Science Daily

The volume of Arctic sea ice increased by a third after the summer of 2013 as the unusually cool air temperatures prevented the ice from melting, according to scientists. This suggests that the ice pack in the Northern hemisphere is more sensitive to changes in summer melting than it is to winter cooling, a finding which will help researchers to predict future changes in its volume.

In 2014, the most essential indicators of Earth's changing climate continued to reflect trends of a warming planet, with several markers such as rising land and ocean temperature, sea levels and greenhouse gases -- setting new records. These key findings and others can be found in the State of the Climate in 2014 report released online by the American Meteorological Society (AMS).

Some earlier research suggested that polar bears could, at least partially, compensate for longer summer food deprivation by entering a state of lowered activity and reduced metabolic rate similar to winter hibernation -- a so-called 'walking hibernation.' But new research shows that the summer activity and body temperature of bears on shore and on ice were typical of fasting, non-hibernating mammals, with little indication of 'walking hibernation.'

The sun's activity could be affecting a key ocean circulation mechanism that plays an important role in regulating Greenland's climate, according to a new study. The phenomenon could be partially responsible for cool temperatures the island experienced in the late 20th century and potentially lead to increased melting of the Greenland ice sheet in the coming decades, the new research suggests.

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.

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.

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.

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.

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. 

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.

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 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.