Science Daily

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.

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 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.

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.

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.

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.

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.

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'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.

A fascinating new academic study suggests that peoples’ political orientation affects their perceptions and knowledge regarding basic facts about the North and South Poles.

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 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.

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.

To some scientists studying climate change, boreal peatlands are considered a potential ticking time bomb. With huge stores of carbon in peat, the fear is that rising global temperatures could cause the release of massive amounts of CO2 from the peatlands into the atmosphere -- essentially creating a greenhouse gas feedback loop. A new study challenges that notion.

Thirty-year weather records from 79 locations across Australia reveal peak downpours during storms are intensifying at warmer temperatures across all climate zones, leading to greater flash flood risks in cities.

Contrary to expectations, weathering rates over the past two million years have remained constant through glacial cycles, new research shows. Scientists are interested in the rates of these chemical weathering processes because they have big implications for the planet's carbon cycle, which shuttles carbon dioxide between land, sea, and air and influences global temperatures.

A new record of past climate change shows that a warm climate in northern Europe can be hit by a sudden cooling associated with an interruption of the North Atlantic Ocean circulation and the Gulf Stream. This study investigates the development of northern European climate about 120 thousand years ago.

Operation IceBridge wrapped up its seventh Arctic deployment on May 21, when NASA's C-130 research aircraft with the mission's researchers and instruments on board departed Thule Air Base in Greenland and headed to NASA's Wallops Flight Facility in Virginia.

Each summer, Greenland's ice sheet -- the world's second-largest expanse of ice, measuring three times the size of Texas -- begins to melt. Pockets of melting ice form hundreds of large, 'supraglacial' lakes on the surface of the ice. Many of these lakes drain through cracks and crevasses in the ice sheet, creating a liquid layer over which massive chunks of ice can slide. This natural conveyor belt can speed ice toward the coast, where it eventually falls off into the sea. Now researchers have found that while warming temperatures are creating more inland lakes, these lakes cannot drain their water locally, as lakes along the coast do, and are not likely to change the amount of water reaching the ground in inland regions.

In 2008 scientists documented for the first time how the icy bottoms of lakes atop the Greenland Ice Sheet can crack open suddenly -- draining the lakes completely within hours and sending torrents of water to the base of the ice sheet thousands of feet below. Now they have found a surprising mechanism that triggers the cracks.