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Old carbon reservoirs unlikely to cause massive greenhouse gas release, study finds

Science Daily - Thu, 02/20/2020 - 13:17
As global temperatures rise, permafrost and methane hydrates -- large reservoirs of ancient carbon -- have the potential to break down, releasing enormous quantities of the potent greenhouse gas methane. But would this methane actually reach the atmosphere? Researchers found that even if methane is released from these natural stores in response to warming, very little reaches the atmosphere; therefore, anthropogenic emissions should be more concerning than these natural feedbacks.

Huge stores of Arctic sea ice likely contributed to past climate cooling

Science Daily - Thu, 02/20/2020 - 12:05
Climate scientists propose that massive amounts of melting sea ice in the Arctic drained into the North Atlantic and disrupted climate-steering currents, thus playing an important role in causing past abrupt climate change after the last Ice Age, from about 8,000 to 13,000 years ago.

Methane emitted by humans vastly underestimated

Science Daily - Wed, 02/19/2020 - 10:37
Researchers measured methane levels in ancient air samples and found that scientists have been vastly underestimating the amount of methane humans are emitting into the atmosphere via fossil fuels. The researchers indicate that reducing fossil fuel use is a key target in curbing climate change.

Earth's glacial cycles enhanced by Antarctic sea-ice

Science Daily - Tue, 02/18/2020 - 09:47
A 784,000 year climate simulation suggests that Southern Ocean sea ice significantly reduces deep ocean ventilation to the atmosphere during glacial periods by reducing both atmospheric exposure of surface waters and vertical mixing of deep ocean waters; in a global carbon cycle model, these effects led to a 40 ppm reduction in atmospheric CO2 during glacial periods relative to pre-industrial level, suggesting how sea ice can drive carbon sequestration early within a glacial cycle.

Mediterranean rainfall immediately affected by greenhouse gas changes

Science Daily - Mon, 02/17/2020 - 15:23
Mediterranean-type climates face immediate drops in rainfall when greenhouse gases rise, but this could be interrupted quickly if emissions are cut.

The Antarctica factor: Model uncertainties reveal upcoming sea level risk

Science Daily - Fri, 02/14/2020 - 07:49
Within this century already, due to Antarctica alone global sea level might rise up to three times as much as it did in the last century. This is a finding of an exceptionally comprehensive comparison of state-of-the-art computer models from around the world.

Polar bears in Baffin Bay skinnier, having fewer cubs due to less sea ice

Science Daily - Wed, 02/12/2020 - 09:30
Satellite tracking of adult females and visual monitoring of polar bears in Baffin Bay show changes from the 1990s to the period from 2009 to 2015. Bears in Baffin Bay are getting thinner and adult females are having fewer cubs than when sea ice was more available.

Ancient Antarctic ice melt increased sea levels by 3+ meters -- and it could happen again

Science Daily - Tue, 02/11/2020 - 15:48
Rising ocean temperatures drove the melting of Antarctic ice sheets and caused extreme sea level rise more than 100,000 years ago, a new international study l shows - and the scientists say we're headed in that direction again.

Climate change could trigger more landslides in High Mountain Asia

Science Daily - Tue, 02/11/2020 - 11:15
More frequent and intense rainfall events due to climate change could cause more landslides in the High Mountain Asia region of China, Tibet and Nepal, according to the first quantitative study of the link between precipitation and landslides in the region.

Coincidences influence the onset and ending of ice ages

Science Daily - Tue, 02/11/2020 - 09:38
An analysis of the so called climate spectrum shows why the ice ages have not behaved precisely as the models predict. A large element of coincidence is involved when an ice age begins or ends, the analysis shows. The results imply we should maybe use a more conservative risk assessment then the one IPCC recommends.

Himalayan glacier shows evidence of start of Industrial Revolution

Science Daily - Mon, 02/10/2020 - 14:33
Human beings altered one of the highest peaks in the Himalayas hundreds of years before a person ever set foot there, new research has found. The study indicates that the byproducts of burning coal in Europe in the late 18th century made their way to the Dasuopu glacier in the central Himalayas, some 6,400 miles as the crow flies from London, the birthplace of the Industrial Revolution.

Scientists show solar system processes control the carbon cycle throughout Earth's history

Science Daily - Mon, 02/10/2020 - 14:33
This new work sheds fresh light on the complicated interplay of factors affecting global climate and the carbon cycle -- and on what transpired millions of years ago to spark two of the most devastating extinction events in Earth's history.

Gulf coast mollusks rode out past periods of climate change

Science Daily - Mon, 02/10/2020 - 14:33
About 55 million years ago, a rapidly warming climate decimated marine communities around the world. But according to new research, it was a different story for snails, clams and other mollusks living in the shallow waters along what is now the Gulf Coast of the United States. They were able to survive.

Twist in the story of volcanism and mass extinctions

Science Daily - Mon, 02/10/2020 - 13:48
An emerging scientific consensus is that gases -- in particular carbon gases -- released by volcanic eruptions millions of years ago contributed to some of Earth's greatest mass extinctions. But new research suggests that that's not the entire story.

Arctic ice melt is changing ocean currents

Science Daily - Fri, 02/07/2020 - 08:57
Using 12 years of satellite data, NASA scientists have measured how the influx of cold, fresh water is affecting the Beaufort Gyre, a major Arctic current.

Trees in the Amazon are time capsules of human history, from culture to colonialism

Science Daily - Thu, 02/06/2020 - 10:06
The annals of human history have been recorded through text, art, and oral tradition. However, for hundreds of years tropical forests have also kept detailed records of the human activities that unfolded around them. Researchers now describe how the rings, physical chemistry, and DNA of living tropical trees reveal the impacts of native culture as well as the scars of colonial occupation.

Wasp nests used to date ancient Kimberley rock art

Science Daily - Thu, 02/06/2020 - 09:27
Mud wasp nests collected from Kimberley sites with the permission of traditional owners help scientists establish ancient art rock unique to the area is 12,000 years old not 17,000 years old.

Ocean temperatures impact Central American climate more than once thought

Science Daily - Wed, 02/05/2020 - 12:22
Researchers examined the rainfall history of Central America over the last 11,000 years. The results provide context for the development of tropical rainforest ecosystems in the region, and long-sought answers to what has been controlling rainfall in Central America for several millennia.

Scientists listen to whales, walruses and seals in a changing Arctic seascape

Science Daily - Mon, 02/03/2020 - 14:12
A year-round acoustic study of marine mammals in the northern Bering Sea is providing scientists with a valuable snapshot of an Arctic world already under drastic pressure from climate change.

Arctic permafrost thaw plays greater role in climate change than previously estimated

Science Daily - Mon, 02/03/2020 - 14:11
Abrupt thawing of permafrost will double previous estimates of potential carbon emissions from permafrost thaw in the Arctic, and is already rapidly changing the landscape and ecology of the circumpolar north, a new study finds.


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