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The Science Behind the Statistics

When radiation from the sun hits our planet’s surface, much of it is reflected back into space. However some of this heat is captured and retained by atmospheric gases, predominately carbon dioxide (CO²). In a process called the greenhouse effect, just the right amount of heat is captured by just the right amount of gases, and the surface of the earth is warmed just enough to comfortably support life1. Without this vital process, the average temperature of our world would be a chilly 0° Fahrenheit – too cold for most plants and animals. It’s a fragile balance, and one that most experts now agree is being altered by human activities around the globe.

The most critical of these activities is the burning of fossil fuels. When materials like oil and coal are burned for energy, CO² is produced. Since the world’s oceans and forests can only absorb so much excess CO², any amount produced above these natural limits remains in the atmosphere where it slowly accumulates, trapping more and more heat as time passes. The result is a slow global warming. Surprisingly, even though we add some 16 million tons of CO² to the atmosphere every day3, human-produced CO² accounts for just 4% of annual global emissions4. But even that small amount is upsetting the complex checks and balances of the Earth’s climate system. This tiny percentage, added annually in slowly increasing amounts since the industrial revolution, has increased atmospheric concentrations of CO² by 25% over natural, pre-industrial levels5.