New CSU study eyes regional climate cycle as one factor
This year’s rapid loss of sea ice around Antarctica may make the floating ice shelves along the coast of the continent even more vulnerable to collapse, and a Hemisphere climate cycle known as the Southern Annular Mode is probably a factor in the equation.
Antarctic ice shelves are melting fastern than ever and sea ice globally is the lowest on record since accurate measurements started.
Scientists working in Greenland have been stunned by the speed at which ice is retreating.
Sea ice is vanishing around the Antarctic Peninsula, and there are signs the West Antarctic ice sheet may be prone to disintegration.
Coastal sea ice around Greenland.
An iceberg Arch in the Weddell Sea.
It’s hard to really get your head around what it means that the Arctic ice cap is literally melting away, and perhaps even harder to imagine that massive tracts of Antarctic ice are also giving way to global warming. But the science is pretty clear: During other epochs of Earth’s geological history, at times when there were similar global temperatures and about the same amount of CO2 in the atmosphere, so much ice melted that sea level was at least 20 feet higher than today. Today’s Earth — our Earth — seems to be responding the same way. For all of December, the extent of global sea ice has set record lows every single day. The Arctic meltdown is well documented by more than 100 years of data. Around the South Pole, more and more studies are showing warm layers of water melting large coastal slabs of ice that hold back the almost unimaginable masses of ice on the Antarctic continent. The images in this set are just snapshots, but what’s happening out there is very real. Take #climateaction now.
In another Christmas-themed story, I reported on a Norwegian study that showed how widespread grazing by reindeer affects the reflectivity in northern tundra regions. It turns out that when the ungulates munch shrubs and brush, they make the world cooler: Save the Reindeer, Save the Arctic.
Another sign that we may be near a climate tipping point is research from California showing that some severely burned forests just aren’t regenerating at all. The fires have become so big and so intense that all the seed stock trees are destroyed, leaving big cleared areas where there is no source for new growth — except for shrubs and brush that quickly grow to dominate the landscape and prevent new seedlings from taking root: California Forests Failing to Regrow After Intense Wildfires.
And some people think that they don’t have to worry about climate change because they heard global warming slowed down between 1998 and 2012. Not so, according to scientists who recalculated the rate of warming in the world’s oceans to show there was no hiatus: Already Debunked Global Warming ‘Hiatus’ Gets Another Dunking.
Antarctic sea ice retreat could set stage for ice shelf collapses
Staff ReportMonths of above-average temperatures in the Arctic slowed the growth of sea ice formation to a crawl during the second half of October, the National Snow and Ice Data Center reported in its latest monthly update.The ice scientists said that, starting Oct. 20, Arctic sea ice started setting daily record lows for extent. After mid-October, ice growth returned to near-average rates, but extent remained at record low levels through late October. Both sea surface and air temperatures have remained unusually high, extending from the surface high up into the atmosphere. Continue reading “Climate: Sea ice at both poles way below average”→
Australian scientists document early start to melt season
Australian scientists say Antarctic sea ice started its annual spring retreat early this year and has set new daily record lows for extent during late September — during the Austral spring, when Antarctic sea ice is at a maximum.
In a press release, the Antarctic Climate & Ecosystems Cooperative Research Centre said the sea ice extent started its annual retreat early, just two years after winter sea ice extent around Antarctica reached a new record high in September 2014, when it exceeded 20 million square kilometres for the first time since satellite measurements began in 1979.
This year, Antarctic sea ice began its annual spring retreat about four weeks earlier than average, after peaking at 18.5 million square kilometres on 28 August 2016, which was close to the lowest winter maximum on record.
Changes in ocean temperatures and sea ice formation around Antarctica could imperil the region’s krill — tiny crustaceans that are at the base of the food chain. Scientists say they’ve already documented a big drop in krill populations since the 1970s. Losing more krill would reduce the amount of food available for whales, penguins, seals, squid, fish and other marine life.
A new study published online in Geophysical Research Letters says up to 80 percent of suitable krill habitat could disappear by 2100. The research examines the effects of a warmer ocean and a decline in sea ice on these small crustaceans, said Andrea Piñones, a marine scientist at Center for Advance Studies in Arid Zones (Centro de Estudios Avanzados en Zonas Aridas) in Coquimbo, Chile, and lead author of the study. Continue reading “Antarctic krill could take a big global warming hit”→
New study offers climate clues from most recent interglacial warm period
By Bob Berwyn
The last time the Earth was as warm as today was about 128,000 years ago — and Antarctic sea ice extent was 65 percent smaller than it is now, according to British scientists who tracked past climate change in the region by studying ice core samples from that era.
That means Antarctic sea ice is on course to shrink dramatically in the decades and centuries ahead, said British Antarctic Survey scientist Max Holloway, who with a team of researchers analyzed oxygen isotopes in ice and air bubbles trapped for 128,000 years in the East Antarctic Ice Sheet. Continue reading “Antarctic sea ice meltdown likely in a warming world”→