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...
The Arctic is turning brown because of weird weather – and it could accelerate climate change

The Arctic is turning brown because of weird weather – and it could accelerate climate change

SOURCE: The Conversation DATE: November 26, 2018 SNIP: Over the last few years Arctic scientists have reported a surprising finding: large areas of the Arctic are turning brown. This is in part due to extreme events linked to winter weather, such as sudden, short-lived periods of extreme warmth. These events are occurring as the climate warms, which is happening twice as fast in the Arctic compared with the rest of the planet. Extreme events are therefore happening more and more often, with increasingly severe effects – including widespread damage and death in Arctic plants. This “browning” of plant communities has happened over thousands of square kilometres or more. However, until recently we knew very little about what this might mean for the balance between carbon uptake and release in Arctic ecosystems. Given that the Arctic stores twice as much carbon as the atmosphere, this is a pressing concern. Now, our study has shown that extreme climatic events can significantly reduce the ability of Arctic ecosystems to take up carbon –- with implications for whether the Arctic will help combat climate change, or accelerate it. Here we found the effects of two extreme winter weather events. First, “frost drought” had caused extensive plant dieback. Frost drought occurs when the insulating layer of snow which usually protects plants from the harsh Arctic winter is melted, typically by unusually high winter temperatures. If plants remain exposed to cold, windy conditions for long enough, they continually lose water and are unable to replace it from the frozen soil. Eventually, they succumb to drought. The second event was “extreme winter warming” – a sudden...
Arctic warming: More shipping, more risks to marine mammals

Arctic warming: More shipping, more risks to marine mammals

SOURCE: Yale Climate Connections DATE: Nov 11, 2018 SNIP: The high Arctic long has been seen as a vast, impassable span of ice accessed only by intrepid and daring explorers. But as more sea ice melts, the region is becoming more accessible, and travel by ship is now possible under certain conditions. As global temperatures warm and more water opens up, vessel traffic continues to rise, from shippers seeking shortened – and more profitable – transit routes to tourists looking for new bucket-list experiences. This year, a container ship brought cargo along the Northern Sea Route for the first time, and in 2016, and again in 2017, a luxury cruise ship with more than 1,000 passengers transited the Northwest Passage. With scientists predicting an ice-free Arctic summer possible as soon as 2040, this uptick in vessel traffic – and the projected further increase in traffic – has marine biologists worried. University of Washington marine biologist Kristin Laidre and colleagues recently published a study in PNAS exploring the threat increased vessel traffic poses to Arctic marine mammals. “There was room for a broad pan-Arctic look at how that might affect these ice-associated or ice-obligated marine mammals that live up there because they really haven’t experienced this kind of human activity in their evolutionary history, so it’s going to be a pretty big change for them,” Laidre says. The team studied seven species – beluga whales, narwhals, bowhead whales, ringed seals, bearded seals, walruses, and polar bears – and examined 80 subpopulations of these animals to assess their vulnerability during the month of September. The researchers found that 42 of the...
Climate Change: Arctic ‘no safe harbour’ for breeding birds

Climate Change: Arctic ‘no safe harbour’ for breeding birds

SOURCE: BBC News DATE: November 9, 2018 SNIP: The Arctic is no longer the safe haven it once was for nesting birds, a new scientific report warns. Having nests raided by predators is a bigger threat for birds flocking to breed than in the past, it shows. This raises the risk of extinction for birds on Arctic shores, say researchers. They point to a link with climate change, which may be changing the behaviour and habitat of animals, such as foxes, which steal eggs. “We’re seeing the sad implication of climate change,” Prof Székely told BBC News, “because our data show that the impact of climate change is involved, driving increased nest predation among these shorebirds – sandpipers, plovers and the likes.” Shore birds breed on the ground; their eggs and offspring are exposed, where they can fall prey to predators such as snakes, lizards and foxes. Rates of daily nest predation in the Arctic have increased three-fold in the last 70 years. A two-fold increase was found in Europe, most of Asia and North America, while a smaller change was observed in the tropics and Southern...