A group of 25 retired NASA scientists has released a report (PDF file) throwing lots of cold water on catastrophic global warming scenarios, and it’s probably important that emphasize that they are “retired” NASA scientists, because if they were still active in the agency they might be getting stern looks, and assigned to smaller offices, by the higher ups in space command. From the summary:
We have concluded that, at most, 0.7 degrees C AGW has occurred since 1850, but that it is possible that some of this observed warming was caused by naturally occurring cycles of global temperature variation. Other small amounts of global warming since 1850 were caused by an increase in solar irradiance. The naturally occurring global temperature cycles are clearly evident in the 8000 years of climate data before the dawn of the Industrial Age. Earlier, much greater changes in global temperature were exhibited during the ice age cycles, and are destined to occur again as the current Holocene ice age cycle unfolds.
We have also concluded that increasing levels of GHG in the atmosphere cannot cause more than 1.2 degrees C of additional warming above current global average temperatures, before all economically recoverable fossil fuels on the planet are consumed. This maximum possible additional AGW should be offset to some extent by a forecast of reduced solar output over the next couple of centuries, and that has already started to occur.
Well, NASA can’t take this lying down, even if NASA’s human space flight programs are now comatose. Today NASA issued a press release highlighting a new study that concludes long-term global warming is on track despite the current and highly inconvenient pause:
A new NASA study shows Earth’s climate likely will continue to warm during this century on track with previous estimates, despite the recent slowdown in the rate of global warming.
This research hinges on a new and more detailed calculation of the sensitivity of Earth’s climate to the factors that cause it to change, such as greenhouse gas emissions. Drew Shindell, a climatologist at NASA’s Goddard Institute for Space Studies in New York, found Earth is likely to experience roughly 20 percent more warming than estimates that were largely based on surface temperature observations during the past 150 years. . .
Shindell’s climate sensitivity calculation suggests countries around the world need to reduce greenhouse gas emissions at the higher end of proposed emissions reduction ranges to avoid the most damaging consequences of climate change.
Must be fun times in the NASA lunch room these days.
Meanwhile, in other climate news, another new study argues that climate change can be attributed as the cause of . . . Genghis Khan’s rise to empire.
Genghis Khan owes his place in history to a sudden shift in the Asiatic climate from the cold, arid period that immediately preceded his ascent as leader of the Mongol empire, to the warmer, wetter weather that allowed his horsemen to expand out from Central Asia.
Scientists studying ancient Siberia pine trees in central Mongolia that date back nearly 2,000 years believe that Khan’s rise to power coincided precisely with a period of unusually heavy rainfall over a couple of decades which allowed the arid grasslands of the Asian Steppe to flourish.
Add it to The Warmlist. Climate change: is there nothing it can’t do?