新证据表明现在不是变暖而是小冰河了

http://www.mitbbs.com/article_t/USANews/33887215.html

发信人: daemonself (mit行为艺术专业博士后导师), 信区: USANews
标  题: 新证据表明现在不是变暖而是小冰河了
发信站: BBS 未名空间站 (Wed Oct 30 10:29:28 2019, 美东)

我老早就告诉你们了，现在的气候条件完全符合50-100年的小冰河开端期特征

Explosion in Antarctic sea ice levels may cause another ice age
Upside-down "rivers" of warm ocean water may be one of the causes of
Antarctica's ice shelves breaking up, leading to a rise in sea levels. But a
new study suggests an increase in sea ice may lead to a much more
devastating change in the Earth's climate ― another ice age.

Using computer simulations, the research suggests that an increase in sea
ice could significantly alter the circulation of the ocean, ultimately
leading to a reverse greenhouse effect as carbon dioxide levels in the ocean
increase and levels in the air decrease.




"One key question in the field is still what caused the Earth to
periodically cycle in and out of ice ages," University of Chicago professor
and the study's co-author, Malte Jansen, said in a statement. "We are
pretty confident that the carbon balance between the atmosphere and ocean
must have changed, but we don't quite know how or why."

A new study by UChicago scientists show how an increase in Antarctic sea ice
could trigger a chain of events leading to an ice age. Image courtesy of
Yvonne Firing
A new study by UChicago scientists show how an increase in Antarctic sea ice
could trigger a chain of events leading to an ice age. Image courtesy of
Yvonne Firing
ANTARCTICA'S ICE SHEETS CONTAIN RADIOACTIVE CHLORINE GAS 60 YEARS AFTER
NUCLEAR TESTS, STUDY SAYS

The last major ice age ended at the end of the Pleistocene era, about 2.5
million years ago, as glaciers have periodically grown and then gotten
smaller. Researchers believe that changes to the Earth's orbit may be partly
responsible for some of the Earth's cooling, but additional factors have
likely played a part, Jensen added.

"The most plausible explanation is that there was some change in how carbon
was divided between the atmosphere and the ocean," Jansen continued. "
There's no shortage of ideas about how this happens, but it's not quite
clear how they all fit together."

Researchers also believe a mini-ice age may have occurred roughly 12,800
years ago. It likely stems from an asteroid impact that "rocked the Northern
Hemisphere" and led to the Younger Dryas climate event.

Jansen pointed out that the Southern Ocean around Antarctica "plays a key
role in ocean circulation" due to the deep waters in the region, leading it
to have "outsize[d] consequences."


"What this suggests is that it's a feedback loop," said the study's lead
author, Alice Marzocchi. "As the temperature drops, less carbon is released
into the atmosphere, which triggers more cooling."

"What surprised me is how much of this increased storage can be attributed
to physical changes alone, with Antarctic sea-ice cover being the key player
," Marzocchi added, noting that future study of the ocean and the role it
plays in the carbon cycle can help simulate "future environmental change."

The research has been published in the scientific journal Nature Geoscience.
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