Climate

Ice algae: The engine of life in the central Arctic Ocean
July 12, 2016 10:35 AM - Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research via EurekAlert!

Algae that live in and under the sea ice play a much greater role for the Arctic food web than previously assumed. In a new study, biologists of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) showed that not only animals that live directly under the ice thrive on carbon produced by so-called ice algae. Even species that mostly live at greater depth depend to a large extent on carbon from these algae. This also means that the decline of the Arctic sea ice may have far-reaching consequences for the entire food web of the Arctic Ocean. Their results have been published online now in the journal Limnology & Oceanography.

The summer sea ice in the Arctic is diminishing at a rapid pace and with it the habitat of ice algae. The consequences of this decline for the Arctic ecosystem are difficult to predict. Scientists of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research showed the significance of ice algae for the Arctic food web in this context. "A number of studies have already speculated that ice algae are an important energy source for the polar ecosystems. We have now been able to show that not only animals associated with ice meet the majority of their carbon needs from ice algae, but that, surprisingly, so do species that mostly live at greater depths," says lead author Doreen Kohlbach.

Climate change is apparently shifting clouds towards the poles
July 12, 2016 09:00 AM - NELL GREENFIELDBOYCE, NPR

The way clouds cover the Earth may be changing because of global warming, according to a study published Monday that used satellite data to track cloud patterns across about two decades, starting in the 1980s.

Clouds in the mid-latitudes shifted toward the poles during that period, as the subtropical dry zones expanded and the highest cloud-tops got higher.

These changes are predicted by most climate models of global warming, even though those models disagree on a lot of other things related to clouds, says Joel Norris, a climate scientist at the University of California, San Diego.

 

Regulating particulate pollution
July 12, 2016 07:16 AM - Nancy W. Stauffer, MIT Energy Initiative

An MIT analysis of how best to reduce fine particulate matter in the atmosphere has brought some surprising results. Due to past regulations, levels of key emissions that form those harmful particles are now lower than they were a decade ago, causing some experts to suggest that cutting them further might have little effect. Not true, concludes the MIT study. Using an atmospheric model, the researchers found that new policies to restrict the same emissions would be even more effective now than they were in the past. Further analysis elucidated the chemical processes — some unexpected — that explain their findings. Their results demonstrate the importance of tailoring air pollution policies to specific situations and of addressing a variety of emissions in a coordinated way.

Climate change may shrink Adélie penguin range by end of century
July 8, 2016 05:04 PM - Nasa / Goddard Space Flight Center via EurekAlert!

Climate has influenced the distribution patterns of Adélie penguins across Antarctica for millions of years. The geologic record tells us that as glaciers expanded and covered Adélie breeding habitats with ice, penguins in the region abandoned their colonies. When the glaciers melted during warming periods, the Adélie penguins were able to return to their rocky breeding grounds.

Now, a NASA-funded study by University of Delaware scientists and colleagues at other institutions reports that this warming may no longer be beneficial for Adélie penguins. In a paper published June 29 in the journal Scientific Reports, the researchers project that approximately 30 percent of current Adélie colonies may be in decline by 2060, and approximately 60 percent of the present population might be dwindling by 2099. They also found the penguins at more southerly sites in Antarctica may be less affected by climate change.

Researchers assess heatwave risks associated with climate change
July 8, 2016 06:35 AM - IOP Publishing via EurekAlert!

Combining climate and mortality data, researchers have estimated that 315 deaths in Greater London and 735 deaths in Central Paris can be strongly linked to the 2003 heatwave that set record-breaking temperatures across Europe. Taking their analysis a step further, they determine that 64 (± 3) deaths from the London dataset and 506 (± 51) deaths from the Paris dataset are attributable to anthropogenic climate change, which increased the risk of heat related mortality by 20% and 70%, respectively, in the two cities. The team, led by scientists from the University of Oxford and Public Health England, has reported its latest findings in the journal Environmental Research Letters.

Frogs that can take the heat expected to fare better in a changing world
July 7, 2016 04:01 PM - University of California - Davis via EurekAlert!

Amphibians that tolerate higher temperatures are likely to fare better in a world affected by climate change, disease and habitat loss, according to two recent studies from the University of California, Davis.

Frogs are disappearing globally, and the studies examine why some survive while others perish. The studies reveal that thermal tolerance -- the ability to withstand higher temperatures -- may be a key trait in predicting amphibian declines.

HEAT-TOLERANT FROGS ESCAPE DEADLY FUNGUS

One of the world's deadliest wildlife pandemics is caused by a fungus, Batrachochytrium dendrobatidis, or Bd. The fungus is linked to several amphibian extinctions and global declines.

NASA's airborne mission to explore the global atmosphere
July 7, 2016 01:31 PM - Nasa/Goddard Space Flight Center via EurekAlert!

Ice sheets, deserts, rivers, islands, coasts and oceans -- the features of Earth's surface are wildly different, spread across a vast geography. The same is true for Earth's thin film of atmosphere and the mix of gases it holds, although the details are invisible to human eyes. Pollutants emitted to the atmosphere -- soot, hydrocarbons, nitrogen oxides -- are dispersed over the whole globe, but remote regions are cleaner, by factors of 1000 or more, than areas near the continents. A new NASA airborne campaign aims to map the contours of the atmosphere as carefully as explorers once traced the land and oceans below.

The Atmospheric Tomography, or ATom, mission is the first to survey the atmosphere over the oceans. Scientists aboard NASA's DC-8 flying laboratory will journey from the North Pole south over the Pacific Ocean to New Zealand and then across to the tip of South America and north up the Atlantic Ocean to Greenland. ATom will discover how much pollution survives to the most remote corners of the earth and assess how the environment has changed as a result.

Weathering of rocks by mosses may explain climate effects during the Late Ordovician
July 7, 2016 11:00 AM - Stockholm University via EurekAlert!

During the Ordovician period, the concentration of CO2 in the earth's atmosphere was about eight times higher than today. It has been hard to explain why the climate cooled and why the Ordovician glaciations took place. A new study, published in Nature Communications, shows that the weathering of rock caused by early non-vascular plants had the potential to cause such a global cooling effect.

"When we can better understand the carbon cycle in the past, we can better predict what happens with the climate in the future," says Philipp Porada of Stockholm University, one of the authors of the study.

'The Blob' overshadows El Nino
July 7, 2016 10:40 AM - NOAA Fisheries West Coast Region via ScienceDaily

New research based on ocean models and near real-time data from autonomous gliders indicates that the "The Blob" and El Niño together strongly depressed productivity off the West Coast, with The Blob driving most of the impact.

The research published in the journal Geophysical Research Letters by scientists from NOAA Fisheries, Scripps Institution of Oceanography and University of California, Santa Cruz is among the first to assess the marine effects of the 2015-2016 El Niño off the West Coast of the United States.

"Last year there was a lot of speculation about the consequences of 'The Blob' and El Niño battling it out of the U.S. West Coast," said lead author Michael Jacox, of UC Santa Cruz and NOAA Fisheries' Southwest Fisheries Science Center. "We found that off California El Niño turned out to be much weaker than expected, The Blob continued to be a dominant force, and the two of them together had strongly negative impacts on marine productivity."

The Antarctic Ozone Hole May Be Closing
July 7, 2016 07:21 AM - s.e. smith

There’s good news from Antarctica, where researchers with tools like ozonesondes — pictured above — have been following the infamous ozone hole as it waxes and wanes over the seasons. The ozone hole has shrunk by 1.5 million square miles – around 4 million square kilometers — and this “healing” trend appears to be continuing.

A major ecological catastrophe has been averted, and we can cite human intervention as the reason. When the globe swept into action with 1987′s Montreal Protocol, which banned a number of substances known to contribute to ozone depletion, it apparently worked.

When scientists first began to observe a hole in the ozone layer over Antarctica, it was a cause for grave concern. Though ozone levels actually fluctuate throughout the year, they perform an important function by blocking the sun’s harmful UV radiation.

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