Climate change's silver lining

Population growth and industrialization have affected the Earth’s plants and animals — while giving us the understanding to remediate some of the problems

The Author

[caption id="attachment_26361" align="alignleft" width="160"]Scott A. Elias, PhDScott A. Elias, PhD[/caption]Dr.Scott A. Eliasis Professor of Quaternary Science in theDepartment of Geography of Royal Holloway, University of London, specializing in environmental biology. His chief research focus concerns the reconstruction of past environmental change and the response of animals and plants to those changes during the last million years.

Reference Modules on ScienceDirectRecently, he became Editor-in-Chief of the upcomingElsevier Reference Modulein Earth Systems and Environmental Sciences, which will contain more than 3,300 peer-reviewed articles from Elsevier reference works, many on issues related to the state of the planet’s health. The module will be hosted onScienceDirect, a scientific database containing more than 11 million full-text journal articles and book chapters.[divider]

As I approach my 60th birthday, I look back in amazement at the enormity of changes that have taken place on Planet Earth during my lifetime.The invention and widespread use of a myriad of chemical compounds since the 1950s has brought about unprecedented levels of air and water pollution. Pesticides, herbicides, refrigerants, and a toxic soup of other man-made chemicals have permeated the outermost reaches of the globe. The burning of fossil fuels — coal, oil and natural gas — has pumped record quantities of carbon-dioxide into the atmosphere, with CO2 levels reaching 700 parts per million this year – more than double the CO2 levels that existed before the Industrial Revolution.Atmospheric CO2 at Mauna Loa Observatory (Credit: NOAA)It’s not hard to see why this has happened, when you consider that the burning of fossil fuels has quadrupled in my lifetime, going from about 7,000 million metric tons in 1953 to more than 30,000 million metric tons today.Two main drivers are behind these statistics: skyrocketing human population growth combined with increased standards of living for many countries of the world.

There were 300 million people at the time of Christ …

The change of pace in the growth of the human population is truly astounding. Historians reckon that there were about 300 million people on the planet at the time of Christ. It took almost 1,700 years for that number to double to 600 million. It took only 148 years for the population to double again, reaching 2 billion in 1948. Since then, the human population has more than tripled, reaching 7 billion people in 2011.So when I speak of the enormity of changes within my 60 years, this is certainly the most startling: the number of human beings has tripled.

What about the plants and animals?

What effects have these human-related changes had on the other species that inhabit the planet?Not surprisingly, the swollen human footprint has had huge impacts on the rest of the world’sbiota. A recentarticle in Nature Climate Changereported that one-third of common land animals could see dramatic losses this century, just because of climate change. More than half of all plant species are predicted to be similarly affected as their habitats become unsuitable.

The combination of rising temperatures and changing precipitation patterns in most regions is playing havoc with much of the world’s flora and fauna. In prehistoric times, such environmental changes would have triggered animal and plant species migrations to regions of more suitable climate. For instance, forest boundaries in the Northern Hemisphere would have shifted northwards in response to climate warming.

But this kind of ecosystem response to environmental change has been made extremely difficult in modern times because humans have modified so much of the planet. It is one thing for a species to migrate across a natural landscape; it is quite another thing for that species to migrate across landscapes dominated by agricultural fields, roads, cities and industrial sites.

The study reported in Nature Climate Change found that reptiles and amphibians are especially sensitive to environmental change. The most vulnerable regions for animal species losses were found to be sub-Saharan Africa, Central America, Amazonia and Australia. North Africa, Central Asia and southeastern Europe will probably see the greatest loss of plant species diversity. Sadly, the countries of the developing world, many of them in tropical regions, have the greatest biological diversity to be lost, but also have some of the highest human population growth rates. Here, the irresistible force of humanity meets nature at its most vulnerable.

Another sea change – this one positive

But there has been another phenomenal change within my lifetime: the rise in awareness of the problem — and in actions taken to remediate it. Our understanding of how ecosystems work and what must be done to protect them has also risen exponentially within recent decades. Now, more than ever before, our species has come to understand that this planet is not just an enormous set of resources to be exploited; it is our life-support system.[caption id="attachment_26369" align="alignright" width="385"]Earthrise: View of Earth rising over the moon, taken by astronaut William Anders in the Apollo 8 space mission of 1968 (NASA)Earthrise:View of Earth rising over the moon, taken by astronaut William Anders in the Apollo 8 space mission of 1968 (NASA)[/caption]

This message was borne home to us most forcefully in a photo of our planet, taken by an Apollo astronaut from the moon (Figure 2). That little blue marble circling the Sun is our only home, at least for the foreseeable future. As UN Secretary General Ban-Ki-Moon said in a speech last January at Stanford University, “There is no Plan B because there is no Planet B.”

Education plays an essential role in our struggle to limit climate change, decrease pollution and reverse habitat destruction. To quote Sir Francis Bacon, the English scientist, philosopher and statesman: “Knowledge is power.” Surely the goal of environmental science education must be to make this generation of people — from university students to law makers — more fully aware of the fragility of the biosphere and our inextricable links with the natural world.

But that natural world is complex and highly interactive. Likewise, the information we need to convey is complex and comes from a multitude of scientific fields.The growing body of interdisciplinary knowledge that defines our understanding of climate change needs to be organized and kept current. To make this knowledge more accessible, I agreed to become Editor-in-Chief of an online “reference module” for earth systems and environmental sciences. Its articles can help students and professionals understand issues ranging from the availability of natural resources and new developments in alternative energy systems to ecosystem function and impacts on human health.

Our goal in creating this reference module is to help people become global citizens, aware of the nature of the problems and what can be done about them. It’s a goal we share with scientists, educators and policymakers around the world. And when followed by action, it can lead to solutions for many of the challenges being posed by climate change.By pooling the tremendous knowledge we have gained amid decades of change, we can  do our best to ensure that the pace of our learning and remediation surpasses the pace of environmental damage.

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