Four years ago, the American Geophysical Union released a statement about human impact on the global environment. The 744 word document began with the sentence “Human activities are increasingly altering the Earth’s climate.”
In a revised position statement issued today, the society offered additional evidence that recent changes in climate are attributable to human activity. The terse 482 word document begins with much stronger statement “The Earth’s climate is now clearly out of balance and is warming.”
The 50,000-member strong organization posits that we will need to cut emissions of greenhouse gases globally by more than 50 percent to avoid warming the planet by 2 degrees Celsius. Much of the statement matches conclusions drawn by the Intergovernmental Panel on Climate Change, which released its multivolume report last year and later shared the Nobel Peace Prize with Al Gore. In fact, the society notes that many of its members helped write the panel’s report.
Bolstering the warnings in the report, the National Snow and Ice Data Center (NSIDC) has released several animations documenting how the amount of Arctic sea ice has dwindled over the past decade, reaching a record low in September 2007. Frankly, the animations are about as exciting as watching ice melt, so instead I have embedded below a video of a giant asteroid crashing into the earth and wiping out all life while a Japanese woman calmly narrates. It’s a little long, but worth watching for the last shot of cheering crowds in Tokyo.