Science Daily

The polar bear, one of the largest carnivorous mammals on Earth, is being made vulnerable by the series of dangers it faces. An international team has established a guide to evaluate the condition of its health and although the polar bear's biggest threat is climate change, plastic pollution and environmental contaminants in its habitat are starting to affect its endocrine system and reproduction. Climate change is undoubtedly the main threat to polar bears. They also suffer from nutritional stress, reduction of polar ice, human contact and diseases and parasites. But that's not all, researchers warn.

Seventy percent of glacier ice in British Columbia and Alberta could disappear by the end of the 21st century, creating major problems for local ecosystems, power supplies, and water quality, according to a new study.

Polar bears, increasingly forced on shore due to sea ice loss, may be eating terrestrial foods including berries, birds and eggs, but any nutritional gains are limited to a few individuals and likely cannot compensate for lost opportunities to consume their traditional, lipid-rich prey -- ice seals.

The volcanologist Stephen Self, an expert on super-eruptions, was the first modern-day scientist to visit Tambora in Indonesia, the site of the largest volcanic eruption in 1,000 years. On the 200th anniversary of its eruption in 1815, Self and others warn of the ever-present dangers of volcanoes like Tambora. Globally dispersed clouds of sulfate aerosols could lead to cooling, crop failures and famine, as happened in the 'year without a summer' of 1816.

A new study reports that marine ecosystems can take thousands, rather than hundreds, of years to recover from climate-related upheavals. The study's authors analyzed thousands of invertebrate fossils to show that ecosystem recovery from climate change and seawater deoxygenation might take place on a millennial scale.

A new study has confirmed the existence of a positive feedback operating in climate change whereby warming itself may amplify a rise in greenhouse gases resulting in additional warming.

Cores of marine sediment reveal an earthquake history of the Cinarcik Segment, a main branch of NAF, and suggest a seismic gap where the next earthquake is likely to rupture, as detailed in a new study.

New research into the changing ecology of thousands of shallow lakes on the North Slope of Alaska suggests that in scenarios of increasing global temperatures, methane-generating microbes, found in thawing lake sediments, may ramp up production of the potent greenhouse gas -- which has a global warming potential 25 times greater than carbon dioxide.

Particles emitted during major volcanic eruptions cool the atmosphere due to a 'parasol' effect that reflects sunlight. The direct impact of these particles in the atmosphere is fairly short, lasting two to three years. However, they alter for more than 20 years the North Atlantic Ocean circulation, which connects surface and deep currents and influences the climate in Europe.

Cold snaps like the ones that hit the eastern United States in the past winters are not a consequence of climate change. Scientists have now shown that global warming actually tends to reduce temperature variability.

The official global target of a two degree Celsius temperature rise is 'utterly inadequate' for protecting those at most risk from climate change, says an expert. The commentary presents a rare inside-view of a discussion at the Lima Conference of the Parties on the likely consequences of accepting an average global warming target of 2 degrees Celsius versus 1.5 degrees Celsius.

A new study has revealed that the thickness of Antarctica's floating ice shelves has recently decreased by as much as 18 percent in certain areas over nearly two decades, providing new insights on how the Antarctic ice sheet is responding to climate change.

A team of researcher has used mathematical modeling to show that continental erosion over the last 40 million years has contributed to the success of diatoms, a group of tiny marine algae that plays a key role in the global carbon cycle.

The Atlantic overturning is one of Earth's most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe. Scientists now found evidence for a slowdown of the overturning -- multiple lines of observation suggest that in recent decades, the current system has been weaker than ever before in the last century, or even in the last millennium.

Society should set a high carbon tax now to try and prevent climate change reaching a point of no return according to a new study. The study shows that the prospect of an uncertain future tipping point should greatly increase the amount we are willing to pay now to limit climate change.

A new international study casts doubt on the leading theory of what causes ice ages around the world -- changes in the way the Earth orbits the sun. The researchers found that glacier movement in the Southern Hemisphere is influenced primarily by sea surface temperature and atmospheric carbon dioxide rather than changes in the Earth's orbit, which are thought to drive the advance and retreat of ice sheets in the Northern Hemisphere.

Incessant mountain rain, snow and melting glaciers in a comparatively small region of land that hugs the southern Alaska coast and empties fresh water into the Gulf of Alaska would create the sixth largest coastal river in the world if it emerged as a single stream, a recent study shows. Freshwater runoff of this magnitude may play important ecological roles.

There are a variety of proposals that involve using vertical ocean pipes to move seawater to the surface from the depths in order to reap different potential climate benefits. One idea involves using ocean pipes to facilitate direct physical cooling of the surface ocean by replacing warm surface ocean waters with colder, deeper waters. New research shows that these pipes could actually increase global warming quite drastically.

Many people in the UK feel a strong sense of regional identity, and it now appears that there may be a scientific basis to this feeling, according to a landmark new study into the genetic makeup of the British Isles.

A multinational team surveys the status of all Arctic marine mammals, including whales, walruses, seals and polar bears. The report is a first effort to assess the status of 78 subpopulations and recommend measures to protect these species under climate change.