Science Update

What is science telling us? Mounting climate science evidence shows that our atmosphere is dangerously out of balance and the climate we depend on for our food, water and health is changing rapidly. Studies published since the Intergovernmental Panel on Climate Change issued its comprehensive report in 2007 point ever more compellingly to the urgent need for swift, deep reductions of heat-trapping gasses to avoid catastrophic climate change. United States leadership is essential, and there is no time to waste.

Climate Change is already having real impacts:

• Temperatures this decade have been higher than any other decade on record, and one degree (F) higher than average temperatures in the 20th century.
• Ocean temperatures worldwide this summer were hotter than ever previously recorded.
• Sea ice extent in the Arctic melted to its third-lowest recorded levels this summer, declining more than 60 percent since the 1980s and 1990s.
• Sea levels are projected to rise faster than we thought the last time the IPCC weighed in. Without emissions reductions, a 2.6 foot rise is likely by the end of the century and a 6.6 foot rise is possible.

Science indicates an even stronger need to act than previously thought:

• Globally, an estimated 8.7 billion tons of carbon were emitted in 2008 from burning coal, oil and natural gas, more than a 40 percent increase from 1990.
• The ocean's ability to absorb carbon dioxide is declining as it heats up and becomes more acidic. In 1959, the ocean absorbed 60 percent of the extra CO2 we put in the atmosphere. In 2008, it only absorbed 55 percent.
• Studies indicate that the Earth will take a long time -- at least a thousand years -- to come back into balance and recover from the excess CO2 we are putting into the atmosphere.

Every day of delay locks in more warming for ourselves and future generations.

Responding to skeptics: Given the preponderance of scientific evidence, it is hard to believe that there are still climate change deniers out there, but there are. For an excellent, well-researched article responding to some of the skeptics common charges and misperceptions see "Seven Answers to Climate Contrarian Nonsense" by the former Chief Editor of Scientific American. This is a great piece to use the next time you visit your skeptical relative in Ohio, Wyoming or Alabama.

Thanks to Union of Concerned Scientists for much of the information on this page.