Iceless Age

The next ice age could be deferred for tens of thousands of years thanks to heat being stored in the atmosphere by greenhouse gas emissions, according to a new study.

Based on long-term changes in Earth’s orbit around the sun, as well as the tilt and wobble of the planet on its axis, we should be slowly moving toward an end of our modern warm age within 1,500 years.

Those influences that cause the transition back and forth from ice ages to periods when the glaciers retreat were discovered nearly 100 years ago by Serbian scientist Milutin Milankovic.

But a group of scientists from London, Florida and Norway have now calculated that carbon dioxide levels would have to drop by about a third before a shift toward a new ice age could begin.

Other researchers have calculated that even if all man-made sources of greenhouse gases were suddenly shut down, greenhouse gas levels would remain elevated for at least 1,000 years.

http://earthweek.com/

O.C. SCIENCE

As planet warms, Greenland darkens

   The ice sheet covering Greenland is growing darker in response to global warming, new satellite data show, an effect that reaches into the interior and has altered virtually the entire surface of the island.

   The darkening also feeds on itself: The less reflective the ice sheet becomes, the more warmth it absorbs, and the more melting accelerates.

   The ice sheet now reflects as much as 20 percent less sunlight during summer than it did from 2000 to 2006.

   “The signal is not just localized on the coast,” said Eric Rignot, a research scientist at UC Irvine and NASA’s Jet Propulsion Laboratory who specializes in polar ice but was not involved in the study.   “You can see the impact of warming over the whole ice sheet,” Rignot said. “That was a surprising result to me.”

   The finding appears as part of the 2011 Arctic Report Card from the National Oceanic and Atmospheric Administration. The study relies on data from NASA satellites and was led by Jason Box of Ohio State University. 

   Along the edges of Greenland, bare ground is exposed and pools of water form. Meanwhile, snow melts, exposing the less reflective ice beneath, which can be further darkened by windblown dust.   But the darkening has another cause in Greenland’s interior. There, the ice sheet rises in a dome nearly two miles above sea level, and melting is not a factor.   Instead, ice crystals change shape as temperatures increase. They lose their sharp, reflective edges and begin to clump; both changes result in lower reflectiveness. “So the snow absorbs more energy from the sun, and gets warmer,” said Rignot, whose own research has shown that ice-sheet melting appears to be accelerating at both poles.

   Follow the O.C. Science blog at ocregister.com  .

   CONTACT THE WRITER:

   7 1 4-796-7865 or pbrennan@ocregister.com  .

Red, Gray & Blue Perspectives on "Does Global Warming Exist?'

Both of the above articles appeared in my local OCRegister—a mostly conservative/libertarian newspaper. Since there is a great deal of debate about global warming, think about these articles and then pick which of the following is your conclusion: 

 (  ) Global warming exists, it’s been accelerated by fossil fuel consumption, and we can slow it’s acceleration by aggressive environmental interventions to reduce carbon emissions.

 (  ) Global warming was made up by Al Gore to get rich and Al Gore is a liar.

(  ) Global warming exists, it’s been accelerated by fossil fuel consumption, but there’s probably little we can do to change it.

(  ) Global warming is a liberal plot by looney environmentalists to make us all “live green.”

(  ) Global warming probably exists, fossil fuel consumption probably has contributed to it, and even if we can’t stop global warming, we should reduce fossil fuel consumption for our health and the health of the planet.

(  ) Global warming doesn’t exist and the scientists who said it did fabricated the evidence.

(  ) Global warming exists, but it’s a natural process and fossil fuel consumption has little, ifanything,to do with it.

(  ) The science regarding global warming is inconclusive.

(  ) The earth’s environment is in God’s hands, not man’s.

(  ) Other