Polar Melting
A massive waterfall formed on Greenland's ice sheet. Here's why it matters
Scientists from the University of Cambridge in the UK recorded the extraordinary phenomenon through the use of aerial drones.
Their study, published this week in the journal Proceedings of the National Academy of Sciences, investigates the link between this transfer of meltwater to the bottom of the ice and rising global sea levels. Greenland has the world's second-largest ice sheet, and is the single largest contributor to global sea-level rise, the study said.
"Before this study, we already knew that many lakes drain and that fractures may be important in the lake drainage process, but the formation of fractures in terms of 'where', 'when' and 'how' has not been studied before, at least not with the resolution and details featured in our work," one of the researchers, Poul Christoffersen, from Cambridge's Scott Polar Research Institute, who led the research told CNN via e-mail.
What’s Driving Antarctica's Meltdown?
Now, new research is highlighting another threat: Since 2000, moist and warm tendrils of air known as atmospheric rivers have been swirling toward the coast more frequently, bringing more rain and surface melting. Antarctica has been losing about 250 billion tons of ice annually in recent years, and research shows the rate has increased sixfold since 1979. At this pace, researchers have suggested, West Antarctica's ice shelves may reach climate tipping points and crumble, sending sea level rise surging well beyond current projections.
Arctic Shifts to Carbon Source – Stunning Reversal After Capturing Carbon for Tens of Thousands of Years
A NASA-funded study suggests winter carbon emissions in the Arctic may be adding more carbon into the atmosphere each year than is taken up by Arctic vegetation, marking a stark reversal for a region that has captured and stored carbon for tens of thousands of years. The study, published October 21, 2019, in Nature Climate Change, warns that winter carbon dioxide loss from the world’s permafrost regions could increase by 41% over the next century if human-caused greenhouse gas emissions continue at their current pace. Carbon emitted from thawing permafrost has not been included in the majority of models used to predict future climates.
Large loss of CO2 in winter observed across the northern permafrost region
We estimate a contemporary loss of 1,662 TgC per year from the permafrost region during the winter season (October–April). This loss is greater than the average growing season carbon uptake for this region estimated from process models (−1,032 TgC per year). Extending model predictions to warmer conditions up to 2100 indicates that winter CO2 emissions will increase 17% under a moderate mitigation scenario—Representative Concentration Pathway 4.5—and 41% under business-as-usual emissions scenario—Representative Concentration Pathway 8.5. Our results provide a baseline for winter CO2 emissions from northern terrestrial regions and indicate that enhanced soil CO2 loss due to winter warming may offset growing season carbon uptake under future climatic conditions.
Alaska's Hottest Month on Record: Melting Sea Ice, Wildfires and Unexpected Die-Offs
Arctic sea ice hit a record low in July after an early start to the melt season, according to the National Snow and Ice Data Center (NSIDC). The sea ice volume Arctic-wide was about 47 percent lower than the average from 1979-2018. In Alaska, the ice is now about 150 miles from shore—a phenomenon that has only occurred in recent years and never before September, according to Rick Thoman, a climate scientist with the Alaska Center for Climate Assessment and Policy.
Research Highlight: Loss of Arctic's Reflective Sea Ice Will Advance Global Warming by 25 Years
Losing the remaining Arctic sea ice and its ability to reflect incoming solar energy back to space would be equivalent to adding one trillion tons of CO2 to the atmosphere, on top of the 2.4 trillion tons emitted since the Industrial Age, according to current and former researchers from Scripps Institution of Oceanography at the University of California San Diego.
At current rates, this roughly equates to 25 years of global CO2 emissions. It would consequently speed up the arrival of a global threshold of warming of 2ºC beyond temperatures the world experienced before the Industrial Revolution. Scientists and analysts, including the authors of an Intergovernmental Panel on Climate Change Special Report released in October 2018, have stated that the planet runs the risk of catastrophic damage ranging from more intense heat waves and coastal flooding to extinction of terrestrial species and threats to food supply if that threshold is passed.
What does ‘shrubification’ mean for the Arctic?
In a 2017 literature review of 60 studies looking at shrub changes — including both the expansion of the shrub line and growth of existing shrub populations — across the high-latitude tundra, Myers-Smith and her co-author state that all studies found evidence of shrub line advance and growing populations. These studies spanned the Arctic, with sites in Northern Alaska, Canada, Scandinavia and Russia. The authors predicted that if conditions that favor shrub growth continue, tall willow cover in the region could increase by 20 percent in the next 50 years
Marine ice sheet instability amplifies and skews uncertainty in projections of future sea-level rise
We have shown that model ensembles can be used to quantify a range of possible scenarios for future sea-level rise, including potentially catastrophic scenarios of rapid sea-level rise. However, large model ensembles can be prohibitively expensive when extended to the entire Antarctic Ice Sheet. To fully capture the complete range of possible Antarctic futures, we will need efficient methods for uncertainty quantification (32, 37) and model order reduction that captures the complexities of ice sheet dynamics (31, 34). Such sophisticated methods will ensure that we can make the most useful sea-level projections beyond 2100 for those stakeholders who depend on them.
Greenland Ice Melt Today
National Snow & Ice Data Center 6/16/2019
Get daily satellite images and information about melting on the Greenland ice sheet. We post analysis periodically as conditions warrant.
Climate crisis: Alaska is melting and it’s likely to accelerate global heating
The breakneck speed of Alaska’s rising heat is having cascading consequences, with vanishing sea ice exposing coastal communities to storms, altered wildlife and plant patterns that make it harder for people to find food. There is also a growing wildfire threat putting communities at risk.
Mass Die-Off of Puffins Raises More Fears About Arctic's Warming Climate
Inside Climate News 06/01/2019
The people of St. Paul Island, an Aleut community in the Bering Sea, are accustomed to seeing a lot of birds—millions stop there during their annual migrations. But they're not used to seeing them like this. What was happening in October 2016 was the beginning of a mass die-off. Thousands of tufted puffins were dying for no apparent reason, except for maybe one: changes in the ecosystem due to climate change.
‘Extraordinary thinning’ of ice sheets revealed deep inside Antarctica
The Guardian Thinning Ice Sheets 5/16/2019
The warming of the Southern Ocean is resulting in glaciers sliding into the sea increasingly rapidly, with ice now being lost five times faster than in the 1990s. The West Antarctic ice sheet was stable in 1992 but up to a quarter of its expanse is now thinning. More than 100 metres of ice thickness has been lost in the worst-hit places.
Daily Kos Greenland Heat Dome
Daily Kos Greenland Heat Dome 4/29/2019
Greenland’s Snow and Ice started melting in early April this year, weeks earlier than normal. Unprecedented early surface melting is well underway on the southeastern coastline now.
Arctic Sea Ice Minimum 2019
The extent of Arctic sea ice at the end of this summer was effectively tied with 2007 and 2016 for second lowest since satellite monitoring began. An analysis of satellite data by NASA and the National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder shows that the 2019 minimum extent, which was likely reached on Sept. 18, measured 1.60 million square miles (4.15 million square kilometers).
In this animation, the daily Arctic sea ice and seasonal land cover change progress through time, from the yearly maximum ice extent on March 13, 2019, through its minimum on September 18, 2019. Over the water, Arctic sea ice changes from day to day showing a running 3-day minimum sea ice concentration in the region where the concentration is greater than 15%. The blueish white color of the sea ice is derived from a 3-day running minimum of the AMSR2 89 GHz brightness temperature. Over the terrain, monthly data from the seasonal Blue Marble Next Generation fades slowly from month to month.
‘Archived’ heat has reached deep into the Arctic interior, researchers say
Yale News-Archived Heat in the Arctic
Arctic sea ice isn’t just threatened by the melting of ice around its edges, a new study has found: Warmer water that originated hundreds of miles away has penetrated deep into the interior of the Arctic. That “archived” heat, currently trapped below the surface, has the potential to melt the region’s entire sea-ice pack if it reaches the surface, researchers say.
Scientists are keeping a close eye on the Beaufort Gyre
The Beaufort Gyre, an immense 60-mile-diameter pool of cold freshwater and sea ice, is “stuck” in a clockwise rotation that should have ended years ago. Its eventual reversal could send massive amounts of chilly water straight toward western Europe, plunging it into brutal winters and disrupting fisheries.
Warming of the interior Arctic Ocean linked to sea ice losses at the basin margins
Science Advances- Warming of the interior Arctic Ocean linked to sea ice losses at the basin margins
Arctic Ocean measurements reveal a near doubling of ocean heat content relative to the freezing temperature in the Beaufort Gyre halocline over the past three decades (1987–2017). This warming is linked to anomalous solar heating of surface waters in the northern Chukchi Sea, a main entryway for halocline waters to join the interior Beaufort Gyre.
If We Lose the Ice we Lose the Entire Ecosystem
Paul Nicklen- If we lose the ice we lose the ecosystem 8/18
The photographer has been documenting life at the poles for years. He is determined to safeguard these fragile habitats
'We've never seen this': Massive Canadian Glaciers Shrinking Rapidly
The Guardian- Glacier Shrinkage-10/30/2018
Scientists in Canada have warned that massive glaciers in the Yukon territory are shrinking even faster than would be expected from a warming climate – and bringing dramatic changes to the region.
