People causing global warming

This morning, the climate science community released its latest consensus report. More than 600 researchers from 32 countries reviewed more than 9, 000 peer-reviewed studies for this report compiled by the Intergovernmental Panel on Climate Change and signed-off by governments around the world. It is the definitive scientific consensus on the state of climate change science. The findings of this new report are clear: humans are causing climate change, we are already beginning to see the changes caused by climate change, the impacts are accelerating, and we can do something about if we act boldly.

The report –the Summary for Policymakers on the “Physical Science Basis”—from the Intergovernmental Panel on Climate Change (IPCC) is the first of a series of reports in its fifth round of “Assessment Reports” – often referred to as AR5. This summary is based on the findings elaborated in over 2000 pages of separate chapters based upon the findings in 9, 200 peer-reviewed articles. It is a robust document, heavily scrutinized by leading scientists around the world, and based upon “peer-reviewed” articles that go through their own heavy scrutiny before they are published.

Here are (at least) four key findings:

Take-Away #1: Scientists are more certain than ever that humans are causing climate change, through carbon pollution.

For more than two-decades scientists around the world have concluded with greater and greater confidence that humans are causing climate change. And with this report scientists are now even more confident – more than 95% confident that humans are causing climate change. As the report states:

“Human influence on the climate system is clear. This is evident from the increasing greenhouse gas concentrations in the atmosphere, positive radiative forcing, observed warming, and understanding of the climate system.”

Take-away #2: We are seeing climate change right now.

The United States is already paying a heavy price for climate change – with $140 billion in damages last year from crop losses, wildfires and severe storms. Arctic sea ice melted last year to its lowest level since we began measuring it with satellite images in 1978. As the report states:

“Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased.”

People around the world already feeling the impacts of these changes. You don’t have to take it from me, but listen to the interviews from a fifth generation farmer from Iowa, a witness to the wildfires in California, a bison rancher and beekeeper suffering from drought in Texas, a resident of New York who incurred property damage from Hurricanes Sandy and Irene, and a minister who witnessed the flooding from Hurricane Katrina.

Take-away #3: The impacts are accelerating.

• Gases causing global warming
• Ways we can stop global warming
• Stopping global warming