In hot water: Climate change is affecting North American fish
June 30, 2016 04:54 PM - US Geological Survey via EurekAlert!
Climate change is already affecting inland fish across North America -- including some fish that are popular with anglers. Scientists are seeing a variety of changes in how inland fish reproduce, grow and where they can live, according to four new studies published today in a special issue of Fisheries magazine.
Fish that have the most documented risk include those living in arid environments and coldwater species such as sockeye salmon, lake trout, walleye, and prey fish that larger species depend on for food.
Climate change can cause suboptimal habitat for some fish; warmer water, for example, can stress coldwater fish. When stressed, fish tend to eat less and grow less. For other fish, climate change is creating more suitable habitat; smallmouth bass populations, for example, are expanding.
Ocean circulation implicated in past abrupt climate changes
June 30, 2016 04:25 PM - The Earth Institute at Columbia University via EurekAlert!
There was a period during the last ice age when temperatures in the Northern Hemisphere went on a rollercoaster ride, plummeting and then rising again every 1,500 years or so. Those abrupt climate changes wreaked havoc on ecosystems, but their cause has been something of a mystery. New evidence published this week in the leading journal Science shows for the first time that the ocean's overturning circulation slowed during every one of those temperature plunges - at times almost stopping.
"People have long supposed this link between overturning circulation and these abrupt climate events. This evidence implicates the ocean," said L. Gene Henry, the lead author of the study and a graduate student at Columbia University's Lamont-Doherty Earth Observatory.
Scientists observe first signs of healing in the Antarctic ozone layer
June 30, 2016 03:47 PM - Massachusetts Institute of Technology via EurekAlert!
Scientists at MIT and elsewhere have identified the "first fingerprints of healing" of the Antarctic ozone layer, published today in the journal Science.
The team found that the September ozone hole has shrunk by more than 4 million square kilometers -- about half the area of the contiguous United States -- since 2000, when ozone depletion was at its peak. The team also showed for the first time that this recovery has slowed somewhat at times, due to the effects of volcanic eruptions from year to year. Overall, however, the ozone hole appears to be on a healing path.
The authors used "fingerprints" of the ozone changes with season and altitude to attribute the ozone's recovery to the continuing decline of atmospheric chlorine originating from chlorofluorocarbons (CFCs). These chemical compounds were once emitted by dry cleaning processes, old refrigerators, and aerosols such as hairspray. In 1987, virtually every country in the world signed on to the Montreal Protocol in a concerted effort to ban the use of CFCs and repair the ozone hole.
Ocean acidification affects predator-prey response
June 29, 2016 05:25 PM - University of California - Davis via EurekAlert!
Ocean acidification makes it harder for sea snails to escape from their sea star predators, according to a study from the University of California, Davis.
The findings, published in the journal Proceedings of The Royal Society B, suggest that by disturbing predator-prey interactions, ocean acidification could spur cascading consequences for food web systems in shoreline ecosystems.
For instance, black turban snails graze on algae. If more snails are eaten by predators, algae densities could increase.
"Ocean acidification can affect individual marine organisms along the Pacific coast, by changing the chemistry of the seawater," said lead author Brittany Jellison, a Ph.D. student studying marine ecology at the UC Davis Bodega Marine Laboratory.
Crucial peatlands carbon-sink vulnerable to rising sea levels
June 29, 2016 05:06 PM - University of Exeter via EurekAlert!
Rising sea-levels linked to global warming could pose a significant threat to the effectiveness of the world's peatland areas as carbon sinks, a new study has shown.
The pioneering new study, carried out by Geographers at the University of Exeter, examined the impact that salt found in sea water has on how successfully peatland ecosystems accumulate carbon from the atmosphere.
The researchers studied an area of blanket bog - a peat bog that forms in cool regions susceptible to high rainfall - at Kentra Moss, in Northwest Scotland.
Floating Solar: A Win-Win for Drought-Stricken Lakes in U.S.
June 29, 2016 09:17 AM - Philip Warburg via Yale Environment360
The Colorado River’s two great reservoirs, Lake Mead and Lake Powell, are in retreat. Multi-year droughts and chronic overuse have taken their toll, to be sure, but vast quantities of water are also lost to evaporation. What if the same scorching sun that causes so much of this water loss were harnessed for electric power?
Installing floating solar photovoltaic arrays, sometimes called “floatovoltaics,” on a portion of these two reservoirs in the southwestern United States could produce clean, renewable energy while shielding significant expandes of water from the hot desert sun.
Pipelines affect health, fitness of salmon, study finds
June 28, 2016 02:26 PM - University of Guelph via EurekAlert!
Pipelines carrying crude oil to ports in British Columbia may spell bad news for salmon, according to a new University of Guelph-led study.
Exposure to an oil sands product - diluted bitumen - impairs the swimming ability and changes the heart structures of young salmon.
The research will be published in the journal Environmental Toxicology and Chemistry, and is available online now.
It's a timely finding, says U of G post-doctoral researcher and lead author Sarah Alderman.
The National Energy Board (NEB) recently approved the controversial Trans Mountain pipeline expansion project; the federal government is expected to make a final decision by December.
Climate Change Is Happening Faster Than African Crops Can Handle It
June 28, 2016 11:20 AM - Susan Bird, Care2
Crop yields in Africa will nosedive ten years from now unless we can develop varieties that can better deal with climate change. Unfortunately, we’re not breeding those hardier varieties fast enough.
That’s the sobering conclusion of a study published in the journal Nature Climate Change by researchers from the University of Leeds. As temperatures rise, crop yields fall. This is particularly true for staple crops like corn, bananas and beans raised in hot tropical areas.
Wind-blown Antarctic sea ice helps drive ocean circulation
June 27, 2016 11:34 AM - The Earth Institute at Columbia University via EurekAlert!
Antarctic sea ice is constantly on the move as powerful winds blow it away from the coast and out toward the open ocean. A new study shows how that ice migration may be more important for the global ocean circulation than anyone realized.
A team of scientists used a computer model to synthesize millions of ocean and ice observations collected over six years near Antarctica, and estimated, for the first time, the influence of sea ice, glacier ice, precipitation and heating on ocean overturning circulation. Overturning circulation brings deep water and nutrients up to the surface, carries surface water down, and distributes heat and helps store carbon dioxide as it flows through the world's oceans, making it an important force in the global climate system. The scientists found that freshwater played the most powerful role in changing water density, which drives circulation, and that melting of wind-blown sea ice contributed 10 times more freshwater than melting of land-based glaciers did.
Warning from the past: Future global warming could be even warmer
June 24, 2016 07:05 AM - Niels Bohr Institute
Future global warming will not only depend on the amount of emissions from man-made greenhouse gasses, but will also depend on the sensitivity of the climate system and response to feedback mechanisms. By reconstructing past global warming and the carbon cycle on Earth 56 million years ago, researchers from the Niels Bohr Institute among others have used computer modelling to calculate the potential perspective for future global warming, which could be even warmer than previously thought. The results are published in the scientific journal, Geophysical Research Letters.