Is the fate of the polar bear really doomed?

With global warming and melting ice, it isn’t easy being a polar bear anymore. Some studies have predicted that polar bears could very well be extinct by the end of the century. The good news is not all researchers think the bears are absolutely doomed. Scientists at the American Museum of Natural History (AMNH) have published a new paper indicating that things might not be as bleak for polar bears as their peers expect.

MIT study shows climate change mitigation potential of geoengineering the oceans

Like the leaves of New England maples, phytoplankton, the microalgae at the base of most oceanic food webs, photosynthesize when exposed to sunlight. In the process, they absorb carbon dioxide from the atmosphere, converting it to carbohydrates and oxygen. Many phytoplankton species also release dimethyl sulfide (DMS) into the atmosphere, where it forms sulfate aerosols, which can directly reflect sunlight or increase cloud cover and reflectivity, resulting in a cooling effect. The ability of phytoplankton to draw planet-warming carbon dioxide (CO2) from the atmosphere and produce aerosols that promote further cooling has made ocean fertilization — through massive dispersal of iron sulfite and other nutrients that stimulate phytoplankton growth — an attractive geoengineering method to reduce global warming.

The long-term effects of the Exxon Valdez oil spill

For 25 years, methodical research by scientists has investigated the effects of the Exxon Valdez oil spill in 1989 on Alaskan communities and ecosystems. A new study released today into the effects of the 1989 Exxon Valdez oil spill in Alaska shows that embryonic salmon and herring exposed to very low levels of crude oil can develop hidden heart defects that compromise their later survival, indicating that the spill may have had much greater impacts on spawning fish than previously recognized.

The herring population crashed four years after the spill in Prince William Sound and pink salmon stocks also declined, but the link to the oil spill has remained controversial. The new findings published in the online journal Scientific Reports suggest that the delayed effects of the spill may have been important contributors to the declines.

Ice sheets may be more resilient than previously thought

Sea level rise poses one of the biggest threats to human systems in a globally warming world, potentially causing trillions of dollars' worth of damages to flooded cities around the world. As surface temperatures rise, ice sheets are melting at record rates and sea levels are rising.

But there may be some good news amid the worry. Sea levels may not rise as high as assumed.

Farm air may prevent asthma in children

For researchers trying to untangle the roots of the current epidemic of asthma, one observation is especially intriguing: Children who grow up on dairy farms are much less likely than the average child to develop the respiratory disease. Now, a European team studying mice has homed in on a possible explanation: Bits of bacteria found in farm dust trigger an inflammatory response in the animals’ lungs that later protects them from asthma. An enzyme involved in this defense is sometimes disabled in people with asthma, suggesting that treatments inspired by this molecule could ward off the condition in people.

Hummingbirds and Hawks, perfect together?

Sometimes it pays to have big, bad neighbors. Weighing in at about 3 grams, black-chinned hummingbirds (Archilochus alexandri) can do little but stand by and watch Mexican jays 40 times their weight chow down on their eggs. So in the mountains of southeastern Arizona, the hummers have learned to build their nests near goshawk and Cooper’s hawk nests (Accipiter gentilis and Accipiter cooperii). Almost five times bigger than the jays (Amphelocoma wollweberi), the hawks enjoy these birds for lunch. So to avoid hawks swooping down and surprising them, the jays only forage above the hawks’ nests. Thus a cone-shaped safe zone exists below the 20-meter-high hawk nests, extending out about 100 meters, researchers report today in Science Advances. Of 342 hummer nests studied over three years, 80% were near hawk nests—and for good reason.

Coastal management strategies in the age of climate change

Coastal decision-makers must move away from considering physical and economic forces in isolation to fully recognise and explain changes to coastlines, according to new research from Cardiff University.

The coastlines where we live, work and play have long been altered by people, but now researchers have investigated why developed coastlines change over time in ways that are fundamentally different from their undeveloped, natural counterparts.
 

Fighting explosives pollution with plants

Biologists at the University of York have taken an important step in making it possible to clean millions of hectares of land contaminated by explosives.

Trees improve pollution dispersion in cities

Trees in cities throughout the UK could be significantly improving the quality of the air we breathe by decreasing pollution levels for pedestrians, researchers from the University of Leicester have revealed.

Climate change mitigation needs more ambitious emissions reductions

The collective climate targets submitted by Governments to the UN will lead to global emissions far above the levels needed to hold warming to below 2°C, researchers at the Climate Action Tracker warned today.

The analysis by the consortium of four research organisations was released today in Bonn where Governments are meeting for the second to last week of negotiations ahead of the Paris summit on climate action.