Greenland ice melting rapidly

Greenland ice melting rapidly

SOURCE: Ohio State News and National Geographic DATE: January 21, 2019 SNIP: Greenland is melting faster than scientists previously thought—and will likely lead to faster sea level rise—thanks to the continued, accelerating warming of the Earth’s atmosphere, a new study has found. Scientists concerned about sea level rise have long focused on Greenland’s southeast and northwest regions, where large glaciers stream iceberg-sized chunks of ice into the Atlantic Ocean. Those chunks float away, eventually melting. But a new study published Jan. 21 in the Proceedings of the National Academy of Sciences found that the largest sustained ice loss from early 2003 to mid-2013 came from Greenland’s southwest region, which is mostly devoid of large glaciers. “Whatever this was, it couldn’t be explained by glaciers, because there aren’t many there,” said Michael Bevis, lead author of the paper, Ohio Eminent Scholar and a professor of geodynamics at The Ohio State University. “It had to be the surface mass—the ice was melting inland from the coastline.” That melting, which Bevis and his co-authors believe is largely caused by global warming, means that in the southwestern part of Greenland, growing rivers of water are streaming into the ocean during summer. The key finding from their study: Southwest Greenland, which previously had not been considered a serious threat, will likely become a major future contributor to sea level rise. “We knew we had one big problem with increasing rates of ice discharge by some large outlet glaciers,” he said. “But now we recognize a second serious problem: Increasingly, large amounts of ice mass are going to leave as meltwater, as rivers that flow...
Melting Arctic ice is now pouring 14,000 tons of water per second into the ocean, scientists find

Melting Arctic ice is now pouring 14,000 tons of water per second into the ocean, scientists find

SOURCE: The Washington Post DATE: December 21, 2018 SNIP: A new scientific survey has found that the glaciers of the Arctic are the world’s biggest contributors to rising seas, shedding ice at an accelerating rate that now adds well over a millimeter to the level of the ocean every year. That is considerably more ice melt than Antarctica is contributing, even though the Antarctic contains far more ice. Still, driven by glacier clusters in Alaska, Canada and Russia and the vast ice sheet of Greenland, the fast-warming Arctic is outstripping the entire ice continent to the south — for now. However, the biggest problem is that both ice regions appear to be accelerating their losses simultaneously — suggesting that we could be in for an even faster rate of sea-level rise in future decades. For Arctic ice loss, “the rate has tripled since 1986,” said Jason Box, first author of the new study and a scientist at the Geological Survey of Denmark and Greenland. “So it clearly shows an acceleration of the sea-level contribution.” The total Arctic loss at present is 447 billion tons of ice per year — which Box calculated is about 14,000 tons of water per second. That’s for the period between 2005 and 2015. Between 1986 and 2005, the loss is calculated at around 5,000 tons per second — therefore, the rate has almost...
The Arctic is in even worse shape than you realize

The Arctic is in even worse shape than you realize

SOURCE: Washington Post DATE: December 11, 2018 SNIP: Over the last three decades of global warming, the oldest and thickest ice in the Arctic has declined by a stunning 95 percent, according the National Oceanic and Atmospheric Administration’s annual Arctic Report Card. The finding suggests that the sea at the top of the world has already morphed into a new and very different state, with major implications not only for creatures such as walruses and polar bears, but in the long term, perhaps, for the pace of global warming itself. The oldest ice can be thought of as a kind of glue that holds the Arctic together and, through its relative permanence, helps keep the Arctic cold even in long summers. If the Arctic begins to experience entirely ice-free summers, scientists say, the planet will warm even more, as the dark ocean water absorbs large amounts of solar heating that used to be deflected by the cover of ice. The new findings about the decreasing age of ice in the Arctic point to a less noticed aspect of the dramatic changes occurring there. When it comes to the icy cap atop the Arctic ocean, we tend to talk most often about its surface area — how much total ocean is covered by ice, rather than by open water. That’s easily visible — it can be glimpsed directly by satellite — and the area is, indeed, in clear decline. But the loss of old and thick ice, and the simultaneous decline in the total ice volume, is even larger — and arguably a much bigger deal. Young and thin ice...
Greenland is melting much faster than we thought

Greenland is melting much faster than we thought

SOURCE: Popular Science DATE: December 6, 2018 SNIP: Greenland is losing its cool. That’s not much of a surprise—its mile-thick sheet of ice was not made for this epoch of climate change. But that cool is getting shredded faster than we think. According to new findings published Wednesday in Nature, climate change has accelerated the melting of Greenland’s ice sheet to unparalleled levels, unseen in at least 350 years and likely in the past 7,800. The rate of melt and the resulting runoff falling into the ocean (and adding to a rising sea level) is speeding up over time, thanks to a motley of factors acting as a feedback loop. “By using ice cores, we can literally ‘drill back in time,’ and we are able to extend the observational period back in time ten-fold,” says Sarah Das, a glaciologist at Woods Hole Oceanographic Institution and a coauthor of the new study. In all, the team’s analysis suggests melt intensity in Greenland increased by a whopping 250 to 575 percent over just the last 20 years, relative to pre-industrial levels. In those same two decades, total ice sheet runoff has increased by 50 percent since the industrial age began, spiking up by 33 percent since the 20th century alone. Multiple factors are coalescing to create multiple feedback loops, all exacerbating the ice and snow melt. One of these is the melt-albedo feedback, in which melting creates a more granular consistency of snow that absorbs more sunlight and melts faster. Melting also exposes darker ice to sunlight, which warms up and melts faster than lighter shades of ice. And when melting...
Mysterious Microbes Turning Polar Ice Pink, Speeding Up Melt

Mysterious Microbes Turning Polar Ice Pink, Speeding Up Melt

SOURCE: National Geographic DATE: September 14, 2018 SNIP: A surprisingly happy and healthy ecosystem of algae is not only turning parts of the Greenland ice sheet pinkish-red, it’s contributing more than a little to the melting of one of the biggest frozen bodies of water in the world. The discolored snow isn’t just an Arctic phenomenon. “It’s actually a global occurrence,” says Alexandre Anesio, a biogeochemist from the University of Bristol. “In order for them to form visible blooms and increase the melting of the snow and ice, they just need the right conditions, which at a minimum involve basic nutrients and melting,” says Anesio. “As the climate gets warmer, the availability of liquid water from snow and ice becomes higher, favoring the growth of snow and ice algae.” “I think that this is increasingly becoming a problem in Arctic, Alpine, and Himalayan glaciers,” Anesio says. Blooms of red snow and brown ice are turning up in Antarctica, too. And experts are not accounting for the effect in their projections of global sea level rise, despite increasing evidence of what darkening snow is doing to the world’s glaciers. The darker surface [from the algae growth] lowers the “albedo,” or the ability of the ice to reflect the sunlight back into space, and that results in more light absorbed and more melting. As algae spreads over larger areas of the ice sheet, the effect will be compounded, leading to even more melting. A recent study found that algal blooms can contribute as much as 13 percent more ice melt over a season. So far, the blooms have not been taken...