The warmer Arctic has triggered cooler winters and springs in North America, which has in turn weakened vegetation growth and lowered carbon uptake capacity in its ecosystems, research shows.
The team analyzed an index of sea surface temperatures from the Bering Sea and found that in years with higher than average Arctic temperatures, changes in atmospheric circulation resulted in the aforementioned anomalous climates throughout North America. In those years of intense cold and low precipitation, the team found that the unfavorable conditions adversely affected vegetation growth — including crop yields — which in turn decreased carbon uptake capacity by about 14%. In other words, although Arctic warming has increased carbon uptake in the Northern Hemisphere, this research has shown that the resulting interannual variability in Arctic temperatures can affect regions further away in North America and may counteract the initially observed increases in carbon uptake…
Jin-Soo Kim, Jong-Seong Kug, Su-Jong Jeong, Deborah N. Huntzinger, Anna M. Michalak, Christopher R. Schwalm, Yaxing Wei, Kevin Schaefer. Reduced North American terrestrial primary productivity linked to anomalous Arctic warming. Nature Geoscience, 2017; DOI: 10.1038/ngeo2986
..in the latest sign of how quickly changes are happening, new research published this week shows that the Arctic has seen more frequent bouts of warm air and longer stretches of mild weather. The new findings show that while warm snaps have occurred even as far as back as the 1890s, a massive shift is afoot in the region, which is warming twice as fast as the rest of the world…
Background temperatures have also been rising faster there. The North Pole region has warmed 2.3°F (1.3°C) per decade since 1979, a trend largely driven by climate change. Though the new study doesn’t tease out whether the increase in warm days is due directly to climate change, it’s part of a hugepileofevidence of how rising carbon pollution is altering the Arctic faster than the rest of the world….
….The winter of 2015-2016, for example, saw temperatures nearly 3.6 degrees Fahrenheit (2 degrees Celsius) warmer than the previous record high monthly winter temperature. At the end of December 2015, scientists recorded a temperature of 36 degrees Fahrenheit (2.2 degrees Celsius) in the Central Arctic, the warmest temperature ever recorded in this region from December through March.
…On average, the Atlantic side of the North Pole now has ten warming events each winter, while the Pacific Central Arctic has five such events, according to the study. More storms come in to the Arctic from the Atlantic Ocean during winter, which results in more warming events on the Atlantic side of the North Pole….
Robert M. Graham, Lana Cohen, Alek A. Petty, Linette N. Boisvert, Annette Rinke, Stephen R. Hudson, Marcel Nicolaus, Mats A. Granskog. Increasing frequency and duration of Arctic winter warming events. Geophysical Research Letters, 2017; DOI: 10.1002/2017GL073395
“It’s another sign that the Arctic is unraveling. We had heat waves in the central Arctic last winter, record-low winter sea ice coverage, and even periods of ice retreat when it should be growing,” said Mark Serreze, director of the National Snow and Ice Data Center.
The Arctic’s record-warm winter has allowed thousands of square miles of sea ice off Alaska to melt more than a month early, leaving the shoreline vulnerable to waves and exposing dark ocean water to absorb more heat from the sun…As of May 24, the ice cover on the Chukchi Sea had melted away from the shore along a 300 mile stretch, from Point Hope all the way to Barrow, the northernmost town in the United States. Satellite and radar data show the ice-free area totaled about 54,000 square miles.
The huge area of open water off the coast is something you would normally see in early July, said Mark Serreze, director of the National Snow and Ice Data Center. The rapid disintegration of the Chukchi Sea ice is an “exclamation point” on a remarkable series of rapid fire Arctic changes, he said.
“It’s another sign that the Arctic is unraveling. We had heat waves in the central Arctic last winter, record-low winter sea ice coverage, and even periods of ice retreat when it should be growing. These extremes are moving from place to place,” Serreze said. The Arcticclimate change underway is caused by the buildup of heat-trapping greenhouse gases.
…The rapid recent decline in ice coverage and thickness has led researchers to believe that most of the Arctic Ocean will be free of ice in the summers as soon as the mid-2020s.
NSIDC researcher Julienne Stroeve, currently based at University College, London, said at a recent science conference that each of the last 10 years saw record-low sea ice coverage, and that there were seven months of record-low sea ice conditions during 2016, setting the stage for a Chukchi Sea meltdown.
Sea ice conditions were so unusual in late 2016 that NSIDC lead scientist Ted Scambos called it a black swan event in December, after reporting record low ice extent in the Arctic and Antarctica, far below natural historic variations. In mid-November 2016, much of the Arctic—spanning an area as large as the lower 48 states—was 30 to 35 degrees above average.
…a large part of the world’s coast is Arctic, and that erosion, on average, is taking a 1.5-foot bite out of that coastline each year, said Michael Fritz, a polar and ocean researcher with the Alfred Wegener Institute in Potsdam, Germany.
Continued freak warmth in the Arctic helped propel global average temperatures to the second-warmest level on record for the month of April, NASA reported on Monday.
The new findings illustrate how the planet is still setting climate milestones even in the absence of other factors that tend to elevate global air and sea temperatures, such as an El Niño event.
This makes clear the growing influence of human-caused global warming on the planet’s climate, month after month, year after year, as the amounts of planet-warming greenhouse gases in the atmosphere continue to rise to levels unseen during all of human history. …The top 3 hottest months of April to occur since instrument records began in 1880 have all taken place since 2010.
…For April of 2017, the story is dominated by unusual warmth in parts of the Arctic, including across Siberia, parts of China, Alaska and the northwest portions of the Arctic Ocean. Greenland, however, had below average temperatures for the month, though that weather pattern reversed itself in early May.
Arctic sea ice tied for for the lowest level on record during the month of April, after setting record lows throughout the fall and winter. The sea ice cover, which has been declining since satellites first began keeping tabs on it in 1979, is now far thinner and younger than average as it enters the summer melt season. (Older, thicker ice has a higher chance of surviving the summer melt.) …
This April merely tied April 2016 for the lowest extent on record, but it’s hardly reason to celebrate. The Arctic was missing 394,000 square miles of ice, with each day setting a record low or within 36,000 square miles of setting one…
….One of the biggest issues for sea ice is its increasingly youthful appearance. Young ice is more susceptible to the vagaries of weather, whether it be warm air or water or storms that knock it around and break it up.
Ice older than five years in age now only comprises 5 percent of the Arctic’s ice pack. It accounted for 30 percent of all Arctic sea ice in 1984, but relentless warmth driven by rising carbon dioxide in the atmosphere has slowly squeezed it out of existence….
Arctic sea ice extent has trended in record low territory for months.Credit: Zack Labe
In the past, scientists typically avoided linking individual weather events to climate change, citing the challenges of teasing apart human influence from the natural variability of the weather. But that is changing.
…In a new study, published in this week’s issue of Proceedings of the National Academy of Sciences, Diffenbaugh and a group of current and former Stanford colleagues outline a four-step “framework” for testing whether global warming has contributed to record-setting weather events. The new paper is the latest in a burgeoning field of climate science called “extreme event attribution,” which combines statistical analyses of climate observations with increasingly powerful computer models to study the influence of climate change on individual extreme weather
….”Our results suggest that the world isn’t quite at the point where every record hot event has a detectable human fingerprint, but we are getting close,” Diffenbaugh said. For the driest and wettest events, the authors found that human influence on the atmosphere has increased the odds across approximately half of the area that has reliable observations.
….One high-profile test case was Arctic sea ice, which has declined by around 40 percent during the summer season over the past three decades. When the team members applied their framework to the record-low Arctic sea ice cover observed in September 2012, they found overwhelming statistical evidence that global warming contributed to the severity and probability of the 2012 sea ice measurements. “The trend in the Arctic has been really steep, and our results show that it would have been extremely unlikely to achieve the record-low sea ice extent without global warming,” Diffenbaugh said.
Noah S. Diffenbaugh, Deepti Singh, Justin S. Mankin, Daniel E. Horton, Daniel L. Swain, Danielle Touma, Allison Charland, Yunjie Liu, Matz Haugen, Michael Tsiang, Bala Rajaratnam. Quantifying the influence of global warming on unprecedented extreme climate events. Proceedings of the National Academy of Sciences, 2017; 201618082 DOI: 10.1073/pnas.1618082114
Evidence continues to mount that climate change has pushed the Arctic into a new state. Skyrocketing temperatures are altering the essence of the region, melting ice on land and sea, driving more intense wildfires, altering ocean circulation and dissolving permafrost.
A new report chronicles all these changes and warns that even if the world manages to keep global warming below the targeted 2°C threshold, some of the shifts could be permanent. Among the most harrowing are the disappearance of sea ice by the 2030s and more land ice melt than previously thought, pushing seas to more extreme heights.
This past winter is just the latest in a string of bizarre years and the report, authored by 90 Arctic experts, is the latest in a long line of increasingly dire warnings for the fastest-warming region on the planet. If carbon pollution isn’t slowed, parts of the Arctic could warm a whopping 16°F by the 2050s….
…The new analysis shows that the average number of days with sea ice cover has dropped by 10-20 days per decade since 1979….
The massive rush of freshwater into the Arctic Ocean is also reshaping ocean circulation and the ecology of the region. Researchers have seen a marked slowdown in North Atlantic circulation as cold, fresh water off Greenland’s southern tip has acted as a roadblock to the currents that steer water through the region. That has the potential to mess with ocean circulation as well as weather patterns, particularly in Europe.
The changes in the Arctic are a harbinger of what’s in store for the planet if we continue to emit carbon pollution. Some of these changes are likely irreversible. But the report does note that if the world sticks to its goal in the Paris Agreement, the region could reach an equilibrium that while different from its present state, is still less radical than the fate it faces if we keep going down the current carbon path.
Nearly 4 million square kilometers of frozen soil — an area larger than India — could be lost for every additional degree of global warming experienced, warn scientists. Global warming will thaw about 20% more permafrost than previously thought, they add – potentially releasing significant amounts of greenhouse gases into the Earth’s atmosphere. But these investigators also suggest that the huge permafrost losses could be averted if ambitious global climate targets are met.
…Permafrost is frozen soil that has been at a temperature of below 0ºC for at least two years. Large quantities of carbon are stored in organic matter trapped in the icy permafrost soils. When permafrost thaws the organic matter starts to decompose, releasing greenhouse gases such as carbon dioxide and methane which increase global temperatures.
It is estimated that there is more carbon contained in the frozen permafrost than is currently in the atmosphere. Thawing permafrost has potentially damaging consequences, not just for greenhouse gas emissions, but also the stability of buildings located in high-latitude cities.
Roughly 35 million people live in the permafrost zone, with three cities built on continuous permafrost along with many smaller communities. A widespread thaw could cause the ground to become unstable, putting roads and buildings at risk of collapse. Recent studies have shown that the Arctic is warming at around twice the rate as the rest of the world, with permafrost already starting to thaw across large areas.
The study suggests that permafrost is more susceptible to global warming that previously thought, as stabilising the climate at 2ºC above pre-industrial levels would lead to thawing of more than 40% of today’s permafrost areas.
..Co-author Dr Eleanor Burke, from the Met Office Hadley Centre, said: “The advantage of our approach is that permafrost loss can be estimated for any policy-relevant global warming scenario. “The ability to more accurately assess permafrost loss can hopefully feed into a greater understanding of the impact of global warming and potentially inform global warming policy.”
S. E. Chadburn, E. J. Burke, P. M. Cox, P. Friedlingstein, G. Hugelius, S. Westermann. An observation-based constraint on permafrost loss as a function of global warming. Nature Climate Change, 2017; DOI: 10.1038/nclimate3262
The Arctic sea ice maximum extent and Antarctic minimum extent are both record lows this year. Combined, sea ice numbers are at their lowest point since satellites began to continuously measure sea ice in 1979.…”There’s a lot of year-to-year variability in both Arctic and Antarctic sea ice, but overall, until last year, the trends in the Antarctic for every single month were toward more sea ice,” said Claire Parkinson, a senior sea ice researcher at Goddard. “Last year was stunningly different, with prominent sea ice decreases in the Antarctic. To think that now the Antarctic sea ice extent is actually reaching a record minimum, that’s definitely of interest
Arctic sea ice hit a record low wintertime maximum extent in 2017. At 5.57 million square miles, it is the lowest maximum extent in the satellite record, and 455,600 square miles below the 1981 to 2010 average maximum extent.
Credit: NASA Goddard’s Scientific Visualization Studio/L. Perkins
These are some of the words that describe what’s been happening in the Arctic over the past year as surge after surge of warm air have stalled, and at times reversed, sea ice pack growth. And the unfortunate string of superlatives is set to continue this week.
Arctic sea ice is already sitting at a record low for this time of year and a powerful North Atlantic storm is expected to open the flood gates and send more warmth pouring into the region from the lower latitudes. By Thursday, it could reach up to 50°F above normal. In absolute temperature, that’s near the freezing point and could further spur a decline in sea ice….
…A massive storm is swirling toward Europe. It’s a weather maker in itself, churning up waves as high as 46 feet and pressure dropping as low as is typical for a Category 4 hurricane as of Monday. The storm is to the southeast of Greenland and its massive comma shape has made for stunning satellite imagery. The storm is expected to weaken as it approaches Europe, but it will conspire with a high pressure system over the continent to send a stream of warm air into the Arctic through the Greenland Sea.
Temperatures are forecast to reach the melting point in Svalbard, Norway, an island between the Greenland and Karas Seas. The North Pole could also approach the melting point on Thursday.