest

The global community at the Rio+20 conference explicitly recognized that healthy ecosystems are the core element of climate adaptation. Ample scientific evidence provides the basis for their protection and sustainable use. In Africa, this imperative is anchored in key strategic documents, including the AMCEN Cairo Declaration, especially Decision 1, the AU Agenda 2063, common African position on RIO+20, the global Agenda 2030 on sustainable development. Implementing these strategies will build climate resilience and dovetail into the Paris deal. However, regardless of how promising these blue-prints are, their achievement requires partnerships to blend strengths of governments, the private sector, non-profits among others as implied in SDG17. To date, gaps in financing, in commercialization, in technology transfer, in techniques etc. have led to the perpetuation of these policies – this action gap has long stymied African development. These glaring gaps are addressed by the Ecosystem Based Adaptation for Food Security Assembly (EBAFOSA) (1).

Formed by UNEP, in collaboration with the African Union Commission and others, EBAFOSA is the first inclusive pan-African policy framework and implementation platform, a solutions space that brings together key stakeholders and actors along the entire EBA driven agriculture value chain, from government & the public sector, private sector, academia & research, NGOs, CSOs, international organizations and individuals at national and continental level to forge partnerships aimed at upscaling ecosystem-based-adaptation driven agriculture and its value chains into policies and implementation. The process is country driven to ensure food security, climate adaptation, enhanced ecosystem productivity and link to both supply and demand side value chains. This will help to create numerous income and job opportunities. By providing a platform for interactions between business to business, business to government, business to research, person to person, government to research etc., EBAFOSA catalyzes synergy to implement actions.

By focusing on building relevant partnerships across local or international solutions providers, and on leveraging healthy ecosystems to achieve food security and sustainable inclusive growth, EBAFOSA is positioned as a platform that could potentially see Africa meaningfully achieve different SDGs. It is hence a crucial vehicle in Africa’s post-2015 and post COP21 journey. In EBAFOSA lies the opportunities which if tapped, can determine whether the 21st century truly belongs to Africa.


(1) Munang R et al. Climate change and Ecosystem-based Adaptation: a new pragmatic approach to buffering climate change impacts. 2013.

Reflection on Climate change and urban resilience

Robin Leichenko, Rutgers University, New Jersey, USA

Since publication of "Climate change and urban resilience" in 2011, enhancement of resiliency has become a dominant approach for climate change adaptation in cities and regions throughout the world. A number of important developments and innovations in the resilience literature have occurred in tandem with the ascendency of this concept. With respect to terminology, there is growing awareness of the need to define resilience to include both the ability to "bounce back" from climate and hazard-related shocks and stresses and the capacity to “bounce forward” (1). This expanded definition of resilience places emphasis on preparedness and anticipation of extreme events, learning from the consequences of past events, and identification of ways to rebuild that reduce vulnerability to future events (2).

Another advancement in resilience research entails efforts to measure and quantify levels of community resilience and to assess the effectiveness of resilience-building efforts. Work in this vein is developing quantitative metrics of resilience that are applicable across locations and identifying common factors that enhance the resiliency of cities and communities (3). A third development in the resilience literature is the growing body of research that explores barriers, limits and limitations to resiliency approaches (4). This work is investigating political, economic, technical, cultural and institutional obstacles to resilience and is specifying both absolute (i.e. system level constraints) and socially-defined limits to the effectiveness of resiliency efforts. Some work in this vein is highly critical of resilience-based approaches, arguing that these strategies do not address underlying inequalities or political and economic drivers of vulnerability and climate change (5). Other studies are finding new opportunities whereby resiliency framings might be used to challenge the status quo and empower local actors and communities to enact transformative change (6) (7).

As this brief commentary suggests, interest in the topic of urban resilience to climate change is growing apace, and understanding of the conceptual underpinnings, metrics, and implications of resilience is continuing to evolve. While widespread acceptance of the need for urban climate resilience is an acknowledgement that adaptation will be necessary in the face of climatic changes that are already "baked into" the system, growing concerns about the limits and limitations of resilience are indicative of the need for significant reductions in emissions in order to avoid future impacts that exceed the resilience capacity of cities, their residents, and the infrastructure systems that help sustain them.


(1) Manyena S et al. Disaster resilience: A bounce back or bounce forward ability? 2011

(2) Leichenko R & Mahecha A. Celebrating Geography's Place in an Inclusive and Collaborative Anthropo(s)cene.2015

(3) Cutter S et al. The geographies of community disaster resilience. 2014

(4) Leichenko R et al. Barriers, Limits, and Limitations to Resilience. 2015

(5) Brown, K . Global environmental change I: A social turn for resilience?2014.

(6) Cretney R & Bond S `Bouncing back' to capitalism? Grass-roots autonomous activism in shaping discourses of resilience and transformation following disaster. 2014

(7) Bahadur A & Tanner T. Transformational resilience thinking: Putting people, power and politics at the heart of urban climate resilience. 2014.

Commentary on Climate Change and Health in Cities: Impacts of Heat and Air Pollution and Potential Co-Benefits from Mitigation and Adaptation

Sharon L Harlan, Northeastern University, USA; Darren Ruddell (@SSI_Prof), The Spatial Sciences Institute at the University of Southern California, USA

Sharon L Harlan, PhDIn the four and a half years since the publication of our review article, “Climate Change and Health in Cities: Impacts of Heat and Air Pollution and Potential Co-Benefits from Mitigation and Adaptation,” studies of extreme heat and air pollution have multiplied rapidly in epidemiology, climate science, and geosciences, showing heightened awareness and concern about the effects of changing urban environments on human health. Improved measurement and models for micro-scale temperatures and air quality, as well as better availability of mortality and morbidity data, now provide an even firmer basis for projecting adverse effects of extreme heat and air pollution on human health. These advances will also allow finer-grained analysis of health disparities in the coming decades.

Emerging trends in heat research suggest that deaths alone account for only a small fraction of all heat-related health impacts; hospitalizations, emergency room visits, and self-reported symptoms account for many more incidents. Chronic exposure to high temperatures in hot climates can be as dangerous to health as episodic heat waves in temperate climate zones. Human acclimatization to the projected rise in global temperature in some locations may not be physiologically possible.

We are gaining a better understanding of the social and technological factors that mediate the relationships between temperature and health risks, although more research is needed. It is estimated that, by mid-century, continued urbanization and population growth, particularly in Asia and Africa, will place another 2.5 billion urban dwellers at risk of diseases related to air pollution. Continuing growth in energy production, combined with rising automobile ownership, has burdened Chinese megacities with some of the poorest air quality in the world. In terms of adaptation strategies, cities are improving warning systems that alert residents to extreme heat and dangerous air quality days, as well as experimenting with more sustainable urban designs for buildings, land use, transportation, and energy conservation programs. However, city-level adaptations should be coupled with national policies addressing not only the effects of climate change, but population growth and consumption demands, energy production, and air pollution. An international agreement committed to a sharp reduction in global emissions at COP21 in Paris will be a strong positive influence on the likelihood of long-term successful local adaptations and mitigation efforts to promote environmental and human health.

Commentary on GHG emissions from urbanization and opportunities for urban carbon mitigation

Shobhakar Dhakal, Energy Field of Study, School of Environment, Resources and Development, Asian Institute of Technology (AIT), Thailand

Here I reflect on my article, “GHG emissions from urbanization and opportunities for urban carbon mitigation” published in COSUST in 2010. The most optimistic outcome from COP-21 is a legally binding ambitious global mitigation target applicable to all parties. However, the submitted intended nationally determined contributions (INDCs) and the ongoing political discourse point towards possibly a voluntary, pledged-based, and periodically-reviewed global system of mitigation governance. Especially for the later outcomes, raising the level of mitigation ambition and effectiveness require well-networked and result-oriented bottom-up initiatives, especially from cities and territories.

The greater realization on importance of cities is observed towards the run-up to the COP-21 deliberations. The role of cities are indeed crucial- the 2010 paper and also recent IPCC report shows that cities contribute 71-75% of global energy related CO2 emission, and if the embodied emissions in consumption are considered, cities’ opportunities for global mitigation would be immense. In this context, the paper and subsequent research searches for answers to two broad questions: what do we know about the GHG emissions from cities and future urbanization and what are the key opportunities to mitigate GHG from cities and their efficient governance?

If we to entrust more role to city decision makers in post-2015 climate regime, the accounting of urban emission and mitigation needs a better framework. The quantification of urban contribution to global, regional and national GHGs and city estimates are limited to few regions, selected cities and for mostly CO2. The GHG emissions and mitigation potentials of urban areas differ widely for the accounting methods, scope, emission sources and urban definition making place-based comparisons and tracking of achievements difficult. Recent IPCC report and other literature have also shown, similar to the paper, that the end-of-pipe solutions and sectoral efforts are necessary but not sufficient, and that systemic and integrated system perspectives are needed in the city actions. While greater role for cities are being emphasized in run-up to COP-21, the evidence of aggregated impacts of city actions on GHG reductions are limited which calls for a better formulation of the city climate change action plans and their effective implementation.

It is also important for COP-21 deliberations and Commentary developments to take a pragmatic look into the system of urban mitigation governance. An efficient urban carbon governance must be ascertained by a careful examination of stakeholders and consideration of who can influence the urban carbon mitigation the most in different urban settings; this means that the role of local government is necessary but not always sufficient for urban carbon governance. Last, but not the least, global mitigation calls for a transformative change but, at the same time, incremental solutions must be accelerated for which multiple co-benefits of climate change mitigation must be assessed in cities including mitigation-adaptation synergies. In summary, the key messages of the paper to COP-21 are to support sound accounting of urban emissions and mitigation potentials, facilitate high impact systemic and integrated mitigation solutions, consider multilevel governance, and smoothen the entry to urban climate mitigation by maximizing co-benefits and other developmental synergies.

Commentary on Carbon-nitrogen interactions on land at global scales: current understanding in modelling climate biosphere feedbacks

Sönke Zaehle and Daniela Dalmonech, Max Planck Institute for Biogeochemistry, Jena, Germany

Sönke Zaehle, PhD.jpgSince 2011, the interactions between the terrestrial nitrogen (N) and carbon (C) cycle have gained more attention in the global Earth system modelling community because of their potential effects on the climate system. Since the publication of our study (1) significant progress has been made in the evaluation of local and global models by utilizing the outcomes of ecosystem manipulation experiments [e.g. 2]. These studies have underlined the capacity of the models to simulate key features of the observed carbon-nitrogen cycle interactions. However, they have also revealed significant model weaknesses and thus uncertainties in the projections of these models, which have spurred subsequent model developments.

New future projections of coupled carbon-nitrogen cycle models are available [e.g. 3,4], which generally support earlier model simulations discussed in our 2011 paper (1). Accounting for the interactions of the C and N cycle leads to a strongly reduces the CO2 fertilization effect on land, attenuated C losses in response to warming and moderate increases of land carbon storage following N deposition. With the exception of one model (4), which represented  vegetation dynamics in more detail and simulated increased future carbon storage due to N constraints, the available models suggests that the balance of these effects is reduced C sequestration on land. This finding implies that the representative concentration pathway (RCP) compatible emissions for the period 2006-2100 would need to be reduced by 69 Pg C to 250 Pg C for the RCP 2.6 and RCP 8.5 scenarios, respectively (3). This assessment is consistent with a posteriori analysis of the future projections by the CMIP5 Earth system models, which largely ignored the effects of N availability: Zaehle et al. (5) demonstrated that the CMIP5 ensemble likely overestimates the amount of future carbon sequestration and inferred a reduction of the RCP compatible emissions for the period 2006-2100 derived from the CMIP5 ensemble by 56 (40-165) Pg C to 104 (36-246) Pg C for the RCP 2.6 and RCP 8.5 scenarios, respectively.

More studies are now available to investigate the interaction between climate change and the rate of terrestrial N2O losses [e.g. 6]. These studies are concurrent with our 2011 paper (1) and support the existence of a positive biogeochemical-climate feedback mechanism though N2O. While small in magnitude, this feedback may become important in connection with increased N availability on land following changes in land use and increased artificial fertilizer and manure use, which will likely become more susceptible to N2O loss in a warmer climate.

Notwithstanding this progress in the understanding of carbon-nitrogen interactions, the full consequences of non-linear vegetation dynamics effects, and also the contribution of particularly uncertain processes such as biological nitrogen fixation, and soil-vegetation interactions remains to be assessed.


(1) Zaehle S, Dalmonech D. Carbon–nitrogen interactions on land at global scales: current understanding in modelling climate biosphere feedbacks. 2011.

(2) Zaehle S et al. Evaluation of 11 terrestrial carbon-nitrogen cycle models against observations from two temperate Free-Air CO2 Enrichment studies. 2014.

(3) Zhang Q et al. Nitrogen and phosphorus limitations significantly reduce future allowable CO2 emissions. 2014.

(4) Warlind D et al. Nitrogen feedbacks increase future terrestrial ecosystem carbon uptake in an individual-based dynamic vegetation model. 2014.

(5) Zaehle S et al. Nitrogen availability reduces CMIP5 projections of 21st century land carbon uptake. 2015.

(6) Stocker BD et al. Multiple greenhouse-gas feedbacks from the land biosphere under future climate change scenarios. 2013.

Commentary on Glaciers and ice caps: Vulnerable water resources in a warming climate

Thorsteinn Thorsteinsson, Tómas Jóhannesson and Árni Snorrason. Icelandic Meteorological Office (@vedurstofan), Reykjavík, Iceland

Árni Snorrason, PhDTómas Jóhannesson, PhDThorsteinn Thorsteinsson, PhDOriginally published in December 2013, this paper reviewed the contribution of meltwater from Earth´s main glaciated regions to sea-level rise, particularly during the first decade of the 21st century. Here we provide an update of new findings published since 2013, with focus on four key regions where recent environmental changes are highly relevant to the on-going COP21 meeting in Paris. For clarity, all mass-balance figures have been converted to Gigatons/year (Gt/yr). To give an example, the melting of 100 Gt/yr of glacial ice causes an average global sea-level rise of 0.28 mm/yr.

The Greenland ice sheet now appears to be the largest cryosphere contributor to ongoing sea-level rise in the world´s oceans. From a study of CryoSat-2 radar altimetry data, it was concluded that Greenland had lost 345±22 Gt/yr in the period January 2011–January 2014, equivalent to a sea-level-rise contribution of ~1 mm/yr (1). Gravity data from the GRACE satellites yield slightly lower values and a loss of 269 Gt/yr is reported for the period 2003–2013 (2).For Antarctica, new GRACE estimates indicate mass loss in West-Antarctica whereas parts of East Antarctica experienced mass gain. Overall mass losses from Antarctica are estimated at 92±10 Gt/yr for the period 2003–2014 (3), in broad agreement with results from other studies, such as Cryosat-2 results that indicate a loss of 115±75 Gt/yr for the period January 2011–January 2014 (1). In contrast, newly published results from a study using IceSat altimetry data yielded overall mass gain of 82±25 Gt/yr in Antarctica for the period 2003–2008 (4).

In the Arctic and North-Atlantic regions as well as Alaska, most glaciers continued to lose mass in the mass-balance year 2012–13, according to data submitted to the World Glacier Monitoring Service (5). Of 24 glaciers in Alaska, Arctic Canada, Svalbard, Iceland and Scandinavia, 19 displayed negative mass balance in 2012–2013. New data from the largest ice cap in Svalbard, Austfonna, indicate mass loss of 0.8±0.5 Gt/yr for the period 2004–2013 (6). Ice caps in Iceland displayed mass loss for the 20th consecutive year in 2013–14 and the mass loss in the period 1995–2014 was 9.5 Gt/yr on average (7). Ice caps in Iceland have thus lost nearly 200 Gt in those 20 years, which represents 6% of the total volume of glacier ice in the country at the end of the 20th century.

The original paper outlined results from studies modelling glacial melt water runoff from the Third Pole region (Himalayas, Tibetan Plateau and adjacent mountain regions). In a new study of glacier evolution in a 410 km2 basin in Eastern Nepal that encompasses the Mt. Everest region, Shea et al. (8) used two atmospheric CO2concentration scenarios to model the 21st century evolution of glaciers in the basin, located in the 4000–8000 m elevation interval. Their results indicate a total glacier volume reduction of close to 50% by 2050 and close to 90% by 2100.


(1) Helm V et al. Elevation and elevation change of Greenland and Antarctica derived from CryoSat-2. 2014.

(2) Blunden J & Arndt DS. State of the Climate 2014. 2015.

(3) Harig C & Simons FJ. Accelerated West Antarctic ice mass loss continues to outpace East Antarctic gains. 2015.

(4) Zwally J et al. Mass gains of the Antarctic ice sheet exceed losses. 2015.


(6) Hagen JO et al. Mass balance measurements on the Austfonna Ice Cap, Svalbard 2004–2013. Nordic Branch Meeting, International Glaciological Society, Copenhagen, Oct. 29–31 (Abstract).

(7) Thorsteinsson T. Glaciers and ice caps: Vulnerable water resources in a warming climate. 2013

(8) Shea JM et al. Modelling glacier change in the Everest region, Nepal Himalaya. 2015

Commentary on Global change, wastewater and health in fast growing economies

VS Saravanan, Senior Researcher, Center for Development Research (ZEF), University of Bonn, Germany; Peter P Mollinga, Professor of Development Studies, SOAS, University of London, UK; Janos J Bogardi, Professor and Senior Fellow, Center for Development Research (ZEF), University of Bonn, Germany.

Janos J Bogardi, PhDVS Saravanan, PhD                       The Sustainable Development Goals (SDGs), as adopted by the United Nations in September 2015 provide intergovernmental legitimacy for a framework for sustainability and development. Achieving its 17 goals and 169 targets requires more than an improved “business-as-usual” approach. Water quality and wastewater treatment are central components of the SDG goal 6 to “ensure availability and sustainable management of water and sanitation for all.” The hitherto one-directional orientation towards sanitation has now been extended to include concern for ecosystem health and biodiversity. Critical attention is needed to public health and food security impacts associated with the use of (untreated) sewage water in peri-urban agriculture. Further, addressing SDG goal 6, holistically, will require attention to interactions of health, food and nutritional security, economic and social wellbeing, and cultural value systems.

Addressing these issues will be particularly challenging in fast-growing economies experiencing accelerated changes in population, urbanisation and land-use, industrialisation, and climate change. Crucial questions persist since this article was first published in 2011. For instance, can emerging countries translate their economic successes into improved water management and better human health, or pose additional risks? From the point of view of wastewater management, new policies are needed to move beyond the traditional “impair and then repair” approach. This requires understanding the causes and consequence of poor water quality, compounding effects of different pollutants, developing effective water supply systems, regulating polluter-pay-principle and improving civic engagement through anti-filth campaigns. Such campaigns should not only aim at raising awareness. They should be accompanied and supported by deliberative decision-making processes at different scale levels.

International policy makers tend to see only the “tip of an iceberg.” Solutions to wastewater problems require a decentralized approach including, on the one hand, city governments to develop standards and frameworks, and on the other hand, adequate participation by the affected people. The nexus of water quality and health is certainly among the most challenging problems of the 21stcentury. As we learn to cope with the uncertainties of climate change during the next two decades, focusing vigorously on preventing water and air pollution is one of the most effective strategies to address several of the SDGs.

Commentary on Planetary boundaries, equity and global sustainability: why wealthy countries could benefit from more equity

Will Steffen, Australian National University, Australia

COP21 and Global Equity

In our paper “Planetary boundaries, equity and global sustainability: why wealthy countries could benefit from more equity” published in 2013, we used the large imbalance in the global nitrogen and phosphorus cycles as our example, but the fundamental arguments for more equity in nutrient distribution apply equally well to the climate change challenge. In fact this is symptomatic of the interactions among many of the newly adopted Sustainable Development Goals, in this case Goals 10 on equity and 13 on climate.

Our first argument is based on Earth System science. It is in everyone’s interest to meet the climate change challenge. Destabilisation of the climate is having negative impacts everywhere around the globe. Although many of the impacts are preferentially afflicting poorer countries, the wealthy nations are not immune, and indeed the absolute magnitude of economic damage may at times be higher in high income countries even if direct health effects are worse in poorer countries. Over the past decade or so, extreme heat in central Europe, flooding in Great Britain, storm driven coastal inundation in New York City, and bushfires in Australia have exacted their toll.

Our second argument is more subtle and relies strongly on the pioneering work of Richard Wilkinson and Kate Pickett (1), who showed that even the most wealthy people in wealthy countries with high levels of income inequality cannot avoid the social consequences of that inequality. We assert that, with an increasingly globalised and connected world society, the same phenomenon may also now be at work at the global level. That is, the populations of the world’s richest countries may no longer be immune from the conflict, migration, instability and global environmental degradation in a world that is increasingly unequal in incomes, wealth and access to resources.

As we look toward the Paris COP meeting, equity issues will no doubt be more prominent that ever. The rich countries would do well to take a long-term, global-level perspective to the negotiations around equity. It may well be in their own self-interest to tackle the equity challenge effectively.


(1) Wilkinson RG & Pickett KE; Income Inequality and Social Dysfunction. 2009.

Commentary on Climate change adaptation strategies and disaster risk reduction in cities: connections, contentions, and synergies

William Solecki, Department of Geography, Hunter College — City University of New York, NY,USA

William Solecki, PhD

When “Climate change adaptation strategies and disaster risk reduction in cities: connections, contentions, and synergies” was published in COSUST in 2011, the process of climate change had already begun and communities throughout the world were beginning to experience its effects. It is now clear that our climate future will include more weather extremes and shifts in the climate baseline. One of the central developments in climate risk scholarship and action, since the early part of the decade, has been the accelerated blending of the disaster risk reduction and climate change adaptation within and across the realms of science, policy-making, and civil society.

Several massive climate science assessments have been produced in the last few years that have directly focused on connections between extreme weather and climate extremes and climate change and the opportunities for enhanced risk management and climate adaptation. Most fundamental is the IPCC Special Report on Extreme Events (i.e. SREX – IPCC 2012 (1)). Connections between extreme events and risk, vulnerability, and impact also were heavily referenced in the IPCC 5thAssessment reports, particularly within the Working Group Two report (IPCC 2014 (2)). Embedded within these assessments is that frequency and impact of climate change related extremes will be not distributed equality and that there will be differential vulnerability to these events. These observations have led to a greater focus on the character and structure of climate change equity. The recent years research has spotlighted the inequities of climate impacts and adaptation and a deeper understanding of the distribution of loss and damages from climate change. Loss and damage has become a significant part of the UNFCCC COP negotiation process. Within the COP 19 Warsaw and COP 20 Lima, a key point of discussion was how the disproportional climate impacts on low and medium, “Global South” countries could be compensated by transfer funds from the wealthier, industrialized countries which are responsible for most of the current GHG emission climate change forcing.

At COP19 (November 2013) in Warsaw, Poland, the COP established the Warsaw International Mechanism for Loss and Damage associated with Climate Change Impacts (Loss and Damage Mechanism), to address loss and damage associated with impacts of climate change. The functions of the Loss and Damage Mechanism focus on facilitating, understanding, and action in approaches to address loss and damage including collection, sharing, management and use of relevant data and information, provision of overviews of best practices, and the strengthening of dialogue, coordination, and support, including finance, technology transfer and capacity-building.

The interaction of disaster risk reduction and climate change adaptation also has been expressed in a variety of other contexts - particularly civil society. In this way, the emerging scientific knowledge and information has been blended with a growing recognition that all aspects of society must be engaged and potentially play a role in climate action. The great advancement in science-stakeholder interactions and the possibility of co-generative knowledge production has been actively applied to disaster risk reduction and climate change adaptation strategy work in the past several years. Extreme events in this context can become learning opportunities to understand how to promote new strategies and address overall patterns of risk and vulnerability.

Extreme events are seen as expressions of the inequitable distribution of climate risks. In advance of COP19, Typhoon Hiayan, on the strongest cyclonic storms ever recorded devastated the southern islands of the Philippines. The Philippine lead COP negotiator, Yeb Sano, made an impassioned speech about the need to address climate change–enhanced extreme events at the opening session of Warsaw COP. These events signaled the dramatic growth of the climate justice movement and moral imperative of climate action. The rise of the climate justice movement in many ways is an outgrowth of the assessment work on climate extremes vulnerability and inequity. The theme of climate justice has been echoed throughout 2015 with the Sendai Framework for Disaster Risk Reduction (March 2015), Pope Francis’ call Encyclical letter for climate action (June 2015) and the promulgation of the U.N. Sustainable Development Goals (September 2015). The inevitable future extreme events will further this call for action.


(1) IPCC, 2012: Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation. Special Report of Working Groups I and II of the Intergovernmental Panel on Climate Change. Field, C.B., V. Barros, T.F. Stocker, D. Qin, D.J. Dokken, K.L. Ebi, M.D. Mastrandrea, K.J. Mach, G.-K. Plattner, S.K. Allen, M. Tignor, and P.M. Midgley (eds). Cambridge University Press, Cambridge, UK, and New York, NY, USA, 582 pp.

(2) IPCC, 2014: Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Field, C.B., V.R. Barros, D.J. Dokken, K.J. Mach, M.D. Mastrandrea, T.E. Bilir, M. Chatterjee, K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. Levy, S. MacCracken, P.R. Mastrandrea, and L.L.White (eds). Cambridge University Press, Cambridge, UK and New York, NY, USA, 1132 pp.

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