Soils could release much more CO2 than expected into the atmosphere as the climate warms, according to new research by scientists from the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab).
Their findings are based on a field experiment that, for the first time, explored what happens to organic carbon trapped in soil when all soil layers are warmed, which in this case extend to a depth of 100 centimeters. The scientists discovered that warming both the surface and deeper soil layers at three experimental plots increased the plots’ annual release of CO2 by 34 to 37 percent over non-warmed soil. Much of the CO2 originated from deeper layers, indicating that deeper stores of carbon are more sensitive to warming than previously thought.
They report their work online March 9 in the journal Science.
— source newscenter.lbl.gov
Huge slabs of Arctic permafrost in northwest Canada are slumping and disintegrating, sending large amounts of carbon-rich mud and silt into streams and rivers. A new study that analyzed nearly a half-million square miles in northwest Canada found that this permafrost decay is affecting 52,000 square miles of that vast stretch of earth—an expanse the size of Alabama.
According to researchers with the Northwest Territories Geological Survey, the permafrost collapse is intensifying and causing landslides into rivers and lakes that can choke off life downstream, all the way to where the rivers discharge into the Arctic Ocean.
Permafrost is land that has been frozen stretching back to the last ice age, 10,000 years ago. As the Arctic warms at twice the global rate, the long-frozen soils thaw and decompose, releasing the trapped greenhouse gases into the air. Scientists estimate that the world’s permafrost holds twice as much carbon as the atmosphere.
— source insideclimatenews.org
For many years new hydropower dams were assumed to be zero greenhouse gas emitters. Now with 847 large (more than 100 MW) and 2,853 smaller (more than 1 MW) hydropower projects currently planned or under construction around the world, a new global study has shown that dam reservoirs are major greenhouse gas emitters.
The study looked at the carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emitted from 267 reservoirs across six continents. Globally, the researchers estimate that reservoirs contribute 1.3 percent of human-made greenhouse gas emissions, comparable to those from rice paddy cultivation or biomass burning.
Reservoir emissions are not currently counted within the UN Intergovernmental Panel on Climate Change (UN IPCC) emissions assessments, but they should be, argue the researchers. In fact, countries are currently eligible under the UN’s Clean Development Mechanism (CDM) to receive carbon credits for newly built dams.
The study raises the question as to whether hydropower should continue to be counted as green power or be eligible for UN CDM carbon credits.
— source news.mongabay.com
Researchers from 20 of the world’s leading oceanographic research centers today warned that the world’s largest habitat – the deep ocean floor – may face starvation and sweeping ecological change by the year 2100. Warming ocean temperatures, increased acidification and the spread of low-oxygen zones will drastically alter the biodiversity of the deep ocean floor from 200 to 6,000 meters below the surface. The impact of these ecosystems to society is just becoming appreciated, yet these environments and their role in the functioning of the planet may be altered by these sweeping impacts. Results of the study, which was supported by the Foundation Total and other organizations, were published this week in the journal Elementa.
— source phys.org
The Pine Island Glacier on the coast of West Antarctica is a case in point. A massive iceberg roughly 225 square miles in size — or in more familiar terms, 10 times the size of Manhattan — broke off in July 2015. Scientists subsequently spotted cracks in the glacier on a November 2016 flyover. And in January, another iceberg cleaved off the glacier.
The ocean under Pine Island Glacier’s ice shelf has warmed about 1°F since the 1990s. That’s causing the ice shelf to melt and pushing the grounding line — the point where the ice begins to float — back toward land, creating further instability.
— source climatecentral.org
Thwaites Glacier on the edge of West Antarctica is one of the planet’s fastest-moving glaciers. Research shows that it is sliding unstoppably into the ocean, mainly due to warmer seawater lapping at its underside.
Researchers at the University of Washington and the University of Edinburgh used data from the European Space Agency’s CryoSat-2 to identify a sudden drainage of large pools below Thwaites Glacier, one of two fast-moving glaciers at the edge of the ice sheet. The study published Feb. 8 in The Cryosphere finds four interconnected lakes drained in the eight months from June 2013 and January 2014. The glacier sped up by about 10 percent during that time, showing that the glacier’s long-term movement is fairly oblivious to trickles at its underside.
— source washington.edu
Marking another milestone for a changing planet, scientists reported on Wednesday that the Earth reached its highest temperature on record in 2016, trouncing a record set only a year earlier, which beat one set in 2014. It is the first time in the modern era of global warming data that temperatures have blown past the previous record three years in a row.
— source nytimes.com