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Fossils indicate human activities have disturbed ecosystem resilience

Science Daily - Mon, 07/13/2015 - 15:14
A collection of fossilized owl pellets in Utah suggests that when the Earth went through a period of rapid warming about 13,000 years ago, the small mammal community was stable, even as individual species changed along with the habitat and landscape. By contrast, human-caused changes to the environment since the late 1800s have caused an enormous drop in biomass and 'energy flow' in this same community. The resilience that these lands once had to environmental change is being lost.

Rainfall drives rapid melt, flow of the Greenland ice sheet

Science Daily - Mon, 07/13/2015 - 10:34
The Greenland ice sheet has been shown to accelerate in response to surface rainfall and melt associated with late-summer and autumnal cyclonic weather events, new research shows.

Surprisingly high geothermal heating beneath West Antarctic Ice Sheet

Science Daily - Fri, 07/10/2015 - 15:09
The amount of heat flowing toward the base of the West Antarctic ice sheet from geothermal sources deep within the Earth is surprisingly high, according to a new study. The results provide important data for researchers trying to predict the fate of the ice sheet, which has experienced rapid melting over the past decade.

Global sea levels have risen six meters or more with just slight global warming

Science Daily - Thu, 07/09/2015 - 13:51
A new review analyzing three decades of research on the historic effects of melting polar ice sheets found that global sea levels have risen at least six meters, or about 20 feet, above present levels on multiple occasions over the past three million years. What is most concerning is that amount of melting was caused by an increase of only 1-2 degrees (Celsius) in global mean temperatures.

Solar activity predicted to fall 60% in 2030s, to 'mini ice age' levels: Sun driven by double dynamo

Science Daily - Thu, 07/09/2015 - 08:29
A new model of the Sun's solar cycle is producing unprecedentedly accurate predictions of irregularities within the Sun's 11-year heartbeat. The model draws on dynamo effects in two layers of the Sun, one close to the surface and one deep within its convection zone. Predictions from the model suggest that solar activity will fall by 60 per cent during the 2030s to conditions last seen during the 'mini ice age' that began in 1645. 

Volcanic eruptions that changed human history

Science Daily - Wed, 07/08/2015 - 12:38
It is well known that large volcanic eruptions contribute to climate variability. A new study uses new evidence found in both ice cores and corresponding tree rings to show the timing and associated radiative forcing of nearly 300 individual volcanic eruptions extending as far back as the early Roman period.

Risk of interbreeding due to climate change lower than expected

Science Daily - Mon, 07/06/2015 - 10:41
A surprising study of North and South American mammals, birds and amphibians finds that only about 6 percent of closely related species whose ranges do not currently overlap are likely to come into contact by the end of this century.

Greenhouse gas emissions remain primary threat to polar bears

Science Daily - Fri, 07/03/2015 - 07:52
Greenhouse gas emissions remain the primary threat to the preservation of polar bear populations worldwide. This conclusion holds true under both a reduced greenhouse gas emission scenario that stabilizes climate warming and another scenario where emissions and warming continue at the current pace, according to updated research models.

Recent mercury pollution on the rise, but quick to change, study shows

Science Daily - Mon, 06/29/2015 - 13:21
A study using a 600-year-old ice core shows that global mercury pollution increased dramatically during the 20th century, but that mercury concentrations in the atmosphere decreased faster than previously thought beginning in the late 1970s when emissions started to decline.

Retreating sea ice linked to changes in ocean circulation, could affect European climate

Science Daily - Mon, 06/29/2015 - 11:34
Retreating sea ice in the Iceland and Greenland Seas may be changing the circulation of warm and cold water in the Atlantic Ocean, and could ultimately impact the climate in Europe, says a new study.

Iron: A biological element?

Science Daily - Fri, 06/26/2015 - 07:39
Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and a half billion years ago. That's the upshot of a new study. Its findings have meaning for fields as diverse as mining and the search for life in space.

Backward-moving glacier helps scientists explain glacial earthquakes

Science Daily - Thu, 06/25/2015 - 13:39
The relentless flow of a glacier may seem unstoppable, but a team of researchers from the United Kingdom and the U.S. has shown that during some calving events -- when an iceberg breaks off into the ocean -- the glacier moves rapidly backward and downward, causing the characteristic glacial earthquakes which until now have been poorly understood.

Sudden shift in 'forcing' led to demise of Laurentide ice sheet

Science Daily - Tue, 06/23/2015 - 09:36
The massive Laurentide ice sheet that covered Canada during the last ice age initially began shrinking through calving of icebergs, and then abruptly shifted into a new regime where melting on the continent took precedence, ultimately leading to the sheet's demise. This is important, because it may provide a clue to how ice sheets on Greenland and Antarctica may respond to a warming climate.

Jet contrails affect surface temperatures

Science Daily - Thu, 06/18/2015 - 11:22
High in the sky where the cirrus ice crystal clouds form, jet contrails draw their crisscross patterns. Now researchers have found that these elevated ice cloud trails can influence temperatures on the ground and affect local climate, according to a team of geographers.

Risk of major sea level rise in England, Northern Europe

Science Daily - Thu, 06/18/2015 - 09:38
Global warming leads to the ice sheets on land melting and flowing into the sea, which consequently rises. New calculations show that the sea level in Northern Europe may rise more than previously thought. There is a significant risk that the seas around Scandinavia, England, the Netherlands and northern Germany will rise by up to about 1.5 meters in this century.

Alaska glaciers make large contributions to global sea level rise

Science Daily - Wed, 06/17/2015 - 12:56
Alaska's melting glaciers are adding enough water to the Earth's oceans to cover the state of Alaska with a 1-foot thick layer of water every seven years, a new study shows.

Polarized public perceptions of the Polar regions revealed

Science Daily - Tue, 06/16/2015 - 09:21
A fascinating new academic study suggests that peoples’ political orientation affects their perceptions and knowledge regarding basic facts about the North and South Poles.

Polar bears aren't the only victims of climate change

Science Daily - Mon, 06/15/2015 - 12:29
From heat waves to damaged crops to asthma in children, climate change is a major public health concern, argues a researcher. Climate change is about more than melting ice caps and images of Earth on fire, he said, believing that bioethicists could help reframe current climate change discourse.

Variations in atmospheric oxygen levels shaped Earth's climate through the ages

Science Daily - Thu, 06/11/2015 - 13:42
Variations in the amount of oxygen in Earth's atmosphere significantly altered global climate throughout the planet's history. Efforts to reconstruct past climates must include this previously overlooked factor, a new study concludes.

Dramatic ice sheet collapse 135 thousand years ago triggered strong global climate change

Science Daily - Wed, 06/10/2015 - 12:14
The climatic events that ended the ice age before last are surprisingly different to those of the last ice age, an international team of scientists has found. These findings will help scientists understand the processes that control Earth's dramatic climate changes at the end of an ice age.

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