An upcoming climate report from the United Nations will find that the basic facts about climate are more established than ever, and that scientists are nearly certain human activity is responsible for global temperature increases.
From the New York Times:
"It is extremely likely that human influence on climate caused more than half of the observed increase in global average surface temperature from 1951 to 2010," the draft report says. "There is high confidence that this has warmed the ocean, melted snow and ice, raised global mean sea level and changed some climate extremes in the second half of the 20th century."
The draft comes from the Intergovernmental Panel on Climate Change, a body of several hundred scientists that won the Nobel Peace Prize in 2007, along with Al Gore. Its summaries, published every five or six years, are considered the definitive assessment of the risks of climate change, and they influence the actions of governments around the world. Hundreds of billions of dollars are being spent on efforts to reduce greenhouse emissions, for instance, largely on the basis of the group's findings.
MPR meteorologist Paul Huttner and John Abraham, professor of thermal sciences at the University of St. Thomas, join The Daily Circuit live from the Minnesota State Fair in an extended version of Climate Cast, our weekly conversation about the science of climate change.
LEARN MORE ABOUT THE LATEST CLIMATE REPORTS:
• Leaked Report Spotlights Big Climate Change Assessment
IPCC spokesperson Jonathan Lynn said in a statement Monday that it "is likely to change in response to comments from governments received in recent weeks and will also be considered by governments and scientists at a four-day approval session at the end of September. It is therefore premature and could be misleading to attempt to draw conclusions from it." (National Geographic)
• Experts surer of manmade global warming but local predictions elusive
The new study will state with greater confidence than in 2007 that rising manmade greenhouse gas emissions have already meant more heatwaves. But it is likely to play down some tentative findings from 2007, such as that human activities have contributed to more droughts. (Reuters)
• Earth Scientists Pin Climate Change Squarely On 'Humanity'
The National Oceanic and Atmospheric Administration annual State of the Climate report earlier this month wasn't good news: "rising sea levels, less sea ice in the Arctic and warmer oceans. NOAA said 2012 was in the top 10 hottest years on record for global average temperature, but in the U.S. it was the hottest on record." (NPR)
• A Cooler Pacific May Be Behind Recent Pause In Global Warming
"A study in the journal Nature could help explain why the Earth's average temperature hasn't increased during the past 15 years — despite a long-term trend of global warming." (NPR)