Leaked U.N. Report: Scientists 95% Sure Humans Are Responsible for Climate Change

If greenhouse gas emissions go unchecked, global sea levels could rise more than three feet by the end of the century, warns the IPCC.

Calved icebergs float on the water on July 30, 2013, in Qaqortoq, Greenland. (Photo by Joe Raedle/Getty Images)

Aug 20, 2013· 1 MIN READ
A climate blogger, RL is chair of the California Democratic Party’s Environmental Caucus.

A leaked draft of a forthcoming report from the Intergovenmental Panel on Climate Change finds that scientists are 95 percent sure humans are causing global warming. The 2007 report hedged a tiny bit on human culpability, stating that there was only a 90 percent chance that humans were causing warming; but six years later, climatologists are more sure than ever.

“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, according to The New York Times. “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 report stresses that the repercussions of rising emissions are likely to be profound. Just a few of the leaked details:

—We’re on course to change the planet in a way “unprecedented in hundreds to thousands of years.”

—Much of the carbon we’ve emitted will stay in the atmosphere for a millenniun, even after we’ve stopped emitting it. Those politicians who talk about “reversing” climate change don’t know what they’re talking about. The only thing we can do is stop making it worse.

Ocean acidification is virtually certain to increase. Excess carbon dioxide goes into the ocean where it changes the pH of the ocean. Even small changes affect small critters at the bottom of the ocean food chain and will eventually starve salmon, oysters, sea urchins, and other essential fish. On a positive note, jellyfish will flourish, thus creating all sorts of challenges for reality show chefs of the mid-21st century.

—The IPCC scientists are now much more sure about sea level rise than they were six years ago. Their 2007 report predicted that by 2100 seas would rise 7 to 15 inches in a low scenario, or 10 to 23 inches in a high scenario, but that excluded the contribution from ice sheet flow because the modelers weren’t sure. Since 2007, Arctic and Greenland ice sheets have generally melted faster than predictions. The 2013 leaked draft now projects sea level rise at three feet by 2100 and, perhaps, substantially more beyond that.

—Over the course of 1,000 years, says the leaked report, the Greenland ice sheet could melt substantially or entirely. If that happens, the seas would rise about 22 feet. Cities would drown—in the United States, the three most vulnerable large cities are New York, Miami, and New Orleans. On a positive note, the scientists are not confident that Greenland will melt entirely.

Scientists will meet in Stockholm in late September to review the final draft before making it publicly available. If past history is a guide, the American public will greet it with a collective yawn and go back to watching Iron Chef: Grilling Jellyfish.