Skip to main content

Home/ Climate Change Impacts Inventory/ Group items tagged atmosphere

Rss Feed Group items tagged

Hunter Cutting

Upper atmosphere collapsing, threatening satellite comms - 0 views

  • CNN) -- An upper layer of Earth's atmosphere recently shrank so much that researchers are at a loss to adequately explain it, NASA said on Thursday. The thermosphere, which blocks harmful ultraviolet rays, expands and contracts regularly due to the sun's activities. As carbon dioxide increases, it has a cooling effect at such high altitudes, which also contributes to the contraction. But even these two factors aren't fully explaining the extraordinary contraction which, though unlikely to affect the weather, can affect the movement of satellites, researchers said. "This is the biggest contraction of the thermosphere in at least 43 years," John Emmert of the Naval Research Lab was quoted as saying in NASA news report.
  • The thermosphere lies high above Earth's surface, close to where the atmosphere ends and space begins. It ranges in altitude from 55 miles (90km) to 370 miles (600km) above the ground -- the realm of meteors, auroras, space shuttles and the international space station
  • The collapse occurred during what's known as a "solar minimum" from 2007 to 2009, during which the sun plunged into an unprecedented low of inactivity. Sun spots were scarce and solar flares were nonexistent, NASA reported.
  • ...5 more annotations...
  • Still, the collapse of the thermosphere was bigger than the sun's activity alone can explain. Emmert suggests that the increasing amounts of carbon dioxide making its way into the upper atmosphere might have played a role in the anomaly.
  • Carbon dioxide acts as a coolant in the upper atmosphere, unlike in the lower atmosphere, shedding heat via infrared radiation. As carbon dioxide levels build up on Earth, it makes its way into the upper levels and magnifies the cooling action of the solar minimum, Emmert said. As carbon dioxide gradually builds up, "we expect every solar minimum to be a little lower, and then this solar minimum comes along, but instead it's a lot lower. And that's pretty surprising," said Stanley Solomon, a senior scientist with the National Center for Atmospheric Research who wasn't directly involved in this research.
  • But, Emmert said, even taking into account the solar activity and carbon dioxide buildup doesn't fully account for this abnormal collapse. Despite the puzzling anomaly, the collapse of the thermosphere is unlikely to have a direct effect on our daily lives, said Solomon. "It's not going to affect the weather, or you won't be able to tell that this is going on by looking at the sky. It's not going to look any darker," he said.
  • But the contraction of the thermosphere can affect the drag on satellites and space junk orbiting at those levels. "Debris that's up there stays up longer. The amount of orbital debris is a concern for space navigation. There is concern that space debris is building up," Emmert said. The abnormal change in the thermosphere may also affect other layers of the atmosphere, and though less certain, can result in slight disruptions of satellite communications, including global-positioning system signals, Solomon said. Emmert said there were still other possibilities unaccounted for that could have contributed to this phenomenon.
  • "It could be that we're underestimating the effects [of carbon dioxide] somehow. It could be because there were some physics that we're missing in the region of the atmosphere below the thermosphere, which quickly affects the thermosphere," he said. The researchers say they will continue to monitor the upper atmosphere, which is already rebounding. "So we're probably going to work in the next couple of years to try and unravel this," Emmert said.
Hunter Cutting

Atmospheric shift due to warming reducing drag on satellites - 0 views

  • Space buffs know that Earth orbit is littered with junk, including defunct satellites, spent rocket boosters, and other random debris--about 11,500 objects bigger than 4 inches across
  • every one of these speeding bits of hardware could potentially damage, or even smash up a working satellite. The latter could create a lot more debris, potentially triggering something called the Kessler Syndrome, in which fragments of a smashed satellite go on to smash more satellites, creating fragments that go on to smash more...and so on.
  • turns out that if you warm the lower atmosphere by trapping infrared radiation--the essence of the greenhouse effect--the upper atmosphere should actually get cooler.
  • ...2 more annotations...
  • That's already been observed
  • Anyway, a new analysis out of the University of Southampton, in the U.K., points out that this cooling actually makes the upper atmosphere contract, removing some of the friction that eventually drags space junk back to Earth (and yes, believe it or not, there's a tiny bit of air in low-earth orbit, where the space junk problem is most acute). With less falling to Earth, there's more to slam into working satellites, the International Space Station and whatever else happens to be up there.
Hunter Cutting

Wind storms on the rise in Southwestern U.S. - 0 views

  • Turbulent weather blows into the Southwest
  • According to many scientists, our atmospheric system is in such a “hydrologic cycle” with water, vapor and energy responding to the increase in heat from the Earth just like a pot of water on the stove. And this boiling point has made for increasingly windy years around the Four Corners
  • “Climate models indicate that global warming could be responsible for our colder temperatures and blustery days,” said Chris Fox, former Environmental Sciences professor at the University of Maryland. Fox has been studying weather for more than 20 years and spent last summer in the Durango area. Fox predicted five years ago that the “next big factor we’d be dealing with would be the wind after observing changes and “connecting the dots.”
  • ...4 more annotations...
  • “In Colorado, we get our wind from the west,” he explained. “Canada gets its wind from the east. Where the wind belts rub against each other – it causes friction. As friction occurs, it creates waves in the atmosphere. Waves create frontal systems. These frontal systems are most noticeable during the change of seasons, which is also when we get our biggest storms, particularly in spring and fall.” Fox concluded that climate change is tipping the balance toward a battle of heat and cold. “Storms, created when frontal systems collide, are the atmosphere’s way of dealing with differences in temperature,” he said. “The atmosphere is attempting to balance the energy and equalize the temperature with the air going from high pressure to low pressure.” Fox added that cold air is now coming further south than it used to and warm air is going further north than usual. “Wind is air trying to equalize pressure,” he said. The scientist then used the analogy of a runner eating a big bowl of pasta. “If he then downs a Red Bull, there is more energy in the system to fuel his run,” he said. This pasta analogy goes beyond the college classroom and has a practical and local effect as well. It can be applied to the recent wind and dust storms that have wreaked havoc on Durango locals and tourists alike. Bayfield motorcyclist Jeff Gilmore had his windshield sandblasted as he headed into Flagstaff recently. “Semis were lined up on the side of the road,” he said. “Foot high sand drifts progressed across I-89 from Page to Flagstaff.” Although he pulled down his full-face helmet and shut all the vents, Gilmore was still pounded. “Sand stuck to my chapstick and the fine grit got in my mouth,” he said.
  • Carlotta Haber and her daughter were sent 100 miles out of their way while driving from Durango to Sedona a few weeks ago. Just before Holbrook, Ariz., on I-40 West, a sign read, “Highway closed 43 miles ahead due to dust storm.” “I couldn’t see the car in front of me and big tumbleweeds were rolling at the car,” she said. These anecdotes are directly in line with scientific findings. In fact, the National Center for Atmospheric Research in Boulder has formulated global climate models forecasting that “all weather will get more extreme.” Storms are stronger than 20 years ago, according to NCAR, as the research center is predicting more precipitation per storm event, despite its forecast for fewer overall storms. Tim Foresman, former director of the United Nations Environmental program, explained, “These conditions are exactly what caused this past winter’s heavy snows in the East and the recent flooding in Tennessee. One was an extraordinary winter precipitation event and the other was a spring precipitation event.”
  • While these conditions may feel like an anomaly, research indicates that they are the logical result of changing conditions. National Climatic Data Center statistics reveal that in the last 30 years, the temperature has risen an average of 2 degrees in the United States. Since 1975, the average temperature in Colorado has increased by 2.28 degrees. The only two states whose temperatures have risen more are Utah, with a 2.43 degree increase, and Arizon,a with 2.79 degrees. A NASA report corroborates these findings. The report states that the last 12 months have been the warmest in at least 1,000 years. Foresman added, “The meteorological forecasts are based on prior weather patterns and may not be accurate without considering changes under way due to a warming climate. Forecasts are based on seasonal models from the immediate past and may not be a good indicator of the future due to changing climatic conditions.” His expertise has been extremely valuable to his sister-in-law, who just purchased property and is building a home in Durango. Counseling her on what to expect in the near future due to the changing patterns, she modified her construction plans.
  • Having recently experienced a blizzard in May in Santa Fe, Foresman stated the obvious. “The systems are all out of whack,” he said. “We’re going to be in for some interesting times. We can put our heads in the sand, or we can prepare.” In closing, Foresman remarked that the windiest days could be ahead for the Four Corners and Southwest and offered local residents a piece of advice. “If you have shutters on your windows, I suggest you make sure they’re functional and not decorative,” he said. “The winds aren’t going to go away until you turn the heat down.” •
Hunter Cutting

Record sea surface temperatures driven by global warming - 0 views

  • In a Congressional briefing on 30 June 2010, hurricane expert Greg Holland of the National Center for Atmospheric Research (NCAR) said the potential for a disastrous 2010 hurricane season reflects not just natural variability but also climate change.  He explained that record high sea surface temperatures in the tropical Atlantic were one of the principal factors behind the dire forecast, and that rising atmospheric concentrations of greenhouse gases may account for roughly half of the anomalous warmth.  He warned that "we’re looking at potentially a doubling of major hurricanes in the next 20 to 30 years" as a result of global warming.  Holland, Director of NCAR's Earth System Laboratory, made his remarks as a member of a panel on Hurricanes and Oil Will Mix: Managing Risk Now. 
  • A month before the panel's briefing, the National Oceanic and Atmospheric Administration (NOAA) issued on 27 May its 2010 Atlantic Hurricane Season Outlook. NOAA said there was a 70% chance that the Atlantic hurricane season would see 14-23 named storms, 8-14 hurricanes, and 3-7 major hurricanes.
  • Among the factors underlying its outlook, NOAA cited warm Atlantic Ocean surface waters, which in May were for the fourth month in a row at record high temperatures for the month:  "Sea surface temperatures [SSTs] are expected to remain above average where storms often develop and move across the Atlantic. Record warm temperatures – up to four degrees Fahrenheit above average – are now present in this region."
  • ...3 more annotations...
  • "There has not been a seasonal forecast of 23 storms put out for this country before," said Holland.  Like forecasters from NOAA and elsewhere (see More pre-season predictions of a very active Atlantic hurricane season, at the WunderBlog for a summary of forecasts), Holland cited high SSTs as a principal factor underlying his assessment. The SSTs during the first month of the hurricane season did nothing to diminish concerns.  As the figure below indicates, high SSTs characterized the tropical Atlantic in June, with many areas again seeing record high temperatures for the month. 
  • "So what’s happening?" asks Holland.  "Well it’s a combination of global warming and natural variability."
  • This is consistent with research results published in Geophysical Research Letters on 29 April 2010.  In Is the basin-wide warming in the North Atlantic Ocean related to atmospheric carbon dioxide and global warming?, Chunzai Wang and Shenfu Dong of NOAA's Atlantic Oceanographic and Meteorological Laboratory, conclude that "both global warming and AMO [Atlantic multidecadal oscillation] variability make a contribution to the recent basin-wide warming in the North Atlantic and their relative contribution is approximately equal."
Hunter Cutting

"Warmer temperatures the new normal": NOAA - 0 views

  • Hot summers (and balmier winters) may simply be the new normal, thanks to carbon dioxide lingering in the atmosphere for centuries. This trend reaches back further than a couple of years. There have been exactly zero months, since February 1985, with average temperatures below those for the entire 20th century. (And those numbers are not as dramatic as they could be, because the last 15 years of the 20th century included in this period raised its average temperature, thereby lessening the century-long heat differential.) That streak—304 months and counting—was certainly not broken in June 2010, according to the U.S. National Oceanic and Atmospheric Administration (NOAA). Last month saw average global surface temperatures 0.68 degree Celsius warmer than the 20th-century average of 15.5 degrees C for June—making it the warmest June at ground level since record-keeping began in 1880.
  • Not only that, June continued another streak—this year, it was the fourth warmest month on record in a row globally, with average combined land and sea surface temperatures for the period at 16.2 degrees C. The high heat in much of Asia and Europe as well as North and South America more than counterbalanced some local cooling in southern China, Scandinavia and the northwestern U.S.—putting 2010 on track to surpass 2005 as the warmest year on record. Even in the higher reaches of the atmosphere—where cooling of the upper levels generally continues thanks to climate change below—June was the second warmest month since satellite record-keeping began in 1978, trailing only 1998. "Warmer than average global temperatures have become the new normal," says Jay Lawrimore, chief of climate analysis at NOAA's National Climatic Data Center, which tracks these numbers. "The global temperature has increased more than 1 degree Fahrenheit [0.7 degree C] since 1900 and the rate of warming since the late 1970s has been about three times greater than the century-scale trend."
  • All this heat comes at a time when the sun—despite a recent uptick in solar storm activity, much of it associated with sunspots, since late 2008—continues to pump out slightly less energy. This diminished solar radiation should be promoting a slight cooling but is apparently outweighed by the ongoing accumulation of atmospheric greenhouse gases, particularly carbon dioxide, as scientists have predicted for more than a century. Of course year to year variations in weather cannot be conclusively tied to climate change, which is best measured by a multiyear trend, such as the long-term trend of warming into which this year fits—2000 to 2010 is already the warmest decade since records have been kept and the 10 warmest average annual surface temperatures have all occurred in the past 15 years.
  • ...1 more annotation...
  • "Frankly, I was expecting that we'd see large temperature increases later this century with higher greenhouse gas levels and global warming," Stanford climate scientist Noah Diffenbaugh, who headed up the research, said in a prepared statement. "I did not expect to see anything this large within the next three decades."
Hunter Cutting

Nashville flood demonstrates impacts of climate change - 0 views

  • With torrential rains and record flooding hitting the Nashville area, Tennesseans are getting a first-hand glimpse of the future due to climate change. While individual storms can be driven by a number of factors, more frequent and heavy rains are one of the impacts of climate change that people are already experiencing in many areas of the United States. “While major storms are expected this time of year in the U.S. Southeast, global warming contributes to higher air and sea temperatures that in turn promote increased moisture in the atmosphere and more intense rainfall events,” said Dr. Kevin Trenberth, Head of the Climate Analysis Division at the National Center on Atmospheric Research.  “Any resulting flooding has a direct consequence on people’s well-being and livelihood.  Unless we address the root causes of climate change, we are likely to see more of these extreme storms in our future.” The National Oceanic and Atmospheric Administration (NOAA) recently reported that the southeastern United States has witnessed a 20 percent increase in heavy precipitation from 1958-2007, which is driven by climate change.
Hunter Cutting

All 10 NOAA climate indicators tracking warming - 0 views

  • The 2009 State of the Climate report released today draws on data for 10 key climate indicators that all point to the same finding: the scientific evidence that our world is warming is unmistakable. More than 300 scientists from 160 research groups in 48 countries contributed to the report, which confirms that the past decade was the warmest on record and that the Earth has been growing warmer over the last 50 years. Based on comprehensive data from multiple sources, the report defines 10 measurable planet-wide features used to gauge global temperature changes. The relative movement of each of these indicators proves consistent with a warming world. Seven indicators are rising: air temperature over land, sea-surface temperature, air temperature over oceans, sea level, ocean heat, humidity and tropospheric temperature in the “active-weather” layer of the atmosphere closest to the Earth’s surface. Three indicators are declining: Arctic sea ice, glaciers and spring snow cover in the Northern hemisphere.
  • “For the first time, and in a single compelling comparison, the analysis brings together multiple observational records from the top of the atmosphere to the depths of the ocean,” said Jane Lubchenco, Ph.D., under secretary of commerce for oceans and atmosphere and NOAA administrator. “The records come from many institutions worldwide. They use data collected from diverse sources, including satellites, weather balloons, weather stations, ships, buoys and field surveys. These independently produced lines of evidence all point to the same conclusion: our planet is warming,”
Hunter Cutting

Arctic ocean full up with carbon dioxide - 0 views

  • As climate scientists watched the Arctic's sea-ice cover shrink year after year, they thought there might be a silver lining: an ice-free Arctic Ocean could soak up large amounts of CO2 from the atmosphere, slowing down the accumulation of greenhouse gases and climate change. But research published in Science today suggests that part of the Arctic Ocean has already mopped up so much CO2 that it could have almost reached its limit1. Wei-Jun Cai, a biogeochemist at the University of Georgia in Athens and an international team sampled the amount of CO2 in the surface waters of the Canada Basin, in the western Arctic Ocean. "We found that ice-free basin areas had rather high CO2 values that approached atmospheric levels," says Cai. "It was not expected." Although the Arctic Ocean accounts for only 3% of the world's ocean surface area and is mostly covered in ice, it takes up 5-14% of all the CO2 absorbed by the planet's oceans. It tends to take in proportionately more CO2 because gases dissolve more easily in cold water. Scientists had previously thought that open water would promote the exchange of CO2 between the air and the ocean and that the increase in light reaching the water would also trigger the microscopic ocean plants called phytoplankton to transfer more CO2 from the atmosphere to the ocean through photosynthesis2. But that "prediction was based on observations of either highly productive ocean margins or ice-covered basins prior to a major ice retreat," says Cai. Very few scientists had surveyed CO2 concentrations in offshore waters.
Hunter Cutting

Hood Canal acidifying - 0 views

  • Unusually high acid readings were measured in the deep waters of southern Hood Canal, according to Richard Feeley, director of the Ocean Acidification Program at the Pacific Marine Environmental Laboratory. Increased acidity appears to be caused by increased carbon dioxide working its way from the atmosphere into the ocean, as well as the decomposition of organic matter in local waters. “Our calculations suggest that ocean acidification can account for a significant part of the pH decrease in this region,” said Feeley, whose laboratory is operated by the National Oceanic and Atmospheric Administration.
  • A research team found that ocean acidification caused by climate change accounts for 24 to 49 percent of the increased acidity in Hood Canal relative to pre-industrial times. The remainder of the pH shift occurs as a result of decomposition of organic material. Ocean effects provide the greatest contribution — 49 percent of the change — in winter when the rate of decomposition slows.
  • Increasing ocean acidity has been linked to the deaths of free-swimming oyster larvae at oyster hatcheries on the Oregon Coast, Newton said, and something similar may be happening at hatcheries on Hood Canal. Bill Dewey of Taylor Shellfish Farms, which operates an oyster hatchery on Dabob Bay, said oyster larvae production dropped by 60 percent in 2008 and 80 percent last year. It is too early to know how things will turn out this year, he said.
  • ...1 more annotation...
  • Some early evidence suggests that more acidic water in Hood Canal is brought to the surface during storms, Dewey said. Unlike the ocean hatcheries, where acidity is linked directly to oyster mortality, there may be other factors at play in Hood Canal. “We have some very good scientists working on this,” he said. Oyster hatcheries may be able to adjust their intake water or add chemicals to help the larvae survive, Dewey said, but oysters in the wild are another story. Hood Canal has always been known for its abundant natural production, but that could be changing. Worse, numerous other shelled organisms — including zooplankton at the base of the food web and the many filter feeders that clean the waters — may be affected by the increasing acidity.
Hunter Cutting

Carbon pollution now in dangerous range: National Academy of Science - 0 views

  •  
    A new authoritative study published July 16 by the National Academy of Sciences reports that the "likely" range for the level of carbon dioxide in the Atmosphere that will prompt warming of 2˚C (the generally accepted threshold for triggering dangerous climate change) is 370 ppm to 540 PPM, and that the level now stand at 390 ppm.
Hunter Cutting

Most severe 30 days of weather in Minnesota record - 0 views

  • Thursday Flood Risk (and the most severe 30 days in Minnesota history?)
  • Paul's Star Tribune Outlook for the Twin Cities and all of Minnesota
  • we just lived through an incredible 30-day period. According to the local National Weather Service Office in Chanhassen we experienced 395 severe storms between June 17 and July 17. That compares to 120 severe storms in all of 2009! So in a mere 30 days we saw more than 3 TIMES more severe weather than we did all of last year.
  • ...3 more annotations...
  • SPC issued a "moderate risk" of severe storms and tornadoes a total of 5 times, in just 30 days. To put that in perspective between 2008 and early 2010 SPC had issued 5 moderate risks. So we endured (in one month) what had previously taken over 2 years to achieve in terms of elevated weather risk.
  • Soak up today's blue sky and 80-degree highs, because the latest NAM/WRF model (probably the most accurate & reliable simulation of future weather) is printing out nearly 4" of rain for the metro area Thursday. If that verifies it would be nearly a MONTH'S worth of rain in less than 12 hours.
  • Finally, the latest from NOAA: June was the warmest month, worldwide, since accurate records were first started in 1880. It was the 4th consecutive month of record warmth around the world, the 304 month in a row where global temperatures were above the 20th century average. 2010 is still on track to be the warmest year (globally) on record, even warmer than 2005. More coincidences? Possibly, but at some point you look at all these trends, scratch your head, and wonder if maybe those climate scientists aren't right (a recent poll of published, active PhD climate scientists showed that 97% of them believe the earth's atmosphere is warming, and man has at least some role in this warming trend). That's good enough for me - should be good enough for all of us mere mortals (who don't study the earth's climate 18 hours/day). The professional (paid) deniers and their "institutes" will come up with more excuses and refutations, citing a global conspiracy among climate scientists. Don't believe them, any more than you'd believe a tobacco lobbyist denying the ill effects of smoking and the link between tobacco and cancer. The trends are apparent to anyone taking the time to really look at the science. No one heat wave, month or year proves anything, but what we have here is a steady trickle of evidence, a gradual accumulation of coincidences that can no longer be denied. Melting glaciers, thinning arctic ice, rising sea levels, an uptick in drought and 1-in-500 year floods are all symptoms. The earth's atmosphere is running a mild fever. The question: do we believe the doctors and treat the patient now, or wait for those symptoms to worsen? It's not ideology, it's not a political litmus test, it's not a "new religion." It's basic science.
Hunter Cutting

Big snow storms not inconsistent with - and may be amplified by - a warming planet - 0 views

  • there was a detailed study of “the relationships of the storm frequencies to seasonal temperature and precipitation conditions” for the years “1901–2000 using data from 1222 stations across the United States.”  The 2006 study, “Temporal and Spatial Characteristics of Snowstorms in the Contiguous United States” (Changnon, Changnon, and Karl [of National Climatic Data Center], 2006) found we are seeing more northern snow storms and that we get more snow storms in warmer years: The temporal distribution of snowstorms exhibited wide fluctuations during 1901–2000, with downward 100-yr trends in the lower Midwest, South, and West Coast. Upward trends occurred in the upper Midwest, East, and Northeast, and the national trend for 1901–2000 was upward, corresponding to trends in strong cyclonic activity…..
  • Results for the November–December period showed that most of the United States had experienced 61%– 80% of the storms in warmer-than-normal years. Assessment of the January–February temperature conditions again showed that most of the United States had 71%–80% of their snowstorms in warmer-than-normal years. In the March–April season 61%–80% of all snowstorms in the central and southern United States had occurred in warmer-than-normal years…. Thus, these comparative results reveal that a future with wetter and warmer winters, which is one outcome expected (National Assessment Synthesis Team 2001), will bring more snowstorms than in 1901–2000. Agee (1991) found that long-term warming trends in the United States were associated with increasing cyclonic activity in North America, further indicating that a warmer future climate will generate more winter storms.
  • the U.S. Global Change Research Program (USGCRP) U.S. Climate Impacts Report from 2009, which reviewed the literature and concluded: Cold-season storm tracks are shifting northward and the strongest storms are likely to become stronger and more frequent.
  • ...4 more annotations...
  • Large-scale storm systems are the dominant weather phenomenon during the cold season in the United States. Although the analysis of these storms is complicated by a relatively short length of most observational records and by the highly variable nature of strong storms, some clear patterns have emerged.112 [Kunkel et al., 2008] Storm tracks have shifted northward over the last 50 years as evidenced by a decrease in the frequency of storms in mid-latitude areas of the Northern Hemisphere, while high-latitude activity has increased. There is also evidence of an increase in the intensity of storms in both the mid- and high-latitude areas of the Northern Hemisphere, with greater confidence in the increases occurring in high latitudes.112 [Kunkel et al., 2008] The northward shift is projected to continue, and strong cold season storms are likely to become stronger and more frequent, with greater wind speeds and more extreme wave heights.68 [Gutowski et al, 2008]
  • The northward shift in storm tracks is reflected in regional changes in the frequency of snowstorms. The South and lower Midwest saw reduced snowstorm frequency during the last century. In contrast, the Northeast and upper Midwest saw increases in snowstorms, although considerable decade-to-decade variations were present in all regions, influenced, for example, by the frequency of El Niño events.112 [Kunkel et al., 2008]
  • Then we have this apparently as yet unpublished research presented by Dr James Overland of the NOAA/Pacific Marine Environmental Laboratory at the recent International Polar Year Oslo Science Conference (IPY-OSC) where he was chairing “a session on polar climate feedbacks, amplification and teleconnections, including impacts on mid-latitudes.” “Cold and snowy winters will be the rule, rather than the exception,” says Dr James Overland…. Continued rapid loss of sea ice will be an important driver of major change in the world’s climate system in the years to come…. “While the emerging impact of greenhouse gases is an important factor in the changing Arctic, what was not fully recognised until now is that a combination of an unusual warm period due to natural variability, loss of sea ice reflectivity, ocean heat storage and changing wind patterns working together has disrupted the memory and stability of the Arctic climate system, resulting in greater ice loss than earlier climate models predicted,” says Dr Overland. “The exceptional cold and snowy winter of 2009-2010 in Europe, eastern Asia and eastern North America is connected to unique physical processes in the Arctic,” he says.
  • Even though these storms occurred during warmest winter on record, I think the best way to talk about it until Overland publishes his work is the way NCAR’s Kevin Trenberth did on NPR (audio here): RENEE MONTAGNE, host:  With snow blanketing much of the country, the topic of global warming has become the butt of jokes. Climate skeptics built an igloo in Washington, D.C. during last weeks storm and dedicated it to former Vice President Al Gore, who’s become the public face of climate change. There was also a YouTube video called “12 Inches of Global Warming” that showed snowplows driving through a blizzard.For scientists who study the climate, it’s all a bit much. As NPRs Christopher Joyce reports, they’re trying to dig out. CHRISTOPHER JOYCE: Snowed-in Washington is where much of the political debate over climate change happens. So it did not go unnoticed when a Washington think-tank that advocates climate action had to postpone a climate meeting last week because of inclement weather. That kind of irony isnt lost on climate scientists. Most don’t see a contradiction between a warming world and lots of snow. Heres Kevin Trenberth, a prominent climate scientist at the National Center for Atmospheric Research in Colorado. Mr. KEVIN TRENBERTH (Scientist, National Center for Atmospheric Research): The fact that the oceans are warmer now than they were, say, 30 years ago, means there’s about, on average, 4 percent more water vapor lurking around over the oceans than there was, say, in the 1970s. JOYCE: Warmer water means more water vapor rises up into the air. And what goes up, must come down. Mr. TRENBERTH: So one of the consequences of a warming ocean near a coastline like the East Coast and Washington, D.C., for instance, is that you can get dumped on with more snow, partly as a consequence of global warming. JOYCE: And Trenberth notes that you don’t need very cold temperatures to get big snow. In fact, when the mercury drops too low, it may be too cold to snow. There’s something else fiddling with the weather this year: a strong El Nino. That’s the weather pattern that, every few years, raises itself up out of the western Pacific Ocean and blows east to the Americas. It brings heavy rains and storms to California and the South and Southeast. It also pushes high-altitude jet streams farther south, which brings colder air with them. Trenberth also says El Nino can lock in weather patterns like a meteorological highway, so that storms keep coming down the same track. True, those storms have been big ones – record breakers. But meteorologist Jeff Masters, with the Web site Weather Underground, says it’s average temperatures — not snowfall — that really measure climate change. There’s more water vapor lurking around the oceans, and whatever the proximate cause of any one snow storm, there is little doubt that global warming means the overwhelming majority of East Coast storms will be sweeping in more moisture and dumping it on the ground.
Hunter Cutting

Climate changes worst in western states - 0 views

  • In their overview of shifting climate in the region, Overpeck and Udall cite published findings of prevalent signs of change: rising temperatures, earlier snowmelt, northward-shifting winter storms, increasing precipitation intensity and flooding, record-setting drought, plummeting Colorado River reservoir storage, widespread vegetation mortality and more large wildfires. "The West, and especially the Southwest, is leading the nation in climate change – warming, drying, less late-winter snowpack and drought – as well as the impacts of this change," said Overpeck, a UA professor of geosciences and atmospheric sciences and co-director of the Institute of the Environment. In the past 10 years, temperatures in almost all areas in western North America have surpassed the 20th century average, many by more than 1 or even 2 degrees Fahrenheit. The warming has decreased late-season snowpack, which serves as a water reservoir, as well as the annual flow of the Colorado River, the researchers said.
  • Those reductions, combined with the worst drought observed since 1900, haven't helped matters; water storage in Lakes Powell and Mead, the largest southwestern water reservoirs, fell nearly 50 percent between 1999 and 2004 and has not risen significantly since.
  • In addition to water, vegetation is feeling the effects of climate change. Work by UA's David Breshears and colleagues have already showed that more than 1 million hectares of piñon pine have died in the Southwest in the last few decades from a lethal combination of record-high temperatures and uncommonly severe drought. In addition, the frequency of large wildfires has increased as snowpack has decreased.
  • ...1 more annotation...
  • While researchers are confident that the higher temperatures and resulting changes in snowpack, Colorado River flow, vegetation mortality and wildfires are human-caused, they don't know whether the drought that has plagued the West for the last 10 years – the worst since record-keeping began – is because of humans, Overpeck said.
Hunter Cutting

Record High Temperatures Far Outpace Record Lows Across U.S. - 0 views

  • Spurred by a warming climate, daily record high temperatures occurred twice as often as record lows over the last decade across the continental United States
  • "Climate change is making itself felt in terms of day-to-day weather in the United States," says Gerald Meehl, the lead author and a senior scientist at the National Center for Atmospheric Research (NCAR). "The ways these records are being broken show how our climate is already shifting."
  • If temperatures were not warming, the number of record daily highs and lows being set each year would be approximately even. Instead, for the period from January 1, 2000, to September 30, 2009, the continental United States set 291,237 record highs and 142,420 record lows, as the country experienced unusually mild winter weather and intense summer heat waves. A record daily high means that temperatures were warmer on a given day than on that same date throughout a weather station's history.
  • ...2 more annotations...
  • The study also found that the two-to-one ratio across the country as a whole could be attributed more to a comparatively small number of record lows than to a large number of record highs. This indicates that much of the nation's warming is occurring at night, when temperatures are dipping less often to record lows. This finding is consistent with years of climate model research showing that higher overnight lows should be expected with climate change.
  • "If the climate weren't changing, you would expect the number of temperature records to diminish significantly over time," says Claudia Tebaldi, a statistician with Climate Central who is one of the paper's co-authors. "As you measure the high and low daily temperatures each year, it normally becomes more difficult to break a record after a number of years. But as the average temperatures continue to rise this century, we will keep setting more record highs."
Hunter Cutting

Arctic sea ice at record low for June - 0 views

  • Average June ice extent was the lowest in the satellite data record, from 1979 to 2010. Arctic air temperatures were higher than normal, and Arctic sea ice continued to decline at a fast pace. June saw the return of the Arctic dipole anomaly, an atmospheric pressure pattern that contributed to the record sea ice loss in 2007.
  • At the end of May 2010, daily ice extent fell below the previous record low for May, recorded in 2006, and during June continued to track at record low levels
  • The linear rate of monthly decline for June over the 1979 to 2010 period is now 3.5% per decade. This year’s daily June rate of decline was the fastest in the satellite record; the previous record for the fastest rate of June decline was set in 1999
  • ...1 more annotation...
  • Ron Kwok of the Jet Propulsion Laboratory (JPL) reports that Nares Strait, the narrow passageway between northwest Greenland and Ellesmere Island is clear of the ice “arch" that usually plugs southward transport of the old, thick ice in the Lincoln Sea. Typically the ice arch forms in winter and breaks up in early July. This year the arch formed around March 15th and lasted only 56 days, breaking up in May. In 2007 the ice arch did not form at all, allowing twice as much export through Nares Strait than the annual mean. Although the export of sea ice out of the Arctic Ocean through Nares Strait is very small in comparison to the export through Fram Strait, the Lincoln Sea contains some of the Arctic’s thickest ice.
Hunter Cutting

Global C02 levels approaching tipping point for Arctic - 0 views

  • "Our findings indicate that CO2 levels of approximately 400 parts per million are sufficient to produce mean annual temperatures in the High Arctic of approximately 0 degrees Celsius (32 degrees F)," author Ashley Ballantyne said in a release. "As temperatures approach 0 degrees Celsius, it becomes exceedingly difficult to maintain permanent sea and glacial ice in the Arctic. Thus current levels of CO2 in the atmosphere of approximately 390 parts per million may be approaching a tipping point for irreversible ice-free conditions in the Arctic."
  •  
    [Ed. note -The impact of global warming on the Arctic sea ice is watched closely not only because the status of the ice serves as an early warning system, but also because the huge polar ice cap serves as an air conditioner for the planet (via the albedo effect). If the Arctic tips and the sea ices disappears, global warming will accelerate.]
Hunter Cutting

Above Normal Spring Temperatures in U.S. Continue Long-Term Upward Trend; Record Warmth... - 0 views

  • The National Oceanic and Atmospheric Administration (NOAA)released today (8 June 2010) temperature and precipitation data for May and Spring in the U.S.  Nationwide, above-normal spring temperatures continued a long-term upward trend.  It was the warmest spring on record for eight northeastern states; and one of the top ten warmest springs for another ten states.
Hunter Cutting

World on Track for Warmest Year on Record - 0 views

  • The current year may become the warmest on record, according to a National Oceanic and Atmospheric Administration scientist. Temperature trends across the U.S. and around the world have been among the warmest on record, said David Easterling, a climatologist with NOAA’s National Climatic Data Center in Asheville, North Carolina.
  • The combined land and ocean temperatures around the world were 1.22 degrees warmer than the 20th-century average, according to NOAA records. Since 1975, global temperatures have been rising and since 1960 the number of heat waves has been increasing, Easterling said
  • “The current spate of heat waves could be a harbinger of things to come.”
  • ...2 more annotations...
  • Much of the U.S. Northeast has been gripped by a heat wave that broke temperature records in New York, Washington and Baltimore and brought 100 degrees or more to Newark four days in a row.
  • Energy use has risen and utilities have asked customers to curb their use to conserve power
Hunter Cutting

Ocean Ecosystems Transforming Due to Climate Change - 0 views

  • Global climate change is fundamentally disrupting marine ecosystems, especially in the polar oceans, according to two new reviews of scientific research released Thursday in the journal Science.
  • Changes in temperature, ocean acidity and volume are affecting species from phytoplankton — the microscopic marine plants at base of the food chain — to polar bears, which may lose 68 percent of their summer habitat by 2100. "Climate change is affecting an enormously wide range of physical and biological aspects of the ocean," said John Bruno, a University of North Carolina marine ecologist and co-author of one of the reviews. "Once you start tweaking temperature, everything changes." Photosynthesis by phytoplankton is down six percent since the 1980s, and the organisms themselves are getting smaller thanks to warmer temperatures, the review noted.
  • Less plankton means less food for fish, which in turn means less seafood for human consumption. Phytoplankton also absorb carbon dioxide from the air and sequester it at the seafloor when they die and sink to the bottom of the ocean. Fewer phytoplankton could mean more human carbon dioxide emissions stay in the atmosphere, Bruno said, further exacerbating the climate change problem.
  • ...2 more annotations...
  • The "canary in the coalmine" for all of these shifts is the polar oceans, said Oscar Schofield, an oceanographer at Rutgers University in Newark, New Jersey and a co-author of the second review, which focuses on changes at the West Antarctic Peninsula. There, the authors found, temperatures have increased by 6 degrees Celsius in the past 50 years, more than five times the average change worldwide. Phytoplankton blooms are down 12 percent overall. Krill populations — important food for whales, penguins, fish and other large animals — are plummeting, with jellyfish-like organisms called salps, which don't make as good a meal, taking their place.
  • Above the surface, the polar Adélie penguin population has gone from tens of thousands of breeding pairs to just a few thousand, Schofield said. Temperate species of penguin like the Chinstrap and Gintoo are moving into the Adélie’s old turf. Particularly shocking, Schofield said, is how rapidly these changes are occurring. "It's not like it's happening over hundreds of years," he said. "It's happening over decades."
Hunter Cutting

Flooding now regular event for Mulegé river in Baja - 0 views

  • A picturesque Baja town has been hammered repeatedly by the escalating tempo of flooding from tropical storms.
  • Why the frequency of floods now after so many quiet years? “I think it’s global warming,” said Christopher.
  • “Before we got here in 1982, there had been two floods on record,” Christopher, a retired Californian and Rotary Club member, told me. “The floods of 1914 and 1955. Then since 2006, we had three floods — almost one every year! I’m starting to get tired of rebuilding the roof and everything else.”
  • ...1 more annotation...
  • There is agreement on one issue: excess greenhouse gases in the atmosphere will increase the intensity of storms (in general) and especially rainfall, since warmer conditions allow more water vapor to be sucked from the air. The higher risk of flooding is especially problematic for coastal areas because of storm surge. Researchers analyzing streamflows in large basins and GHG trends conclude that so-called 100-year floods likely will become more frequent.
1 - 20 of 26 Next ›
Showing 20 items per page