Detecting forest fragility with satellites
September 6, 2016 08:48 AM - Wageningen University and Research Centre via ScienceDaily
Over the past decades’ forests in different parts of the world have suffered sudden massive tree mortality. Now an international team of scientists led by researchers from Wageningen University in the Netherlands has found a way to spot from satellite images which forests may be most likely to fall prey to such die-off events.
Clues in ancient mud hold answers to climate change
September 2, 2016 02:51 PM - University of Notre Dame via ScienceDaily
New research suggests that Africa has gradually become wetter over the past 1.3 million years -- instead of drier as was thought previously.
The research from Berke, assistant professor in the Department of Civil and Environmental Engineering and Earth Sciences at the University of Notre Dame and Environmental Change Initiative affiliate, suggests that Africa has gradually become wetter over the past 1.3 million years -- instead of drier as was thought previously. The findings shine new light on the "savanna hypothesis," which held that humans in Africa as a whole migrated to grasslands due to a changing climate.
The sediment samples that Berke studied came from Lake Malawi in southeast Africa, whereas data used for the savanna hypothesis came from the north. Her research suggests that climate conditions across Africa may have been more variable than once thought.
Subantarctic seabed creatures shed new light on past climate
September 1, 2016 04:59 PM - British Antarctic Survey via EurekAlert!
A new marine biodiversity study in one of the largest Marine Protected Areas in the world reveals the impact of environmental change on subantarctic seabed animals and answers big questions about the extent of South Georgia's ice sheet during the Last Glacial Maximum around 20,000 years ago.
Reporting this week in the Journal of Biogeography researchers at British Antarctic Survey (BAS) describe how colonies of seabed creatures, such as sea sponges - that play an important role in absorbing and storing carbon from the atmosphere - can take thousands of years to recover from major glaciation events.
Sediments control methane release to the ocean
August 31, 2016 04:12 PM - University of Tromso via ScienceDaily
Methane is stored under the sea floor, concentrated in form of hydrates, crystalline ice structures that stay stable under high pressure and in low temperatures. Several studies suggest that as the ocean warms, the hydrates might melt and potentially release methane into the ocean waters and atmosphere.
Several studies suggest that as the ocean warms, the hydrates might melt and potentially release methane into the ocean waters and atmosphere. This potent climate gas is profusely leaking from the seafloor in an area offshore western Svalbard, which is close to the gas hydrate stability zone.
There, scientists have discovered over 250 methane flares in water depths from 90 to 240 meters.
“Previous studies indicate that these seeps could be linked to gas hydrate dissociations. We suspected that dissociation of gas hydrate is not the primary control on seafloor methane seepage. We suggest that there is a strong lithological control on methane seepage.” says Dr. Giuliana Panieri, scientist at CAGE.
Climate change has less impact on drought than previously expected
August 31, 2016 03:47 PM - University of California – Irvine via ScienceDaily
As a multiyear drought grinds on in the Southwestern United States, many wonder about the impact of global climate change on more frequent and longer dry spells. As humans emit more carbon dioxide into the atmosphere, how will water supply for people, farms, and forests be affected?
A new study from the University of California, Irvine and the University of Washington shows that water conserved by plants under high CO2 conditions compensates for much of the effect of warmer temperatures, retaining more water on land than predicted in commonly used drought assessments.
According to the study published this week in the Proceedings of the National Academy of Sciences, the implications of plants needing less water with more CO2 in the environment changes assumptions of climate change impacts on agriculture, water resources, wildfire risk, and plant growth.
Study assesses climate change vulnerability in urban America
August 31, 2016 07:17 AM - George Washington University via EurekAlert!
Flooding due to rising ocean levels. Debilitating heat waves that last longer and occur more frequently. Rising rates of diseases caused by ticks, fleas, and mosquitoes, such as Lyme disease, Chikungunya, and Zika. Increasing numbers of Emergency Room visits for asthma attacks due to higher levels of ground-level ozone. Impacts of climate change such as these will affect cities across the country.
One of the first efforts to systematically assess how cities are preparing for climate change shows that city planners have yet to fully assess their vulnerability to climate change, leaving serious risks unaddressed. In their evaluations to-date, they see infrastructure and risks to specific human populations as the primary areas of concern. Despite these concerns, expert assessments of urban climate vulnerability often do not address the real risks that local planners face.
August 30, 2016 04:59 PM - University of California - Santa Barbara via EurekAlert!
In California's Sierra Nevada mountains, as more precipitation falls in the form of rain rather than snow, and the snowpack melts earlier in spring, it's important for water managers to know when and how much water will be available for urban and agricultural needs and for the environment in general.
While changing precipitation patterns can have a significant impact on stream flows in the Sierra Nevada mountains, a new study by UC Santa Barbara researchers indicates that shifts in vegetation type resulting from warming and other factors may have an equal or greater effect. Their findings appear in the journal PLOS One.
Obama Creates the World's Largest Marine Reserve
August 30, 2016 07:12 AM - Steve Williams, Care2
The Papahānaumokuākea Marine National Monument, first named a national monument by President George W. Bush in 2006, is a massively important marine nature reserve.
Designated a World Heritage site, the region surrounding the Northwestern Hawaiian Islands teems with more than 7,000 marine and land species — some of which are unique to the area, including endangered whales and sea turtles. As a result, the region has been deemed irreplaceable by scientists.
Study finds shark fins & meat contain high levels of neurotoxins linked to Alzheimer's disease
August 29, 2016 04:45 PM - University of Miami Rosenstiel School via EurekAlert!
In a new study, University of Miami (UM) scientists found high concentrations of toxins linked to neurodegenerative diseases in the fins and muscles of 10 species of sharks. The research team suggests that restricting consumption of sharks can have positive health benefits for consumers and for shark conservation, since several of the sharks analyzed in the study are threatened with extinction due to overfishing.
Fins and muscle tissue samples were collected from 10 shark species found in the Atlantic and Pacific Oceans for concentrations of two toxins--mercury and β-N-methylamino-L-alanine (BMAA). "Recent studies have linked BMAA to neurodegenerative diseases such as Alzheimer's disease and amyotrophic lateral sclerosis (ALS)," said Deborah Mash, Professor of Neurology and senior author of the study.
The Sound of a Healthy Reef
August 29, 2016 03:18 PM - Woods Hole Oceanographic Institution
A new study from the Woods Hole Oceanographic Institution (WHOI) will help researchers understand the ways that marine animal larvae use sound as a cue to settle on coral reefs. The study, published on August 23rd in the online journal Scientific Reports, has determined that sounds created by adult fish and invertebrates may not travel far enough for larvae —which hatch in open ocean—to hear them, meaning that the larvae might rely on other means to home in on a reef system.