As Arctic ice melts, polluting ships stream into polar waters

As Arctic ice melts, polluting ships stream into polar waters

SOURCE: Reuters DATE: August 27, 2020 SNIP: As melting sea ice opens the Arctic to navigation, more ships are plying the loosely regulated polar waters, bringing increasing amounts of climate-warming pollution, a Reuters analysis of new shipping and fuel-consumption data shows. Traffic through the icy region’s busiest lane along the Siberian coast increased 58% between 2016 and 2019. Last year, ships made 2,694 voyages on the Northern Sea Route, according to data collected by researchers from the Centre for High North Logistics at Norway’s Nord University. The trade is driven by commodities producers – mainly in Russia, China and Canada – sending iron ore, oil, liquefied natural gas (LNG) and other fuels through Arctic waters. Even the COVID-19 pandemic, which has significantly slowed shipping worldwide as supply chains have been disrupted, has not prevented traffic increasing on the Arctic artery. Ships made 935 voyages in the first half of 2020, up to the end of June, compared with 855 in the same period last year, the data shows. The increase in shipping is a worry for the environment. As those heavy ships burn fuel, they release climate-warming carbon dioxide as well as black soot. That soot blankets nearby ice and snow, absorbing solar radiation rather than reflecting it back out of the atmosphere, which exacerbates warming in the region. “The driving concern is the reduction of Arctic sea ice and the potential for more shipping,” said Sian Prior, lead adviser with the Clean Arctic Alliance. “We are already seeing that happen.” LNG tankers make up the largest proportion of traffic on the Northern Sea Route. They alone burned 239,000...
Antarctic Ocean Reveals New Signs of Rapid Melt of Ancient Ice, Clues About Future Sea Level Rise

Antarctic Ocean Reveals New Signs of Rapid Melt of Ancient Ice, Clues About Future Sea Level Rise

SOURCE: Inside Climate News DATE: May 28, 2020 SNIP: Climate researchers racing to calculate how fast and how high the sea level will rise found new clues on the seafloor around Antarctica. A study released today suggests that some of the continent’s floating ice shelves can, during eras of rapid warming, melt back by six miles per year, far faster than any ice retreat observed by satellites. As global warming speeds up the Antarctic meltdown, the findings “set a new upper limit for what the worst-case might be,” said lead author Julian Dowdeswell, director of the Scott Polar Research Institute at the University of Cambridge. The estimate of ice shelf retreat is based on a pattern of ridges discovered on the seafloor near the Larsen Ice Shelf. The spacing and size of the ridges suggest they were created as the floating ice shelves rose and fell with the tides while rapidly shrinking back from the ocean. In findings published today in Science, the researchers estimate that to corrugate the seafloor in this way, the ice would have retreated by more than 150 feet per day for at least 90 days. Ice shelves float on the ocean but they are fastened to land and act as stoppers that prevent Antarctic ice sheets that are as big as the U.S. and Mexico combined from sliding into the sea. The shelves are frozen to outcrops on the seafloor, but when they melt away from those anchor points, the flow of ice into the ocean speeds up, accelerating sea level rise. If the rate of retreat estimated by the new study extended across...
Climate crisis: Greenland’s ice faces melting ‘death sentence’

Climate crisis: Greenland’s ice faces melting ‘death sentence’

SOURCE: BBC DATE: September 3, 2019 SNIP: Greenland’s massive ice sheet may have melted by a record amount this year, scientists have warned. During this year alone, it lost enough ice to raise the average global sea level by more than a millimetre. Researchers say they’re “astounded” by the acceleration in melting and fear for the future of cities on coasts around the world. One glacier in southern Greenland has thinned by as much as 100 metres since I last filmed on it back in 2004. Another revelation is that the ice is not only being melted by the air, as the atmosphere heats up, but also by warmer water reaching underneath the fronts of the glaciers. One Nasa scientist describes the ice as being under a hair-dryer and at the same time also on a cooker. One of the scientists studying the ice sheet, Dr Jason Box of the Geological Survey of Denmark and Greenland (GEUS), says he’s unnerved by the potential dangers and that coastal planners need to “brace themselves”. “Now that I’m starting to understand more of the consequences, it’s actually keeping me awake at night because I realise the significance of this place around the world and the livelihoods that are already affected by sea level rise,” he told me. According to Dr Box, it’s the recent increase in the average temperature that’s being felt in Greenland’s ice: “Already effectively that’s a death sentence for the Greenland ice sheet because also going forward in time we’re expecting temperatures only to climb,” he said. “So, we’re losing Greenland – it’s really a question of how...
Study Predicts More Long-Term Sea Level Rise from Greenland Ice

Study Predicts More Long-Term Sea Level Rise from Greenland Ice

SOURCE: NASA DATE: June 19, 2019 SNIP: In the next 200 years, the ice sheet model shows that melting at the present rate could contribute 19 to 63 inches to global sea level rise, said the team led by scientists at the Geophysical Institute at the University of Alaska Fairbanks. These numbers are at least 80 percent higher than previous estimates, which forecasted up to 35 inches of sea level rise from Greenland’s ice. The team ran the model 500 times out to the year 3000 for each of three possible future climate scenarios, adjusting key land, ice, ocean and atmospheric variables to test their effects on ice melt rate. The three climate scenarios depend on the amount of greenhouse gas emissions in the atmosphere in coming years. In the scenario with no reduction of emissions, the study found that the entire Greenland Ice Sheet will likely melt in a millennium, causing 17 to 23 feet of sea level rise. Capturing the changing flow and speed of outlet glacier melt makes the updated ice sheet model more accurate than previous models, according to the authors. As ocean waters have warmed over the past 20 years, they have melted the floating ice that shielded the outlet glaciers from their rising temperatures. As a result, the outlet glaciers flow faster, melt and get thinner, with the lowering surface of the ice sheet exposing new ice to warm air and melting as well. Each of the three emissions scenarios used in the study produced different patterns of ice retreat across Greenland. The least severe scenario showed the ice retreating in the west...
Melting ice sheets release tons of methane into the atmosphere

Melting ice sheets release tons of methane into the atmosphere

SOURCE: Phys.org DATE: January 3, 2019 SNIP: The Greenland Ice Sheet emits tons of methane according to a new study, showing that subglacial biological activity impacts the atmosphere far more than previously thought. An international team of researchers led by the University of Bristol camped for three months next to the Greenland Ice Sheet, sampling the meltwater that runs off a large catchment (> 600 km2) of the Ice Sheet during the summer months. As reported in Nature, using novel sensors to measure methane in meltwater runoff in real time, they observed that methane was continuously exported from beneath the ice. They calculated that at least six tons of methane was transported to their measuring site from this portion of the Ice Sheet alone. Professor Jemma Wadham, Director of Bristol’s Cabot Institute for the Environment, who led the investigation, said: “A key finding is that much of the methane produced beneath the ice likely escapes the Greenland Ice Sheet in large, fast flowing rivers before it can be oxidized to CO2, a typical fate for methane gas which normally reduces its greenhouse warming...