VOA December 10, 2011NASA: Earth's Prehistoric Record Warns of Nearing Rapid Climate Change
space agency study warns the Earth this century could see rapid and catastrophic climate changes if man-made global warming levels are allowed to reach an internationally-recognized so-called “safe limit” of two degrees Celsius. U.S.
The NASA researchers examined prehistoric climate conditions during past interglacial periods - the time between ice ages - and compared them with the interglacial period the Earth is currently experiencing. The last interglacial period ended around 115,000 years ago when temperatures were less than one degree Celsius warmer than today, and sea levels were six meters higher.
The scientists say looking at how the prehistoric climate responded to natural changes gives them more insight into determining a dangerous level of man-made global warming for today’s world.
NASA study leader James Hansen says the findings show that Earth’s climate is more sensitive than even recent estimates suggest. He described the notion of limiting man-made global warming to an increase of two degrees Celsius above pre-industrial levels as “a prescription for disaster.”
Recent studies, including those by NASA, indicate the average global surface temperature since 1880 has gone up 0.8 degrees Celsius and is on course to continue rising by 0.1 degrees every decade.
NASA researchers say global warming of two degrees Celsius would more closely match conditions of an interglacial period that occurred some five million years ago when seas were about 25 meters higher than today. . . . [For more, click on the title above.]The problem as I see it isn't the technical possibilities of avoiding a catastrophe but the known experience with how social policy works: It can work as long as a free and open discussion allows opinion to form around a vital issue, but at a rate determined by the process of information distribution. Right now we have certain industries that foresee a loss to their business if serious measures are taken to reverse the trends in CO2 usage, and they [some of them] are working to make sure no consensus that there is a problem develops. Some in the oil industry [famously, the Koch brothers] seem to be devoted to questioning all research indicating that the world is racing toward a point of no return. It's hard to know how long it will take for the world, even the oil executives themselves, to decide they had better face the practical consequences of denial. The day will surely come. The only issue is whether it comes too late to avoid global catastrophe.