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News Article | February 14, 2017
Site: www.theguardian.com

Sea ice around Antarctica has shrunk to the smallest annual extent on record after years of resisting a trend of manmade global warming, preliminary US satellite data has shown. Ice floating around the frozen continent usually melts to its smallest for the year towards the end of February, the southern hemisphere summer, before expanding again as the autumn chill sets in. This year, sea ice extent contracted to 883,015 sq miles (2.28m sq km) on 13 February, according to daily data from the US National Snow and Ice Data Center (NSIDC). That extent is a fraction smaller than a previous low of 884,173 sq miles recorded on 27 February 1997 in satellite records dating back to 1979. Mark Serreze, director of the NSIDC, said he would wait for a few days’ more measurements to confirm the record low. “But, unless something funny happens, we’re looking at a record minimum in Antarctica,” he told Reuters. “Some people say it’s already happened. We tend to be conservative by looking at five-day running averages.” In many recent years, the average extent of sea ice around Antarctica has tended to expand despite the overall trend of global warming, blamed on a build-up of greenhouse gases in the atmosphere, mainly from burning fossil fuels. People sceptical of mainstream findings by climate scientists have often pointed to Antarctic sea ice as evidence against global warming. Some climate scientists have linked the paradoxical expansion to shifts in winds and ocean currents. “We’ve always thought of the Antarctic as the sleeping elephant starting to stir,” Serreze said. “Well, maybe it’s starting to stir now.” World average temperatures climbed to a record high in 2016 for the third year in a row. Climate scientists say warming is causing more extreme days of heat, downpours and is nudging up global sea levels. At the other end of the planet, ice covering the Arctic Ocean has been at repeated lows in recent years. In the northern winter, sea ice expands and is at its smallest extent for mid-February, at 5.38m sq miles.


News Article | February 15, 2017
Site: www.sej.org

"Sea ice around Antarctica has shrunk to the smallest annual extent on record after years of resisting a trend of man-made global warming, preliminary U.S. satellite data showed on Tuesday. Ice floating around the frozen continent usually melts to its smallest for the year around the end of February, the southern hemisphere summer, before expanding again as the autumn chill sets in. This year, sea ice extent contracted to 2.287 million square kilometers (883,015 square miles) on Feb. 13, according to daily data from the U.S. National Snow and Ice Data Center (NSIDC)."


Antarctic sea ice is now at its lowest extent since record-keeping on the subject began in 1979, based on preliminary satellite data from the US National Snow and Ice Data Center (NSIDC). Sea ice extent in Antarctica typically reaches its low point for the year towards the end of February, before the Southern Hemisphere begins heading into autumn and sea ice extent begins growing again. As of February 13th, though, sea ice extent in Antarctica totaled only 2.287 million square kilometers (883,015 square miles) — making for a new record low extent. (February 14th apparently then saw a lower extent, 2.224 million square kilometers.) The previous record low Antarctic sea ice extent of 2.290 million square kilometers (884,173 square miles) occurred around February 27, 1997. The news is noteworthy as until very recently “climate change deniers” have used Antarctic sea ice extent (which was fairly stable in recent times) as an argument against the existence of recent and ongoing global temperature rise (lazy, and unconvincing to those who aren’t just looking for a cheap shot, but it was used this way nonetheless). “It’s a new record, and it might actually go a little bit further south yet this summer,” commented Jan Lieser, a marine glaciologist with the Antarctic Climate and Ecosystems Cooperative Research Centre in Hobart. Here’s more from the Sydney Morning Herald: “In the south, each day this summer the extent of frozen sea has been the lowest recorded for that date since 1979, when satellite data was first collected. “Dr Lieser said the lowest extent to date was last Tuesday, when it fell to 2.224 million square kilometres — an area roughly the size of Tasmania less than the previous low in 1997. It comes just two years after scientists reported a record high ocean sea ice extent. “He said a fall in sea ice coverage brings a feedback effect. White ice reflects heat, but darker water absorbs it. Whenever there is less sea ice, more heat goes into the ocean, delaying freezing the following winter and likely contributing to a further reduction over time.” While future fluctuations are to be expected, rather than there simply being a yearly decrease in extent for the foreseeable future, the new record does seem to suggest that sea ice in Antarctica is now on a terminal decline. Buy a cool T-shirt or mug in the CleanTechnica store!   Keep up to date with all the hottest cleantech news by subscribing to our (free) cleantech daily newsletter or weekly newsletter, or keep an eye on sector-specific news by getting our (also free) solar energy newsletter, electric vehicle newsletter, or wind energy newsletter.


In December, doctor Tom Barker, 64, was swept more than 200 yards in an avalanche that left him buried under 9 feet of snow, after he and a friend skied into a closed area at the Mt. Rose ski resort near Lake Tahoe without their avalanche-safety gear. Barker did not survive. Slides kill one or two winter-wilderness travelers every couple of years in the Sierras around Lake Tahoe. For every death, avalanche experts say, about 10 people are caught in a cascade of snow and ice and barely escape with their lives. As the backcountry becomes an increasingly popular winter destination - activities outside the bounds of ski resorts rose 21 percent in the U.S. last winter, according to Snowsports Industries America - the likelihood of tragedy has grown. That popularity, and the risk, are driving companies to develop new avalanche-safety products based on bleeding-edge technology better known in the fast-evolving realms of self-driving cars, the internet of things, and big-data computing. The technology holds promise for preventing fatalities, according to experts, but it's in its infancy. "Everyone wants the avalanche goggles that you can just look everywhere and see whether it's safe or not - I don't think we're ever going to get there," said Jeffrey Deems, a research scientist at the National Snow and Ice Data Center in Colorado. "But we can start to create new observations that help us get a better view of how the snowpack varies across the terrain." One method for making those observations uses Lidar, the laser-based system used by some self-driving cars to gauge distance. With this equipment, avalanche forecasters can measure the snow depth at a known avalanche starting point - one of the best but most dangerous spots for assessing slide risk - from more than 1,000 yards away, Deems said. Without Lidar, judging the snowpack in an avalanche zone involves measuring it elsewhere and estimating depth at the starting point, he said. "There's quite a lot of uncertainty associated with that," Deems said. "This new technology allows us to really see the pattern of snow accumulation." Another relatively new high-tech tool for predicting avalanches is a "smart" probe by Mountain Hub that's inserted into the snowpack and uses built-in pressure and depth sensors to identify problematic layers, such as ice from which the snow on top could slide, or large crystals that could crumble under pressure, leading to the same result. Information on snow layers can be uploaded to a database to help avalanche forecasters track the presence of weak or slippery sheets buried across a landscape. However, while new developments in avalanche-safety tech such as the smart probe and Lidar may pay off in saved lives in the future, they're not all that useful yet, argued Brandon Schwartz, lead avalanche forecaster for the Sierra Avalanche Center, a nonprofit partner of the U.S. Forest Service, which puts out daily slide-hazard bulletins. The Lidar system, at about $200,000, is prohibitively expensive for many forecasters whose agencies rely on government funding and donations as well as for many safety teams that use explosives to blast potential avalanche areas near highways, railroads and in ski resorts to create controlled slides, Schwartz said. And that system can't reveal the level of detail in the snowpack's layering that Schwartz and his colleagues need, he said. Mountain Hub's probe, the $1,500 Avatech SP2, has accuracy issues and "is not that great, unfortunately," Schwartz said. "It's not really there yet as a tool that has enough worth to be in widespread use." Both systems have potential to evolve and prove useful for analyzing the snowpack and producing large data sets that could add detail and scale to the forecasting process, Schwartz added. Mountain Hub marketing director TJ Kolanko acknowledged the SP2's deficiencies, but said the company was working to improve its technology. This fall, it plans to launch the consumer-oriented Avatech Scope, a "smart" ski pole that has a pressure sensor in the tip and a depth sensor on the shaft. The gadget will cost $499 and will come with a second, standard ski pole. As the Scope is pushed into the snow, the pressure sensor measures hardness and sends the data through an algorithm that translates it into types of snow layers, while the other sensor tracks the depth, to build a virtual picture of the snowpack. This is where the big-data analysis beloved across today's business world comes in, along with the internet of things. Information collected by individual users, who can easily perform multiple assessments in a number of locations, will be uploaded to the Mountain Hub platform. There, it can be analyzed in conjunction with data about snowpack conditions, weather and avalanche activity to predict avalanche hazard through a crowd-sourced "culture of contribution," Kolanko said. Still, as promising as the new avalanche forecasting technologies may be, traditional tools, including beacons, probes and shovels, and training in skills such as snowpack testing and forecast analysis remain vital to help prevent tragedies, experts say. In January, for example, an avalanche caught pro extreme skier JT Holmes in the Tahoe wilderness between the resorts of Squaw Valley and Sugar Bowl, carried him over a 30-foot cliff and buried him face down, 6 feet under. Four companions located him by the signal of his safety beacon and dug him out. He was back on his skis minutes later. Avalanche-safety instructor John Littleton of Alpine Skills International in Truckee said more often than not when he's in the backcountry he encounters people without proper safety skills and gear. "The human element just assumes that, 'We're going to be safe,'" said Littleton. "Get the education and get the equipment."


News Article | February 16, 2017
Site: www.eurekalert.org

Researchers have completed the first flights of a NASA-led field campaign that is targeting one of the biggest gaps in scientists' understanding of Earth's water resources: snow. NASA uses the vantage point of space to study all aspects of Earth as an interconnected system. But there remain significant obstacles to measuring accurately how much water is stored across the planet's snow-covered regions. The amount of water in snow plays a major role in water availability for drinking water, agriculture and hydropower. Enter SnowEx, a NASA-led multi-year research campaign to improve remote-sensing measurements of how much snow is on the ground at any given time and how much water is contained in that snow. SnowEx is sponsored by the Terrestrial Hydrology Program at NASA Headquarters in Washington, D.C., and managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland. The first year of the ground and air campaign takes place in February in western Colorado. "This is the most comprehensive campaign we have ever done on snow," said Edward Kim, a remote sensing scientist at NASA Goddard and the SnowEx project scientist. "An army of nearly 100 scientists from universities and agencies across the U.S., Europe and Canada are participating. Our goal is to find and refine the best snow-measuring techniques and how they could work together." Scientists know that they will need multiple sensors to measure the water content in snow. "No one instrument is perfect," said Charles Gatebe from NASA Goddard, SnowEx deputy project scientist and senior scientist with Universities Space Research Association. "One of our biggest problems is detecting snow through trees. We will work closely with our ground team to try new techniques to see if we can figure out how to do that accurately." More than one-sixth of the world's population relies on seasonal snow for water. In the western U.S., nearly three-quarters of the annual streamflow that provides the water supply arrives as spring and summer melt from the mountain snow packs. Right now, predictions of streamflow can vary widely due to limited ground measurement sites. This is one of the reasons scientists and resource managers are interested in a comprehensive view from space of what they call snow-water equivalent -- the amount of liquid water contained in snow cover. Scientists use snow-water equivalent to estimate the amount of water that will melt into mountain streams, rivers and reservoirs. Snow also effects and is affected by the climate. Scientists have detected changes in snow quantity and snowmelt timing that track with other changes prompted by Earth's warming climate. While satellites are not able to measure snow-water equivalent accurately over all snowy landscapes, satellites have monitored the extent of seasonal snow-covered areas for decades. Since 1967, Northern Hemisphere spring snow cover has declined by about 1 million square miles. Loss of snow cover results in Earth absorbing more sunlight, accelerating the planet's warming. In the air, on the ground The instruments and techniques developed in campaigns such as SnowEx could one day result in a snow-observing space mission. "We will also figure out a better way to optimize the use of existing satellites to make measurements," said Jared Entin, program manager of the Terrestrial Hydrology Program at NASA Headquarters. Five aircraft with a total of 10 different sensors are part of the SnowEx campaign. From an operations base at Peterson Air Force Base, Colorado Springs, SnowEx will deploy a P-3 Orion aircraft operated by the Scientific Development Squadron ONE (VXS-1), stationed at the Naval Air Station Patuxent River, Maryland. High-altitude NASA jets will fly from NASA's Johnson Space Center in Houston, and NASA's Armstrong Flight Research Center in Palmdale, California. A King Air and a Twin Otter will fly out of Grand Junction, Colorado. The planes will carry one passive and four active microwave sensors that are good at measuring snow-water equivalent in dry snow, but are less optimal for measuring snow in forests or light snow cover; a thermal infrared camera and a remote thermometer (KT-15) for measuring surface temperature; laser instrument that it good at measuring snow depth and snow water equivalent through trees; an imaging spectrometer which measures snow albedo -- the amount of sunlight reflected and absorbed by snow, which controls the speed of snowmelt and the timing of its runoff. The King Air carries the Airborne Snow Observatory from NASA's Jet Propulsion Laboratory in Pasadena, California. ASO is the first remote sensing system to ever measure snow depth, snow water equivalent and snow albedo across entire mountain basins, and has uniquely quantified snow water equivalent over mountainous regions since 2013. The field portion of the campaign is based in Grand Mesa and Senator Beck Basin. Scientists will use measurement and sampling procedures that will allow the team to validate the remotely-sensed measurements acquired by the multiple sensors on the various aircraft. Traditional and high-tech equipment is being used for the ground campaign, including snow pits and remote sensing instruments hoisted 40 feet in the air on boom trucks. "The big challenge to the ground campaign is collecting high-quality field measurements while keeping everyone safe and healthy in these harsh environments," said Kelly Elder, research hydrologist with the U.S. Forest Service's Rocky Mountain Research Station, Fort Collins, Colorado, who is leading the overall ground campaign. Scientists will be working above 10,000 feet in potentially windy and freezing conditions up to 10 hours a day. They need snow goggles or sunglasses to protect their eyes. Hypothermia is a very real threat, so researchers wear special clothing designed to wick away sweat and keep them dry. The teams use snowshoes, skis and snowmobiles to access the ground measurement locations on Grand Mesa and Senator Beck Basin. The Senator Beck Research Basin study area is near the headwaters of the Rio Grande River Basin. "Its research areas are the first major mountain systems downwind of the desert Southwest and Colorado Plateau, making it an ideal place to study the effects of dust on snowmelt," said Hans-Peter Marshall, of Boise State University, who is leading ground operations in Senator Beck Research Basin. "Grand Mesa was chosen for its flatness and range of forest conditions," said Chris Hiemstra, a research physicist with the U.S. Army Corps of Engineers, and the lead for the Grand Mesa ground operations. The variety of terrain and environments make the ground sites good models for developing global measurements of snow. Ground equipment was installed in September 2016, before snow started to fall. A ground site near a campground will host specialized equipment too large to move around. This Local Scale Observation Site effort is led by Ludovic Brucker from NASA Goddard. Teams of 50 researchers are making ground measurements, rotating in and out of the field every week over a three-week period. Data acquired from the SnowEx campaign will be stored at the National Snow and Ice Data Center in Boulder, Colorado, and will be available to anyone at no cost, as is the case with all NASA data. After the field work, SnowEx scientists will analyze data and recommend to NASA how to proceed in the next few years. "This campaign will generate the best ideas from the global community of snow experts," Kim said. Senator Beck Basin is managed by the Center for Snow and Avalanche Studies CSAS, a non-profit organization that hosts research studies on snowpack at the basin.


News Article | February 24, 2017
Site: www.techtimes.com

Obstacles to determine how much water is locked up in the world's mountain snow have yet to be conquered. No single instrument, even the space-based, had ever come close to hurdle it. Against this backdrop, NASA's SnowEx has joined the fray with a goal — to find the best snow-measuring techniques. "This is the most comprehensive campaign we have ever done on snow," declared Edward Kim, a remote sensing scientist at NASA Goddard and the SnowEx project scientist. Seventy percent of the world's surface is covered by water of which only 2.5 percent of this is fresh water. Of the available fresh water, more than two-thirds are locked in glaciers. In addition, about 20 percent of the Earth's land surface is covered by snow land, which also has water locked in it. This has far-reaching consequences on a society where more than a billion people depend largely on snow for their fresh water, Kim said. The water locked in the world's mountain snow has other consequences for people, such as devastating floods, drought, and instability when its supply is scarce. It is said some 663 million people worldwide have no access to drinking water. Snow packs that melt, for instance, provided a major supply to the annual streamflow in the western United States when spring and summer arrive. Yet there is no information available, at present, how much water will pour out from melting snow owing to inadequate ground measurement sites. This situation has led to the birth of SnowEx. Scientists and resource managers wanted to have a comprehensive view from space the amount of water contained in the snow-covered land that will eventually melt into streams, rivers, and reservoirs. The snow-covered mountains of Colorado were combed by aircraft with sensors as researchers have completed the first flights of the SnowEx campaign this month. The NASA-led experiment uses five aircraft with 10 sensors with a goal to find the right combination to develop instruments and techniques which could be used in a snow-observing space mission in the future. "We will also figure out a better way to optimize the use of existing satellites to make measurements," Jared Entin of the Terrestrial Hydrology Program at NASA said. Multiple sensors are needed to address the difficulty in measuring water content in snow including those under the canopies. "We will work closely with our ground team to try new techniques to see if we can figure out how to do that accurately," said Charles Gatebe from NASA Goddard, SnowEx deputy project scientist and senior scientist with Universities Space Research Association. The Terrestrial Hydrology Program at NASA Headquarters in Washington, D.C. sponsored SnowEx while NASA's Goddard Space Flight Center in Greenbelt, Maryland managed the multi-year campaign. Storage of data generated from the campaign will be at the National Snow and Ice Data Center in Boulder, Colorado and will be accessible to all. The campaign is expected to "generate the best ideas from the global community of snow experts," Kim said. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.


News Article | January 19, 2017
Site: www.techtimes.com

Scientists have reported that 2016 is the hottest year on Earth since record keeping started in 1880 — and it is the third year in a row to set a new record for average global temperatures. The average temperatures last year were the highest recorded since over 130 years ago: 1.78 degrees Fahrenheit above the 20th-century average according to NASA, and 1.69 degrees Fahrenheit above the same period’s average according to the National Oceanic and Atmospheric Administration. These recorded temperatures “continue a long-term warming trend,” scientists from NASA said in a statement. Across Earth too, there was not a single land area that enjoyed lower-than-average temperatures last year, warned NOAA. The year 2016, in fact, marked the third consecutive warmest year on record globally, with the months from January to August emerging as the warmest on record. "This was the third year in a row in our analysis to set a new record. That happened only once before in our record, and that was in the years 1939 through 1941, which now don't even fit in the top 30 [warmest years] of the record,” explained Deke Arndt, global monitoring chief at NOAA’s National Centers for Environmental Information, at a press briefing. The poles felt the brunt of this warming trend, with the estimated average yearly sea-ice extent last year in the Arctic appearing to be the lowest annual average on data. It was 3.92 million square miles, the National Snow and Ice Data Center revealed. The Arctic was nearly 7.2 degrees Fahrenheit hotter last year than in preindustrial period, a “very large change” according to Goddard Institute for Space Studies director Gavin Schmidt. The El Niño phenomenon, a climate cycle marked by abnormally warm temperatures in the Pacific, raged through 2015 and 2016 and contributed to the record temperatures. Phenomena such as El Niño or La Niña warm or cool the upper tropical Pacific Ocean and result in corresponding global wind and weather pattern variations. However, 90 percent of the warming was because of human activity, primarily via greenhouse gas emissions, Schmidt said further. The scientists used global climate models to probe how various factors such as solar changes, volcanic impacts, changes in Earth’s orbit, and man-made effects such as greenhouse gases played a part in climate change. They analyzed not just surface air temperatures but also the data from the upper atmosphere, stratosphere, and deep ocean. What they discovered: the natural factors’ contribution to the record heat is so close to zero, with the long-term trend being seen today surfacing as the consequence of human activity. It’s dominantly the climb in greenhouse gas emissions, particularly carbon dioxide, Schmidt added. Tech Times previously reported that in the United States, 2016 ranked second warmest in records dating back 1895, with every single state and city in the Lower 48 states getting warmer than usual last year. Average temperature in the country last year was 54.9 degrees Fahrenheit, which was nearly 3 degrees higher than long-term average. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.


News Article | February 16, 2017
Site: www.techtimes.com

Amidst soaring concerns over the rising temperatures at unheard levels in the range of 20°C plus (36°F) at the North Pole, the Arctic area is hogging greater scientific attention with many plans floating on how to stem the erosion of sea ice. The latest contingency plan seeks to 'refreeze' the Arctic by installing 10 million wind-powered pumps that will spray sea water to the surface of the sea ice for replenishing and reinforcing thickness during winter. "Thicker ice would mean longer-lasting ice. In turn, that would mean the danger of all sea ice disappearing from the Arctic in summer would be reduced significantly," said Steven Desch who is the lead researcher and Arizona State University physicist. Calling for proactive action to restore ice than preaching restraint to stop emission, the scientist noted that by merely telling people not to burn fossil fuels will not work. "Our only strategy at present seems to be to tell people to stop burning fossil fuels," added Desch. The project has been published in Earth's Future. The cost of adding 10 million pumps has been worked out to be $500 billion. The scientists argue that the current loss of ice is twice the rate predicted a few years ago and the 2015 Paris climate agreement is inadequate in checking the region's sea ice from total vanishing by 2030. According to environmentalists, if Arctic sea ice cover is lost completely, then the consequences would be far-reaching and may affect many species — including Arctic cod and polar bears — and finish its rare habitat. The removal of ice will also take away the buffer that deflects solar radiation and hasten the melting of permafrost and push many greenhouse gasses into the atmosphere. Other projects to stem sea-ice loss include whitening of Arctic by spraying light-colored aerosol particles to reflect solar radiation and pumping of seawater into the atmosphere to make clouds reflect sunlight away from the surface. Despite the costly nature of these imaginative projects, the fact that they are being considered shows the level of anxiety prevailing among scientists on the Arctic's ice loss. "The situation is causing grave concern," said Professor Julienne Stroeve from the University College London. According to the U.S. National Snow and Ice Data Center in Boulder, the coverage of Arctic's sea ice in January at 13.38 million square km has been the lowest ever in four decades after the satellite tracking of the polar region started. Scientists are expecting the complete loss of sea ice in Arctic by 2030 if the current rate of emission persists. Meanwhile, Arctic pollution is also hogging the limelight. A team of researchers from Germany wrote in Deep Sea Research about the scale of polar pollution. In the paper, Mine K. Tekman of the Alfred Wegener Institute expressed surprise at the bulging garbage washed up in the Arctic despite its far-flung location. Their study tracked garbage growth from 2002 to 2014, especially the menace of growth in small plastic waste. The team watched litter at two stations between Greenland and Svalbard under the AWI deep-sea observatory network and noticed how receding Arctic sea has been augmenting the influx of tourism and shipping into the area. After imaging 2,500 meters of depth, the team observed that 3,485 pieces of litter per square kilometer had grown to 6,333 by 2014. The report noted the "current waste management frameworks are inadequate" in handling the problem of marine litter pollution. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.


News Article | February 16, 2017
Site: www.washingtonpost.com

In recent years, one of climate change doubters’ favorite arguments has involved the floating sea ice around Antarctica. It’s growing, they contended — and that raises doubts about our understanding of human-induced climate change. To this, climate scientists always responded: Not so fast. Floating sea ice in another cold place, the Arctic, is clearly shrinking, as are Arctic and Antarctic glaciers, and we don’t fully understand all the drivers behind the vast and complex Antarctic sea ice system. So don’t leap to the conclusion that odd behavior in floating Antarctic ice, which indeed has been growing slightly in recent years, undermines climate concerns. Now, though, the argument for doubters just got even more complicated. After seeing a record high for total extent in the year 2014, Antarctic sea ice had been running very low in late 2016 and early 2017. And now, as of data recorded on Monday and Tuesday by the National Snow and Ice Data Center, the extent of Antarctic sea ice now appears to have hit a record low (although scientists still have to confirm this and have not made an official announcement yet). It’s summer in Antarctica right now, and floating sea ice on Monday only covered 2.287 million square kilometers, according to “near-real-time data” from the National Snow and Ice Data Center. If that’s correct, that would barely edge out the previous record low of 2.290 million square kilometers on Feb. 27, 1997. The records go back to 1979. On Tuesday, meanwhile, the ice extent shrank further down to 2.259 million square kilometers — underscoring the likelihood of a record, once the data is confirmed. Here’s an image, created using the center’s handy “Charctic” tool, showing this month’s ice (in light blue, below the others) compared with all other years in which we have data for Antarctic sea ice: “Record low sea ice extent in the Arctic has, in a sense, become old news,” said Mark Serreze, director of the National Snow and Ice Data Center. “But now the Antarctic is getting into the act.  There are certainly many questions out there as to why Antarctic sea ice is also at a record low, but we can’t deny the reality that things are changing and they are changing fast.” Sea ice is almost completely absent right now along the coast of West Antarctica in particular, a region where huge and fast-retreating glaciers have raised major concerns about potential sea-level rise. It’s unclear if lack of sea ice in the area might also signal that the oceans are having an effect on the continent’s marine-based glaciers. It’s also important to note that it’s still only mid-February, so it could be that Antarctic sea will lose more ice before it begins to refreeze and expand again, according to its seasonal cycle. So what now appears to be a new record low may not be the record for very long. We will have to await a formal confirmation of all of this from the center, which may not come until the ice is clearly beginning to grow once again. In the meantime, there are some interesting ideas out there about what explains the recent behavior of Antarctic sea ice. For instance, Gerald Meehl, a climate scientist at the National Center for Atmospheric Research in Boulder, Colo., has published research suggesting that floating Antarctic ice is actually controlled in part by the state of the distant Pacific Ocean, whose influence on wind and weather patterns ultimately stretches all the way down to the Antarctic. That study focused on a natural climate wobble called the Interdecadal Pacific Oscillation, or IPO, whose negative phase is one in which heat ends up getting buried in the Pacific Ocean, and whose positive phase unleashes it. The IPO was in a negative phase through much of the 2000s, but it may now be shifting back, Meehl says. And that could be playing a role in sea ice. “It is consistent that a positive phase of the IPO could be associated with reduction of Antarctic sea ice extent, which is what is happening now,” Meehl commented by email. “However, given that the IPO is a decadal timescale phenomenon, and what we’re seeing now is a reduction of Antarctic sea ice that started sometime after the middle of 2016, we can’t say that Antarctic sea ice will stay at this low extent indefinitely. But the evidence from IPO connections is pointing in the right direction for a possible decadal trend toward reduced sea ice extent.” In the end, since Antarctic sea ice was previously trending upward, the sudden reversal shouldn’t be a reason to turn on a dime and suggest that the ice is now declining — yet. Instead, it further underscores that we don’t fully understand what’s going on with this system. Which is precisely why it’s so dangerous to cite Antarctic ice to undermine the overwhelming evidence of climate change elsewhere. More from Energy and Environment: The West’s largest coal-fired power plant is closing. Not even Trump can save it. Hundreds of current, former EPA employees urge Senate to reject Trump’s nominee for the agency The Endangered Species Act may be headed for the threatened list For more, you can sign up for our weekly newsletter here and follow us on Twitter here.


There’s no mistaking it now. Even though we don’t have the final numbers, it is abundantly clear that the sea ice ringing the Antarctic continent has fallen precipitously — reaching a record low just a few short years after it reached a record high. In 38 years of records dating back to 1979, the sea ice lows seen as of the end of February 2017 — a time of year when ice in the Antarctic is at its annual minimum — are unprecedented. The area of ocean covered by sea ice still appears to be shrinking, but as of Feb. 28, there were just 2.131 million square kilometers of floating ice surrounding Antarctica, according to near-real time data provided by the National Snow and Ice Data Center. That’s much less than the prior low of 2.29 million square kilometers on Feb. 27, 1997. The difference — about 159,000 square kilometers, or 61,390 square miles — amounts to an area nearly as large as Florida. Here’s what 2017 (the light blue line) looks like when you compare it with the other four lowest years in the record (1984, 1993, 1997 and 2011), based on the helpful “Charctic” tool offered by the National Snow and Ice Data Center: The data here are reported as a five-day average and should not be considered final — there could still be adjustments. And the ice could go lower before it rebounds as colder temperatures begin to return to the Antarctic. Still, the margin is large enough that a record is unavoidable, says Mark Serreze, director of the National Snow and Ice Data Center, although he said his group will wait to call one formally until they’re sure an annual minimum has been reached and the ice is growing again. “It’s going to be a record low minimum no matter what happens right now, it’s just a matter of, how low do we go,” Serreze said Monday. “It could be any day now.” (The ice is even lower now than it was when we spoke.) Far more difficult than pinpointing the actual ice extent is the question of why this is happening. The simple fact that the previous record low was in 1997, 20 years ago, “really goes to show you how variable the system is down there,” Serreze said. Indeed, the overall Antarctic sea ice trend, bucking climate change expectations, has been a slight increase over time, rather than a shrinkage. All of that said, 2017 is a year that looks like what we ought to expect on a warming planet based on climate models, said Cecilia Bitz, an expert on sea ice at the University of Washington in Seattle. The confusing thing, she continued, is that other recent years have not matched the expectations created by those models at all. As mentioned earlier, before this most recent crash, Antarctic sea ice reached a record high in October 2014. This is one reason that, until recently, climate change skeptics loved to point to Antarctic sea ice behavior to justify their rejection of mainstream climate science — something I highlighted two weeks ago when the current Antarctic record was already beginning to emerge. The story for Antarctic ice this year, Bitz said, can’t be understood unless we look back to September and October, when ice levels were relatively normal but suddenly plunged. It was the loss then that exposed the ocean to 24-hour sunlight in the austral summer, helped it warm up and ultimately set in motion the record we’re now seeing. “We went from really typical conditions to record low in a two-month period, so I think that’s when we should be focusing,” Bitz said of the months in late 2016. Here’s a figure she provided, showing that Antarctic ice extent looked fairly normal throughout much of 2016, but then steeply plummeted at the end of the year, with particularly anomalous low levels of ice in November and December: The cause at that time, Bitz said, was an incursion of warm air from the north into multiple parts of the Antarctic. What drove down the warm air, though, is another matter. One leading idea to explain what’s happening with Antarctic sea ice, advanced in a paper by Bitz and Gerald Meehl of the National Center for Atmospheric Research (and several colleagues), targets changes in the Pacific Ocean to explain the unexpected expansion of Antarctic sea ice between 2000 and 2014 — a trend that ran contrary to climate model projections. This study suggests the expansion was a fluke of natural variability in the world’s largest ocean, which changed the atmosphere in ways that affected winds all the way down in the Antarctica (if winds blow floating sea ice outward from the continent, more ice can then fill the empty space, and Antarctic ice as a whole expands). But Meehl has cautioned that the cycle in question, the Interdecadal Pacific Oscillation, plays out over decades, making it hard to be sure yet whether a turn in this cycle will correspond to Antarctic ice shrinkage. Bitz, too, said she is cautious for now about seizing on this explanation, noting that the sharp loss in Antarctic ice lagged behind a positive peak in the IPO by six to nine months, raising doubts about the connection. But you can bet that scientists are going to spend plenty of time trying to take this question apart — and that the analysis has just begun.

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