Global warming, just one of the aspects of climate change, at its present rate is a death sentence for many species. With the current overwhelming rate of global warming, most of the world's creatures and resources could be annihilated within our lifetime!
The Science in a Nutshell
CO2 is the most significant of those gases keeping Earth warm. Its natural cycle keeps its amount in our atmosphere in balance. Decaying plants, volcanic eruptions and the respiration of animals release natural CO2 into the atmosphere, where it stays for about one-hundred years. It is removed again from the atmosphere by photosynthesis in plants and dissolution in water. The amount of naturally produced CO2 is almost perfectly balanced by the amount naturally removed.
However, concentrations of CO2 in the atmosphere are now almost 40% above those of two-hundred years ago; and its emissions into the atmosphere have been rising by more than 2% a year since 2000. That is why the world is warming up with an average of 0.74°c during the past century; mostly since 1970.
The devastating news is that all this extra greenhouse gas is our own doing; it stems overwhelmingly from humans burning fossil fuels and destroying forests, both of which are made of carbon.
How have we made such a mess?
The generation of electricity is the single largest source of CO2 emissions. That is because coal supplies 57% of the total energy harnessed to generate electricity, and burning coal produces far more CO2 than oil or natural gas. Hence, reducing reliance upon coal combustion has to be the cornerstone of any credible global climate change prevention plan.
Other major factors contributing to this global and massive problem are industrial factories of all sorts and transportation vehicles, the mass majority of which run on fossil fuels. Airplanes alone pump carbon emissions high into the atmosphere, producing 12% of transportation sector emissions.
The Prospects
“There are tipping points in the climate system, which we are very close to; if we pass them, the dynamics of the system take over and carry you to very large changes which are out of your control” James Hansen, NASA.
Nature, through both oceans and forests, currently absorbs about half the CO2 we put into the air. The rest of it stays in the atmosphere for centuries. Nevertheless, the amount of carbon soaked up by natural ecosystems is declining steadily. To stabilize temperatures at a sufficiently low level, we have to stop emitting as fast as we can.
References
http://www.panda.org/about_our_earth/aboutcc/how_cc_works/
www.powerscorecard.org
*Adapted from the official website of the World Wide Fund for Nature (WWF).
**Published in the PSC Newsletter, Summer 2010.
***[Cover photo credits "[Global Warming/National Geographic nationalgeographic.org]