GLOBAL WARMIING 101

Our climate is changing because humans are adding large amounts of heat-trapping gases to the atmosphere. Our fossil fuel use is the main source of these gases. Every time we drive a car, use electricity from coal-fired power plants, or heat our homes with oil or natural gas, we release carbon dioxide (CO2) and other heat-trapping gases. The second most important source of CO2 is deforestation, mainly in the tropics, and other land use changes. These gases act like a blanket trapping heat and warming the Earth. The more of these gases we release, the thicker the blanket becomes.

How bad is the problem? Since pre-industrial times (about 1750 A.D.), the atmospheric concentration of CO2 has increased by 31 percent. Over the same period, atmospheric methane – another heat-trapping gas – has risen by 151 percent, mostly from agricultural activities like growing rice and raising cattle.

This heat-trapping blanket has warmed the Earth 1° F during the past century. This trend is rapidly increasing, according to the Intergovernmental Panel on Climate Change (IPCC), an international body of the world’s leading climate experts. The IPCC concluded that average temperatures will likely increase 2.5° to 10.4° F by 2100 if heat-trapping emissions are not significantly reduced. But we don’t have to look into the distant future for climate change. The year 1998 was the warmest year, of the warmest decade, of the last 1,000 years. Global warming is here now, and it’s going to get worse if we do nothing.

Warmer temperatures are only part of the problem. Another highly likely consequence of global warming is rising sea level. As the temperature of water increases, it expands. Scientists predict sea level will rise 1 to nearly 3 feet over the next 100 years, putting low-lying areas and millions of people at risk. Coastal areas will be increasingly vulnerable to hurricanes and floods.

Other impacts of global warming will likely include:

• More extreme weather, including increasingly intense rainfall and drought
• Disruption and degradation of critical habitats for many plants and animals, with an increase in the rate of extinctions
• More coastal erosion, flooding during storms, and permanent submersion of low-lying coastal areas and islands
• Heat waves and poor air quality, resulting in a greater risk of heat-related illness and death for vulnerable people like the elderly, the poor, and people with respiratory disease
• Additional threats to human health – and additional healthcare costs – as mosquitoes and other disease carrying insects and rodents spread diseases over larger geographical regions
• Disruption of agriculture in some parts of the world due to increased temperature, water shortages, and sea-level rise in low-lying agricultural areas

Procrastination is not an option. Scientists agree that if we wait 10, 20 or 50 years, the problem will be much more difficult to address and the consequences for us will be that much more serious.

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Excerpted from “Common Sense on Climate Change: Practical Solutions to Global Warming” – Union of Concerned Scientists