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Rain Is Melting Greenland’s Ice, Even in Winter
The Greenland ice sheet loses about 270 billion tons of ice each year to climate change, raising global sea levels by 7.5 millimeters (approximately 0.3 inches) between 1992 and 2011, Science Magazine explained. About half of that was due to the calving of icebergs, but recent satellite observations have revealed that 70 percent of Greenland's contribution to global sea level rise in recent years has come from meltwater running off into the ocean. Scientists wanted to understand what was driving the meltwater.
The results of one investigation, published in The Cryosphere Wednesday, show that a third of the runoff observed by the research team between 1979 and 2012 was caused by rainfall, Columbia University's Earth Institute reported. Over that same period, rain-caused melt doubled during summer and tripled during winter. Total precipitation over Greenland did not change, but the balance of snow to rain shifted.
"We were surprised that there was rain in the winter," lead study author Dr. Marilena Oltmanns of the GEOMAR Helmholtz Centre for Ocean Research Kiel in Germany told BBC News. "It does make sense because we're seeing flows of warm air coming up from the South, but it's still surprising to see that associated with rainfall."
In order to reach their conclusions, the researchers used satellite data to determine when melting was taking place as well as automated readings from 20 weather stations to determine when rainfall occurred. They pinpointed 313 incidents over the study period when rainfall triggered melting, according to Science.
Rain can lead to more melting even if it falls in winter and refreezes right away, study author Marco Tedesco explained to BBC News. That's because it leaves the ice both darker and smoother. Darker ice absorbs more heat from the sun, leading to more melt, and smooth ice enables that melt to flow faster over its surface.
"The potential impact of changes taking place in the winter and spring on what happens in summer needs to be understood," Tedesco said.
Professor Jason Box, a Geological Survey of Denmark and Greenland glaciologist not involved with this study, told BBC News he had observed first-hand during a research trip how rain could transform the ice sheet:
"After weeks of sunshine, it started raining on us and it completely transformed the surface—it got darker.
"And I became convinced—only by being there and seeing it with my own eyes—that rain is just as important as strong sunny days in melting the Greenland ice sheet."
The winter rain usually falls in lower elevations in Greenland's south and southwest, where it is carried on warm, wet winds from the south that may be getting more common as climate change shifts the jet stream, The Earth Institute explained.
"This is what climate change looks like, it's the 'Atlantification' of the Arctic," climate scientist Ruth Mottram of the Danish Meteorological Institute in Copenhagen, who did not participate in the study, told Science Magazine. "This paper identifies a really important mechanism and we need to figure out how it plays into our predictions of sea level rise."
If all the ice in Greenland melted, it would raise global sea levels by 7 meters (approximately 23 feet). Most projections say that sea levels will rise two to four feet by 2100, The Earth Institute said, but more research is needed to determine how much Greenland and Antarctica will contribute.
- Global CO2 emissions hit record high in 2018, as Greenland ice ... ›
- Greenland's ice sheet holds clues to global sea-level rise and ... ›
- Massive Impact Crater Beneath Greenland Could Explain Ice Age ... ›
- Sea Ice Falls to Record Lows in Arctic and Antarctic - EcoWatch ›
- It really shouldn't be raining on the Greenland ice sheet in winter ... ›
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Global Banks, Led by JPMorgan Chase, Invested $1.9 Trillion in Fossil Fuels Since Paris Climate Pact
By Sharon Kelly
A report published Wednesday names the banks that have played the biggest recent role in funding fossil fuel projects, finding that since 2016, immediately following the Paris agreement's adoption, 33 global banks have poured $1.9 trillion into financing climate-changing projects worldwide.
By Patti Lynn
2018 was a groundbreaking year in the public conversation about climate change. Last February, The New York Times reported that a record percentage of Americans now believe that climate change is caused by humans, and there was a 20 percentage point rise in "the number of Americans who say they worry 'a great deal' about climate change."
England faces an "existential threat" if it does not change how it manages its water, the head of the country's Environment Agency warned Tuesday.
By Jessica Corbett
A new analysis revealed Tuesday that over the past two decades heat records across the U.S. have been broken twice as often as cold ones—underscoring experts' warnings about the increasingly dangerous consequences of failing to dramatically curb planet-warming emissions.
By Madison Dapcevich
Ask any resident of San Francisco about the waterfront parrots, and they will surely tell you a story of red-faced conures squawking or dive-bombing between building peaks. Ask a team of researchers from the University of Georgia, however, and they will tell you of a mysterious string of neurological poisonings impacting the naturalized flock for decades.
The initial cause of the fire was not yet known, but it has been driven by the strong wind and jumped the North Santiam River, The Salem Statesman Journal reported. As of Tuesday night, it threatened around 35 homes and 30 buildings, and was 20 percent contained.
The unanimous verdict was announced Tuesday in San Francisco in the first federal case to be brought against Monsanto, now owned by Bayer, alleging that repeated use of the company's glyphosate-containing weedkiller caused the plaintiff's cancer. Seventy-year-old Edwin Hardeman of Santa Rosa, California said he used Roundup for almost 30 years on his properties before developing non-Hodgkin's lymphoma.
"Today's verdict reinforces what another jury found last year, and what scientists with the state of California and the World Health Organization have concluded: Glyphosate causes cancer in people," Environmental Working Group President Ken Cook said in a statement. "As similar lawsuits mount, the evidence will grow that Roundup is not safe, and that the company has tried to cover it up."
Judge Vince Chhabria has split Hardeman's trial into two phases. The first, decided Tuesday, focused exclusively on whether or not Roundup use caused the plaintiff's cancer. The second, to begin Wednesday, will assess if Bayer is liable for damages.
"We are disappointed with the jury's initial decision, but we continue to believe firmly that the science confirms glyphosate-based herbicides do not cause cancer," Bayer spokesman Dan Childs said in a statement reported by The Guardian. "We are confident the evidence in phase two will show that Monsanto's conduct has been appropriate and the company should not be liable for Mr. Hardeman's cancer."
Some legal experts said that Chhabria's decision to split the trial was beneficial to Bayer, Reuters reported. The company had complained that the jury in Johnson's case had been distracted by the lawyers' claims that Monsanto had sought to mislead scientists and the public about Roundup's safety.
However, a remark made by Chhabria during the trial and reported by The Guardian was blatantly critical of the company.
"Although the evidence that Roundup causes cancer is quite equivocal, there is strong evidence from which a jury could conclude that Monsanto does not particularly care whether its product is in fact giving people cancer, focusing instead on manipulating public opinion and undermining anyone who raises genuine and legitimate concerns about the issue," he said.
Many regulatory bodies, including the U.S. Environmental Protection Agency, have ruled that glyphosate is safe for humans, but the World Health Organization's International Agency for Research on Cancer found it was "probably carcinogenic to humans" in 2015. A university study earlier this year found that glyphosate use increased cancer risk by as much as 41 percent.
Hardeman's lawyers Jennifer Moore and Aimee Wagstaff said they would now reveal Monsanto's efforts to mislead the public about the safety of its product.
"Now we can focus on the evidence that Monsanto has not taken a responsible, objective approach to the safety of Roundup," they wrote in a statement reported by The Guardian.
Hardeman's case is considered a "bellwether" trial for the more than 760 glyphosate cases Chhabria is hearing. In total, there are around 11,200 such lawsuits pending in the U.S., according to Reuters.
University of Richmond law professor Carl Tobias told Reuters that Tuesday's decision showed that the verdict in Johnson's case was not "an aberration," and could possibly predict how future juries in the thousands of pending cases would respond.