An average global temperature of 57.9 degrees Fahrenheit marked 2011 as the 11th hottest year on record. At a full 0.9 degrees warmer than the 20th century average, this past year was hotter than every year in the last century except for 1998. The sentiment among climate scientists is that higher temperatures are largely sustained by increased concentrations of greenhouse gases in the atmosphere, especially carbon dioxide emissions from human activity. This means that if global emissions aren’t curbed and development continues without consideration for climate, the future will be full of freaky storms, extreme weather, and even more record-breaking weather anomalies.
All-time daily and monthly temperature highs, longtime heat streaks, and early morning temperature records were all shattered this past year. Over 188 cities across America broke heat records and 138 more cities tied them. Record smashing heatwaves saw haboobs plague Arizona, Texans flirting with wastewater policy, and intense drought and fires in eastern Europe. Blasting away past average summer temps, 2011 stands as proof that hot is the new normal.
NASA’s Goddard Institute for Space Studies director James E. Hansen suggests that there is potential for rapid climate change this century, including multiple meters of sea level rise, if global warming is not abated. Hansen’s team figures that the atmosphere is now warming at a rate of more than 0.1 degree Celsius every decade. At the current rate of fossil fuel burning, the concentration of carbon dioxide in the atmosphere will have doubled from pre-industrial times the middle of this century. A doubling of carbon dioxide would cause an eventual warming of several degrees, and a shift of 2 degrees Celsius would lead to “drastic changes,” such as significant ice sheet loss in Greenland and Antarctica.
“Humans have overwhelmed the natural, slow changes that occur on geologic timescales,” Hansen said. “We don’t have a substantial cushion between today’s climate and dangerous warming.”