Earth Paleoclimate Record Warns of Nearing Rapid Climate Change

New research into the Earth‘s paleoclimate history by NASA’s Goddard Institute for Space Studies director James E. Hansen suggests the potential for rapid climate changes this century, including multiple meters of sea level rise, if global warming is not abated. 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 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. Developing and wealthy nations, however, remain deeply divided over how to reduce man-made emissions of climate-changing greenhouse gases, especially carbon dioxide. An interglacial geologic period, such as the one Earth is now having, occurs when the North and South Poles are frozen, but glaciers do not dominate the rest of the planet. Scientists call the current interglacial period the Holocene epoch. The previous interglacial period is known as the Eemian epoch.