DATE: April 25, 2017
SNIP: A slow-moving emergency is lapping at California’s shores— climate-driven sea-level rise that experts now predict could elevate the water in coastal areas up to 10 feet in just 70 years, gobbling up beachfront and overwhelming low-lying cities.
The speed with which polar ice is melting and glacier shelves are cracking off indicates to some scientists that once-unthinkable outer-range projections of sea rise may turn out to be too conservative. A knee-buckling new state-commissioned report warns that if nothing changes, California’s coastal waters will rise at a rate 30 to 40 times faster than in the last century.
The potential result: crippled economies, compromised public safety, submerged infrastructure, and a forced retreat from our iconic Pacific coast.
SOURCE: Climate Central
DATE: April 25, 2017
SNIP: Evidence continues to mount that climate change has pushed the Arctic into a new state. Skyrocketing temperatures are altering the essence of the region, melting ice on land and sea, driving more intense wildfires, altering ocean circulation and dissolving permafrost.
A new report chronicles all these changes and warns that even if the world manages to keep global warming below the targeted 2°C threshold, some of the shifts could be permanent. Among the most harrowing are the disappearance of sea ice by the 2030s and more land ice melt than previously thought, pushing seas to more extreme heights.
The findings, released Monday in the Snow, Water, Ice and Permafrost in the Arctic (SWIPA) assessment, come after a winter of extreme discontent for the region. Sea ice receded a bit in November, a rare occurrence, and hit a record-low maximum for the third year in a row. Temperatures averaged 11°F above normal, driven by sustained mild weather that was punctured by periods of almost unheard of heat when temperatures reached up to 50°F above normal.
DATE: April 24, 2017
SNIP: A new study indicates that the number of plant and animal species at risk of extinction may be considerably higher than previously thought. A team of researchers, however, believe they’ve come up with a formula that will help paint a more accurate picture.
The study appears in the journal Biological Conservation.
Currently, IUCN makes use of species sightings reported by experts to draw boundaries reflecting the geographic range of a given species. From these maps, the IUCN develops its Red List, which assigns a threat status to wild species: Vulnerable, Endangered, or Critically Endangered. Though the accuracy of threat risk assigned to a species relies heavily on these maps, Melnick and his colleagues believe they almost always overestimate the actual distribution of a species by incorporating areas of unsuitable habitat. This overestimation of range size, in turn, leads to a significant overestimation of population size and therefore an underestimation of extinction risk.
SOURCE: Washington Post
DATE: April 20, 2017
SNIP: U.S. government scientists have found a dramatic impact from the continuing decline of coral reefs: The seafloor around them is eroding and sinking, deepening coastal waters and exposing nearby communities to damaging waves that reefs used to weaken.
“We knew that coral reefs were degrading, but we didn’t really know how much until we did this study,” said USGS oceanographer Kimberly Yates, the lead study author. “We didn’t really realize until now that they’re degrading enough that it’s actually affecting the rest of the seafloor as well.”
“Erosion of coral reefs and seafloor is happening much more and much faster than what was previously known or expected, enough so that it’s affecting those local sea level rises,” said Yates. “Enough so that it increases the risk to the coastlines from coastal hazards, storm waves, every day persistent waves, tsunamis and those kinds of things.”
DATE: April 19, 2017
SNIP: In the first such continent-wide survey, scientists have found extensive drainages of meltwater flowing over parts of Antarctica’s ice during the brief summer. Researchers already knew such features existed, but assumed they were confined mainly to Antarctica’s fastest-warming, most northerly reaches. Many of the newly mapped drainages are not new, but the fact they exist at all is significant; they appear to proliferate with small upswings in temperature, so warming projected for this century could quickly magnify their influence on sea level. An accompanying study looks at how such systems might influence the great ice shelves ringing the continent, which some researchers fear could collapse, bringing catastrophic sea-level rises.
“This is not in the future—this is widespread now, and has been for decades,” said lead author Jonathan Kingslake, a glaciologist at Columbia University’s Lamont-Doherty Earth Observatory. “I think most polar scientists have considered water moving across the surface of Antarctica to be extremely rare. But we found a lot of it, over very large areas.”
Many of the newly mapped drainages start near mountains poking through glaciers, or in areas where powerful winds have scoured snow off underlying bluish ice. These features are darker than the mostly snow-covered ice sheet, and so absorb more solar energy. This causes melting, and on a slope, liquid water then melts a path downhill through overlying snow. If the continent warms this century as projected, this process will occur on a much larger scale, say the authors. “This study tells us there’s already a lot more melting going on than we thought,” said coauthor Robin Bell, a Lamont-Doherty polar scientist. “When you turn up the temperature, it’s only going to increase.”
DATE: April 18, 2017
SNIP: Climate change is causing thick ice deposits that form along Arctic rivers to melt nearly a month earlier than they did 15 years ago, a new study finds.
In the past, river icings have melted out around mid-July, on average. But a new study measuring the extent of river icings in the U.S. and Canadian Arctic shows most river icings disappeared 26 days earlier, on average, in 2015 than they did in 2000, melting around mid-June.
SOURCE: National Post
DATE: April 11, 2017
SNIP: Across Canada, the last of the snow and ice is melting away from a vast expanse of farmers’ fields, making way for the planting of this year’s crops.
And — suggests a new Canadian study — making an unexpectedly large contribution to greenhouse gases and climate change.
Strange as it might seem, the thawing of frozen cropland burps nitrous oxide into the atmosphere at rates far greater than previously thought, meaning agriculture’s role in producing the greenhouse gas has been greatly underestimated, according to research from the Universities of Guelph and Manitoba.
Nitrous oxide — commonly known as laughing gas and used as a dental anesthetic — accounts for well under 10 per cent of greenhouse gas emissions. But it’s almost 300 times as potent as carbon dioxide at trapping energy, the greenhouse effect believed to be warming the planet.
SOURCE: Washington Post
DATE: April 11, 2017
SNIP: The largest glacier in Greenland is even more vulnerable to sustained ice losses than previously thought, scientists have reported.
Jakobshavn glacier, responsible for feeding flotillas of icebergs into the Ilulissat icefjord — and possibly for unleashing the iceberg that sank the Titanic — is an enormous outlet for the larger Greenland ice sheet, which itself contains enough ice to raise seas by more than 20 feet.
But until now, researchers have not been sure how far Jakobshavn’s ice extends below sea level — or how much deeper it gets further inland. That’s crucial because Jakobshavn is undergoing a dangerous “marine ice sheet instability,” in which oceanfront glaciers that grow deeper further inland are prone to unstoppable retreat down what scientists call a “retrograde” slope.
That’s where the new science comes in: Researchers who flew over Jakobshavn in a helicopter toting a gravimeter, used to detect the gravitational pull of the ice and deduce its mass, say they’ve found the glacier extends even deeper below sea level than previously realized, a configuration that sets the stage for further retreat.
“The way the bed looks, sort of makes it more prone to continuous retreat for decades to come,” said one of the study’s authors, Eric Rignot, a researcher with NASA’s Jet Propulsion Laboratory and the University of California-Irvine.
SOURCE: National Observer
DATE: April 10, 2017
- The amount of carbon dioxide (CO2) in the atmosphere continues to accelerate upwards despite global efforts.
- The last two years had “unprecedented” increases.
- Canadian CO2 extraction is playing an oversized role.
The primary driver of global warming, disruptive climate changes and ocean acidification is the ever-increasing amount of carbon dioxide in our atmosphere.
Despite decades of global efforts towards climate policies, clean energy and efficiency, CO2 levels continue to rise and are actually accelerating upwards. For those of us hoping for signs of climate progress, this most critical and basic climate data is bitter news indeed. It shows humanity racing ever more rapidly into a full-blown crisis for both our climate and our oceans.
SOURCE: National Science Foundation
DATE: April 10, 2017
SNIP: Microbes in streams flowing on the surface of glaciers in the Arctic and Antarctic may represent a previously underestimated source of organic material and be part of an as yet undiscovered “dynamic local carbon cycle,” according to a new paper published by researchers supported by the National Science Foundation (NSF).
The cycle, they argue, could become a significant global source of carbon as temperatures rise worldwide and microbial activity increases.
Previously, scientists thought carbon released into polar streams by glaciers came from ancient organic material locked in the ice, or from newer sources, such as dust and soot blown in from fires and other sources around the world and deposited on the ice surface. Ice melt then releases that carbon into streams, which flow into the sea.
In the new study, researchers on a glacier in the Antarctic examined the ecosystem of a “supraglacial” stream — one that flows over its surface. Though these streams are among the largest ecosystems on most of the world’s glaciers, models of glacial contribution to the global carbon cycle have not previously considered their potential impact.
The researchers found that most of the carbon in the stream was produced by bacteria photosynthesizing — producing food from sunlight — rather than ancient carbon.
Although this is an initial study of the phenomenon, the research could indicate that as global temperatures rise, particularly in polar ecosystems, which are more sensitive to high temperatures, the microbial output of carbon could increase.