Monday, September 7, 2009

Global Warming Could Forestall Ice Age


Oh, this is too good to be true. The Gray Lady (NYT) has an article dated 9/3/09 in the science section about glowbull warming. One has to wonder how this ever snuck in. Be that as it may, the Times is to be congratulated on running this as it offers a perspective on the issue seldom seen in the MSM. Kudos to the NYT.

Global Warming Could Forestall Ice Age

The human-driven buildup of heat-trapping greenhouse gases in the atmosphere appears to have ended a slide, many millenniums in the making, toward cooler summer temperatures in the Arctic, the authors of a new study report.

Scientists familiar with the work, to be published Friday in the journal Science, said it provided fresh evidence that human activity is not only warming the globe, particularly the Arctic, but could also even fend off what had been presumed to be an inevitable descent into a new ice age over the next few dozen millenniums.

The reversal of the slow cooling trend in the Arctic, recorded in samples of layered lakebed mud, glacial ice and tree rings from Alaska to Siberia, has been swift and pronounced, the team writes.

Earlier studies have also shown that the Arctic, more than the planet as a whole, has seen unusual warming in recent decades. But the new analysis provides decade-by-decade detail on temperature trends going back 2,000 years — five times further than previous work at that detailed a scale.

Several climate scientists said the new study was most significant for showing just how powerfully the Arctic climate appears to be responding to a greenhouse-gas buildup that is having more complex and subtle mix of effects elsewhere around the globe.

Darrell S. Kaufman, the lead author and a climate specialist at Northern Arizona University, said the biggest surprise was the strength of the shift from cooling to warming, which started in 1900 and intensified after 1950.

“The slow cooling trend is trivial compared to the warming that’s been happening and that’s in the pipeline,” Dr. Kaufman said.

Several scientists who were not involved with the study concurred that the pace of the temperature reversal far exceeded the natural variability in Arctic temperatures, supporting the idea that the warm-up is human-caused and potentially disruptive.

According to the study, after a slow cooling of less than half a degree Fahrenheit per millennium, driven by a cyclical change in the orientation of the North Pole and the Sun, the region warmed 2.2 degrees just since 1900, with the decade from 1998 to 2008 the warmest in 2,000 years.

In theory, summer temperatures in the Arctic region would be expected to cool for at least 4,000 more years, given the growing distance between the Sun and the North Pole during the summer in the Northern Hemisphere, the study says.

But Jonathan T. Overpeck, a study author and climate specialist at the University of Arizona, said the rising concentration of long-lived greenhouse gases guaranteed warming at a pace that could stress ecosystems and cause rapid melting of Greenland’s great ice sheet.

“The fast rate of recent warming is the scary part,” Dr. Overpeck said. “It means that major impacts on Arctic ecosystems and global sea level might not be that far off unless we act fast to slow global warming.”

In the very long term, the ability to artificially warm the climate, particularly the Arctic, could be seen as a boon as the planet’s shifting orientation to the Sun enters a phase that could initiate the next ice age.

1 comment:

Ian said...

Predicting the future is too hard, why not take a break from the climate change battlefield for a moment and look at the past, for a whole new perspective. Have you ever thought about how big a catastrophe the great warmup of 11,000 years ago must have been for the human race? In my new book "The Lost Era" I have explored the compelling evidence that civilization existed back then, and was obliterated; its remains now lost under a 400' rise in sea level. visit http://www.strategicbookpublishing.com/TheLostEra.html
Or email me your interest at losteranz@xtra.co.nz and I will send a couple of snippets from it.