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Is a Sleeping Climate Giant Stirring in the Arctic?

Flying low and slow above the wild, pristine terrain of Alaska's North Slope in a specially instrumented NASA plane, research scientist Charles Miller of NASA's Jet Propulsion Laboratory, Pasadena, Calif., surveys the endless whiteness of tundra and frozen permafrost below. On the horizon, a long, dark line appears. The plane draws nearer, and the mysterious object reveals itself to be a massive herd of migrating caribou, stretching for miles. It's a sight Miller won't soon forget.
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Climate slowdown means extreme rates of warming 'not as likely'

Scientists say the recent downturn in the rate of global warming will lead to lower temperature rises in the short-term.
Since 1998, there has been an unexplained "standstill" in the heating of the Earth's atmosphere.
Writing in Nature Geoscience, the researchers say this will reduce predicted warming in the coming decades.
But long-term, the expected temperature rises will not alter significantly.

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Climate Change Future Suggested by Looking Back 4 Million Years

The last time the Earth enjoyed greenhouse gas levels like those of today was roughly 4 million years ago, during an era known as the Pliocene. The extra heat of average temperatures as much as 4 degrees Celsius warmer turned the tropical oceans into a nice warm pool of bathwater, as noted by new research published in Nature on April 4.
By analysing the ratio of magnesium and calcium in the shells of microscopic animals found in long cores of mud from the deep ocean, the researchers confirmed this massive oceanic warm pool. At about 28 degrees C, the surface sea temperatures were not much warmer than todays tropical oceans, but these warm waters covered much more of the global ocean surface.

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Warming 'seesaw' turns extra sunlight into global greenhouse

Earth's most recent shift to a warm climate began with intense summer sun in the Northern Hemisphere, the first pressure on a seesaw that tossed powerful forces between the planet's poles until greenhouse gases accelerated temperature change on a global scale. Climate scientists, led by a group from the University of Wisconsin-Madison, used computer models to provide the strongest support yet to a case made nearly 90 years ago by mathematician Milutin Milankovitch.
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Increases in extreme rainfall linked to global warming

A worldwide review of global rainfall data led by the University of Adelaide has found that the intensity of the most extreme rainfall events is increasing across the globe as temperatures rise.
In the most comprehensive review of changes to extreme rainfall ever undertaken, researchers evaluated the association between extreme rainfall and atmospheric temperatures at more than 8000 weather gauging stations around the world.
 
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Tiny fossils hold answers to big questions on climate change

The western Antarctic Peninsula is one of the fastest warming regions on the planet, and the fastest warming part of the Southern Hemisphere.
Scientists have debated the causes of this warming, particularly in light of recent instrumental records of both atmospheric and oceanic warming from the region. As the atmosphere and ocean warm, so the ice sheet (holding an equivalent of 5 metres of global sea level rise, locked up in ice) becomes vulnerable to collapse.
Now research led by Cardiff University published in Nature Geoscience (20 Jan 2013) has used a unique 12,000 year long record from microscopic marine algae fossils to trace glacial ice entering the ocean along the western Antarctic Peninsula.
The study has found that the atmosphere had a more significant impact on warming along the western Antarctic Peninsula than oceanic circulation in the late Holocene (from 3500-250 years ago).

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Climate model forecast is revised

The UK Met Office has revised one of its forecasts for how much the world may warm in the next few years.
It says that the average temperature is likely to rise by 0.43 C by 2017 - as opposed to an earlier forecast that suggested a warming of 0.54C.
The explanation is that a new kind of computer model using different parameters has been used.

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Earth May Be Warming Even Faster Than Expected

Scientists have thought that if planetary warming could be kept below a 2-degree Celsius increase, perils such as catastrophic sea-level rise and searing heat waves could be avoided.
Ongoing data, however, indicate that three global feedback mechanisms may be pushing Earth into a period of rapid climate change even before the 2-degree C "limit" is reached

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Snow cover hits record lows

Santa Claus may someday need wheels for his sleigh - satellites show a decreasing amount of snow in the Northern Hemisphere.
A new analysis of snow cover observed by satellites shows record lows in Eurasia for June each year since 2008. In addition, three of the past five years have seen record low cover in North America.

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Clearest evidence yet of polar ice losses

An international team of satellite experts has produced the most accurate assessment of ice losses from Antarctica and Greenland to date, ending 20 years of uncertainty.
In a landmark study, published on 30 November in the journal Science, the researchers show that melting of the Antarctic and Greenland ice sheets has contributed 11.1 millimetres to global sea levels since 1992. This amounts to one fifth of all sea level rise over the survey period.
About two thirds of the ice loss was from Greenland, and the remainder was from Antarctica.

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