by faster | Jul 11, 2019 | Blog
SOURCE: HuffPost DATE: July 11, 2019 SNIP: A historic slow-moving flood of polluted Mississippi River water loaded with chemicals, pesticides and human waste from 31 states and two Canadian provinces is draining straight into the marshes and bayous of the Gulf of Mexico — the nurseries of Arnesen’s fishing grounds — upsetting the delicate balance of salinity and destroying the fragile ecosystem in the process. As the Gulf waters warm this summer, algae feed on the freshwater brew, smothering oxygen-starved marine life. And as of Wednesday, an advancing storm looks likely to turn into a tropical storm or hurricane by the weekend, with the potential to bring torrential downpours and more freshwater flooding. Fishermen and state government officials agree this long, hot summer may go down in history as one of the most destructive years for Gulf fisheries. The torrent of river water pushing into Gulf estuaries is decimating crab, oyster and shrimp populations. The brown shrimp catch this spring in Louisiana and Mississippi is already down by an estimated 80%, and oysters are completely wiped out in some of the most productive fishing grounds in the country, according to state and industry officials. The polluted freshwater has also triggered algae blooms, which have led to beach closures across Mississippi. “We are seeing impacts across the coast in all sectors of the fishing communities,” said Patrick Banks, assistant secretary for the Louisiana Department of Wildlife and Fisheries. “We will continue to collect data to support a disaster declaration.” It’s not just fisheries that are suffering. Dolphins have been dying in huge numbers across the region — nearly 300 this...
by faster | Jul 11, 2019 | Blog
SOURCE: Inside Climate News DATE: July 11, 2019 SNIP: Under the choking black smoke from the bog and forest fires in Siberia and Alaska, it can feel like the Earth itself is burning. The normally moist, black organic peat soil and lush forests have been drying, and when they catch fire, they burn relentlessly. Global warming has been thawing tundra and drying vast stretches of the far-northern boreal forests, and it also has spurred more thunderstorms with lightning, which triggered many of the fires burning in Alaska this year, said Brian Brettschneider, a climate scientist with the International Arctic Research Center who closely tracks Alaskan and Arctic extreme weather. So far this year, wildfires have scorched more than 1.2 million acres in Alaska, making it one of the state’s three biggest fire years on record to this date, with high fire danger expected to persist in the weeks ahead. The large Arctic fires in June could be a sign of a climate tipping point, said Thomas Smith, a climate researcher at the London School of Economics and Political Science. “It really is unprecedented, a word we should not use lightly,” he wrote. “It may be that in most previous years, temperatures have never been warm enough to drive off moisture from the winter frost and snowpack. The ground is likely covered in mosses that act as a sponge, staying moist all summer long before freezing again in winter. But now that sponge is drying out.” Amid all of this, scientists in Alaska are worried about the future of scientific research at the region’s universities—the state legislature is struggling to...
by faster | Jul 10, 2019 | Blog
SOURCE: Reuters and PLOS One DATE: July 10, 2019 SNIP: A fifth of the world’s major cities will face “unknown” climate conditions by 2050, researchers warned on Wednesday, as rising temperatures heighten the risks of drought and flooding. Climate scientists at the Crowther Lab, a research group based at ETH Zurich, a science and technology university, analyzes 520 cities across the world, including all capitals and most urban centers with a population of more than 1 million. Looking at current climate conditions in these cities – including precipitation and seasonal data – scientists projected what would happen as temperatures rise another half degree, to near the lower 1.5 degree Celsius target set in the 2015 Paris Agreement on climate change. It showed that 22% of the cities will experience unprecedented climate conditions by 2050, such as more intense dry and monsoon seasons, said Jean Francis-Bastin, the lead author of the report. Crowther Lab scientists said their study, published in the journal PLOS ONE, was the first global analysis of the likely shifts in climate conditions in major cities as a result of global warming. It showed that 77% of the cities it looked at will experience a striking change in climate conditions by 2050. Across the northern hemisphere, many cities in 30 years time could resemble places that are over 1,000 km (620 miles) further south toward the equator, said the study, which projected conditions if current plans to cut climate-changing emissions go ahead. Of the 22% of cities that will see ‘unprecedented’ climate shifts, 64% are located in the tropics and include Kuala Lumpur, Jakarta, Rangoon and Singapore,...
by faster | Jul 10, 2019 | Blog
SOURCE: Think Progress and Nature Communications DATE: July 10, 2019 SNIP: Global warming limits laid out by the landmark Paris climate agreement do not rule out an Arctic devoid of summer sea ice, according to new research out this week. The findings, published July 9, are a grim indicator that even a best-case scenario for limiting climate impacts could still have unprecedented implications for the planet. They also underscore the potential for even more dire situations, which are growing more likely as countries, including the United States, fail to reach their individual climate goals under the Paris Agreement. Published by scientists from South Korea, Australia, and the United States, the new research appears in this week’s issue of Nature Communications and offers an ominous forecast for climate advocates. Using 31 different climate models, the experts found that there is at least a 6% probability that summer sea ice in the Arctic Ocean will disappear in a scenario long cited as the most optimistic: limiting global warming to 1.5 degrees Celsius. [T]his week’s study highlights the need to establish what level of warming would bring forth an ice-free Arctic — a scenario in which there would be no white mass of ice to reflect sunlight and maintain cooler ocean temperatures. The less sea ice there is to reflect the heat, the more warming is likely to occur. While the researchers note that Arctic sea ice is all but guaranteed to disappear in a situation involving more than 2 degrees Celsius of warming, the potential for such a melting at lower temperatures also remains cause for...
by faster | Jul 10, 2019 | Blog
SOURCE: Eurasia Review DATE: July 10, 2019 SNIP: Rising temperatures in the tundra of the Earth’s northern latitudes could affect microbial communities in ways likely to increase their production of greenhouse gases methane and carbon dioxide, a new study of experimentally warmed Alaskan soil suggests. About half of the world’s total underground carbon is stored in the soils of these frigid, northern latitudes. That is more than twice the amount of carbon currently found in the atmosphere as carbon dioxide, but until now most of it has been locked up in the very cold soil. The new study, which relied on metagenomics to analyze changes in the microbial communities being experimentally warmed, could heighten concerns about how the release of this carbon may exacerbate climate change. “We saw that microbial communities respond quite rapidly – within four or five years – to even modest levels of warming,” said Kostas T. Konstantinidis, the paper’s corresponding author and a professor in the School of Civil and Environmental Engineering and the School of Biological Sciences at the Georgia Institute of Technology. The study provides quantitative information about how rapidly microbial communities responded to the warming at critical depths, and highlights the dominant microbial metabolisms and groups of organisms that are responding to warming in the tundra. The work underscores the importance of accurately representing the role of soil microbes in climate models. “Because of the very large amount of carbon in these systems, as well as the rapid and clear response to warming found in this experiment and other studies, it is becoming increasingly clear that soil microbes – particularly those in...
by faster | Jul 9, 2019 | Blog
SOURCE: The Guardian DATE: July 9, 2019 SNIP: Antarctica faces a tipping point where glacial melting will accelerate and become irreversible even if global heating eases, research suggests. A Nasa-funded study found instability in the Thwaites glacier meant there would probably come a point when it was impossible to stop it flowing into the sea and triggering a 50cm sea level rise. Other Antarctic glaciers were likely to be similarly unstable. Recent research found the rate of ice loss from five Antarctic glaciers had doubled in six years and was five times faster than in the 1990s. Ice loss is spreading from the coast into the continent’s interior, with a reduction of more than 100 metres in thickness at some sites. The Thwaites glacier, part of the West Antarctic ice sheet, is believed to pose the greatest risk for rapid future sea level rise. Research recently published in the Proceedings of the National Academy of Sciences journal found it was likely to succumb to instability linked to the retreat of its grounding line on the seabed that would lead to it shedding ice faster than previously expected. Alex Robel, an assistant professor at the US Georgia Institute of Technology and the study’s leader, said if instability was triggered, the ice sheet could be lost in the space of 150 years, even if temperatures stopped rising. “It will keep going by itself and that’s the worry,” he said. Modelling simulations suggested extensive ice loss would start in 600 years but the researchers said it could occur sooner depending on the pace of global heating and nature of the...
