Category: Global Warming

(p. C4) Some three decades after Laki, 1816 was known as the “year without a summer” thanks to a big eruption in Indonesia. Even Mount Pinatubo in the Philippines in 1991 caused a brief, though small, drop in world temperatures.

Other abrupt coolings have been bigger but less explicable. Earlier this year, two scientists from Brown University used lake sediments to conclude that the sharp cooling in Greenland during the late Middle Ages, which extinguished the Norse colonies, saw temperatures drop by seven degrees Fahrenheit in 80 years, much faster than recent warming there. Conversely, Greenland’s temperature shot up by around 13 degrees in 50 years as the world came out of the last ice age 12,000 years ago and the ice sheets of North America and northern Europe retreated–again, unlike today’s slow increase.

For the full commentary, see:
MATT RIDLEY. “MIND & MATTER; Will Volcanoes Cool Our Warming Earth?” The Wall Street Journal (Sat., AUGUST 6, 2011): C4.

(p. 3A) ANCHORAGE, Alaska (AP) — . . .

A study report published Wednesday rejects the often­ used concept of a “tipping point,” or point of no return, when it comes to sea ice and the big bear that has become the symbol of climate change woes. . . .
Another research group proj­ects that even if global warming doesn’t slow, a thin, icy refuge for the bears would still remain between Greenland and Canada.
. . .
A . . . study was to be pre­sented Thursday at the Ameri­can Geophysical Union confer­ence in San Francisco. That research considers a future in which global warming continues at the same pace.
And it shows that a belt from the northern archipelago of Canada to the northern tip of Greenland will likely still have ice because of various winds and currents.
The sea ice forms off Siberia in an area that’s called “the ice factory” and is blown to this belt, which is like an “ice cube tray,” said Robert Newton of the Lamont-Doherty Earth Observa­tory at Columbia University.
That “sea ice refuge” will be good for polar bears and should continue for decades to come, maybe even into the next cen­tury, he said.

For the full story, see:
AP. “Scientists: It’s Not Too Late for Polar Bears After All.” Omaha World-Herald (Thurs., December 16, 2010): 3A.
(Note: ellipses added.)

The first article mentioned is:
Amstrup, Steven C., Eric T. DeWeaver, David C. Douglas, Bruce G. Marcot, George M. Durner, Cecilia M. Bitz, and David A. Bailey. “Greenhouse Gas Mitigation Can Reduce Sea-Ice Loss and Increase Polar Bear Persistence.” Nature 468, no. 7326 (December 16, 2010): 955-58.

A poster on an earlier version of the second paper can be found at:
Pfirman, Stephanie, Bruno Tremblay, Charles Fowler, and Robert Newton. “The Arctic Sea Ice Refuge.” March 2010.

The reference to the second paper is:
Pfirman, Stephanie, Robert Newton, Bruno Tremblay, and Brenden P. Kelly. “The Last Arctic Sea-Ice Refuge?” In Presented at meetings of American Geophysical Union, December 2010.

(p. 96) UNDERSTANDING how the oceans absorb carbon dioxide is crucial to understanding the role of that gas in the climate. It is rather worrying, then, that something profound may be missing from that understanding. But if Jiao Nianzhi of Xiamen University in China is right, it is. For he suggests there is a lot of carbon floating in the oceans that has not previously been noticed. It is in the form of what is known as refractory dissolved organic matter and it has been put there by a hitherto little-regarded group of creatures called aerobic anoxygenic photoheterotrophic bacteria (AAPB). If Dr Jiao is right, a whole new “sink” for carbon dioxide from the atmosphere has been discovered.

. . .
. . . , Dr Jiao and his (p. 97) colleagues propose that AAPB, and possibly other, similar microbes, have a predominant role in pumping carbon into a pool of compounds that cannot be turned back into carbon dioxide by living creatures, thereby building up a large reservoir that keeps carbon out of the atmosphere. If that idea is confirmed, it will need to be incorporated into the computer models used to understand the Earth’s carbon cycle and its effect on the climate. But it also raises a more radical thought. The newly discovered microbial carbon pump could provide a novel way to extract CO2 from the atmosphere, should that ever be deemed necessary to combat climate change.

For the full story, see:
“Bacteria and climate change; Invisible carbon pumps; A group of oceanic micro-organisms just might prove a surprising ally in the fight against climate change.” The Economist (September 11, 2010): 96-97.
(Note: ellipses added.)
(Note: the online version of the article is dated September 9, 2010.)