tagged w/ positive feedback loop
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Let’s call it the polar express.
The multi-year ice floes that once dominated the Arctic Ocean have been shrinking fast over the past decade, replaced by pans that form anew each winter and melt away each spring. The increase in the extent of this seasonal ice has the potential to dramatically accelerate the warming of the planet’s far northern sea, according to a new four-year study published this week in Geophysical Research Letters.
It’s all hinges on how much sunshine gets absorbed and how much is bounced back into space over the course of a season, a physical process that scientists call albedo.
“My connection is really to answer a simple question — ‘Where does all the sunlight go?’” is how lead researcher Donald Perovich explained it in a You Tube video about the research near Barrow. “Or, to put it more scientifically, how is solar radiation partitioned among reflection, absorption and the ice in transmission to the ocean?”
The dazzling white and rugged surface of old, thick ice has the potential to reflect gobs of sunlight all summer. But the more fragile and flatter seasonal floes behave differently as the weeks pass — morphing from melting snow to standing ponds to the roiling green-gray of actual open water. As the ocean surface dominated by seasonal ice becomes less reflective, it absorbs more and more energy.
Self-fulfilling process
Spread the result over thousands of square miles season after season, and the Arctic Ocean will grow warmer at a much faster rate, boosting some forms of sea life while advancing the destruction of the seasonal ice cap, according to the findings in “Albedo evolution of seasonal Arctic sea ice.” In a sense, it’s becoming a self-fulfilling process, where the meltback of sea ice leads to an increasingly warmer upper ocean that leads to even greater ice loss in coming seasons.
“Once surface ice melt begins, seasonal ice albedos are consistently less than albedos for multi-year ice, resulting in more solar heat absorbed in the ice and transmitted to the ocean," wrote Perovich and co-author Christopher Polashenski, both with the U.S. Army’s Cold Regions Research and Engineering Laboratory in New Hampshire. This "shift from multi-year to seasonal ice cover has significant implications for the heat and mass budget of the ice and for primary productivity in the upper ocean.”
Tracking the dynamics of Arctic ice has never been more urgent. The extent and volume of the polar ocean’s ice cap has been shrinking fast over the past decade, climaxing each September with minimums at record and near record levels. (This spring, the extent of Arctic ice was greater than any late winter since the early 2000s, but still far below the long-term average for the time of year. See the May update from the National Snow & Ice Data Center.) Some climate models predict the Arctic will lose most of its multi-year ice by the end of the century if trends don’t change, with most of the ocean becoming ice-free by the end of every summer.
Theats to polar bears, walruses
An extensive polar ice cap has long played an essential role in stabilizing the world’s climate. It also provides essential habitat for healthy populations of polar bears, walruses and seals, and its disappearance during summer may threaten their survival. There are expensive indirect consequences too. The summer loss of ice has been creating fetches of hundreds of miles along the Chukchi and Beaufort sea coasts that now often expose Alaskan villages to catastrophic storms and erosion when fall weather starts bearing down.
More at the linkLet’s call it the polar express.
The multi-year ice floes that once dominated... more
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Permafrost zones extend over 50% of Canada's land area. Warming or thawing of permafrost due to climate change could significantly impact existing infrastructure and future development in Canada's north.
Researchers Jennifer Throop and Antoni Lewkowicz at the University of Ottawa, along with Sharon Smith with the Geological Survey of Canada, have published a new study, part of an upcoming special issue of the Canadian Journal of Earth Sciences (CJES), that provides one of the first summaries of climate and ground temperature relations across northern Canada.
Dr. Christopher Burn, Editor of the CJES special issue on fundamental and applied research on permafrost in Canada, says the study by Throop, Lewkowicz, and Smith is unusual because it presents data on permafrost throughout Canada's three northern territories.
Most previous reports have concentrated on restricted regions within the North, but this paper presents conditions at the continental scale. This summary shows the factors that govern the response of permafrost to climate change, and indicates how the emphasis on snow conditions, soil moisture conditions, and surface peat and moss varies across the North.
"This important research gives strategic assistance in projecting how permafrost may change with the climate, as it pinpoints important characteristics, and demonstrates how these vary from place to place," says Burn.
"The response of permafrost to climate change is a critical factor Canadians must anticipate if our northern infrastructure is to be adapted to thawing ground."Permafrost zones extend over 50% of Canada's land area. Warming or thawing of... more
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The disappearance of Arctic sea ice has crossed a "tipping point" that could soon make ice-free summers a regular feature across most of the Arctic Ocean, says a British climate scientist who is setting up an early warning system for dangerous climate tipping points.
Tim Lenton at the University of Exeter has carried out a day-by-day assessment of Arctic ice-cover data collected since satellite observation began in 1979. He presented his hotly anticipated findings for the first time at the Planet Under Pressure conference in London on Monday.
Up until 2007, sea ice systematically fluctuated between extensive cover in winter and lower cover in summer. But since then, says Lenton, the difference between winter and summer ice cover has been a million square kilometres greater than it was before, as a result of unprecedented summer melting. These observations are in contrast to what models predict should have happened.
Permanent alteration
Despite fears of runaway sea-ice loss after summer cover hit an all-time low in 2007 – opening the Northwest Passage for the first time in living memory – modelling studies based on our best understanding of ice dynamics indicated the ice cover should fully recover each winter. "They suggest that even if the ice declined a large amount in one year, it should bounce back," says Walt Meier of the US National Snow and Ice Data Center in Boulder, Colorado.
Instead, Lenton's research shows a permanent alteration. According to data from the past five years, the Arctic sea ice has not recovered from the 2007 extreme low. "The system has passed a tipping point," he says.
What caused the change is still unclear. Lenton speculates that the exceptional low in 2007 (pictured, above right) might have allowed the ocean to absorb so much heat that a lot of the thicker multiyear ice, which used to persist through the summer, was melted. Alternatively, the loss of ice may have changed air circulation patterns above the Arctic in ways that have similarly "locked in" the change.
More at the linkThe disappearance of Arctic sea ice has crossed a "tipping point" that could... more
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Thirty per cent of the Earth’s surface is affected by fire. Fire destroys forests and vegetation which are our sources of food – it is both a driver and an indicator of climate change.
When biomass is burned, copious amounts of gases and particulate matter are released, billowing smoke plumes fill the sky, and entire ecosystems can change in seconds.
“We’ve seen very saddening situations of fires, particularly in Africa, West America and the Amazon. Fires have been increasing, and have been responsible for thousands of citizens to be relocated. Enormous amounts of money have been spent on destroyed homes and property,” says Jimmy Adegoke, a climate scientist at the Council of Scientific and Industrial Research (CSIR) in South Africa. “Texas in the United States has experienced its record hottest summer this year with record heat waves, droughts and fires.”
The rate of biomass burning is expected to increase in coming years, because climate change causes hotter and drier conditions. Additionally built-up material from repeated fire suppression provides ideal conditions for fires to burn strongly when they eventually break out.
These fires can be seen from space. Using infrared images, satellites can view the hotspots and origin of fires through dark clouds of smoke which can’t be seen with the naked eye. In 2000, NASA launched two minibus-sized satellites, Terra and Aqua, with instruments called MODIS attached to them to scan the globe daily, looking specifically for fire ‘scars’.
“In July I flew over the burning Amazon area in a 2000 kilometre smoke ball. The sun was dim and red and the sky was grey and black. Down here we think it’s bad, but if you see the fires from space, you see how bad it really is and how big the affected areas are,” says Piers Sellers, research scientist for National Aeronautics and Space Administration (NASA).
“Fires change the characteristics of the ‘clouded south’. Fires affect the interaction between clouds, the sun and the Earth’s surface.” Clouds play an important role in the climate system – fire emissions change the colour and optical characteristics of clouds. Instead of acting as reflectors, clouds now have much more absorption qualities.
“Solar radiation is either retained, reflected by clouds or enters the atmosphere. Mostly it warms the Earth’s surface, which can result in fires.” A high frequency of fire outbreaks causes dark burnt areas which increases the absorption power of heat of the Earth’s surface.
“We are expecting a bigger release of carbon in the atmosphere due to fires,” Adegoke says. Plants grow and use CO2 from the atmosphere to build and maintain biomass and remove CO2.
Burning coal, oil and natural gas transforms carbon from fossil pools created millions of years ago in the Earth’s atmosphere, and affects the climate and ecosystems.
NASA satellites’ tracking of smoke plumes have clearly indicated that fires have a global effect, because their emissions get carried by wind currents.
“The major sources of fires are localised at different times of the year, but the impacts are global.” CO2 has gone up and down, but is ultimately increasing. This affects the Earth’s sustainability potential – the ability of ecosystems to support productivity, especially in north and mid-Africa.
Fires lead to human suffering, poverty, frustration and wars on a regional and global scale. “These effects are aggravated by societies’ lack of interest in global change issues, non-participation in mitigation effort and more biomass burning for survival.”
According to Adegeko, increased fire frequency is directly related to water and rainfall patterns. His current research looks closely at how this impacts on the seven African countries that rely on Lake Chad, which is drying up at an alarming rate. “40 years ago, it was the biggest lake in Africa, but now it is less than 20% what it used to be. This affects the livelihoods of 40 million African people.”
Satellites help scientists track from space where fires are, how intense they are, and where emissions are going in the atmosphere. According to NASA waves of fires occur each year in Africa, starting in the north and moving down to the south. “Documenting fire patterns are important, because they make up a big part of the carbon budget,” Sellers says.
“Beyond observing, the satellites provide information used to create early warning systems,” Adegoke says. Each year Eskom, which produces 95% of South Africa’s electricity and 70% of Africa’s electricity, experiences a substantial amount of down time on its transmission lines due to wildfires. “South Africa is a water scarce country and fire poses a real threat to their people and their biodiversity. South Africa is the third most naturally diverse country in the world.”
South Africa’s geographical position gives them the advantage of being able to track satellites with an advanced capability, which has led to the development of the successful Advanced Fire Information System (AFIS).
AFIS uses SMS alerts to disseminate critical information to fire brigades, farmers, energy providers and fire managers.
“Not all fires are bad, some have a useful productive ecological function, but more needs to be done to manage human-induced fires,” Adegoke says. Sub-saharan Africa uses an agricultural method called ‘slash and burn’, an agricultural practice aimed at preparing land to grow crops quickly and efficiently in areas that were once forested. “A lot of unnecessary burning is done in this way and it has unintentional consequences.”
More at the linkThirty per cent of the Earth’s surface is affected by fire. Fire destroys... more
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Global warming has often been discussed with regard to its effects for life on land: increased temperatures and heat waves, increased weather extremes, less but more intense rainfall, drought and forest fires.
Water, however, remains less considered. Even discussions of floods or rising sea levels, which focus on water, study mainly their consequences for land inhabitants.
Yet oceans, it is well known, cover three quarters of the earth's surface. And oceans have absorbed about a quarter of all carbon dioxide (CO2) emissions, one of four main greenhouse gases causing global warming. This absorption of CO2 is integrally related to the three major factors impacting the oceans: global warming, ocean acidification and decreasing amounts of oxygen. As a result, the current situation of the oceans is dire. And its impact will be severe not only for marine life but also for all life -- plant, animal and human -- on land.
Ocean Acidification
Carbon dioxide (CO2) exists naturally in the air. But through the use of fossil fuels, in particular coal and oil, the amount of CO2 in the air has increased exponentially since the Industrial Revolution began.
As the oceans absorb carbon from the air, their chemistry changes. This process is known as ocean acidification, and it has brutal consequences for marine and land life.
Oceanographers estimate that before the use of fossil fuels, the ocean's PH balance, which measures its acidity, had been relatively stable for the past 20 million years. During the last great extinction of marine life, which occurred 55 million years ago, 50 percent of some groups of deep sea animals were wiped out.
But the current levels of carbon being absorbed by the oceans is far higher than the levels being absorbed then.
A United Nations Environment Program (UNEP) report released in 2010 on the "Environmental Consquences of Ocean Acidification" and based on studies conducted over the past two decades off the coast of Hawai'i has confirmed that the increased CO2 concentration levels in the ocean mirror the increased CO2 levels in the atmosphere.
Ocean Acidification and Phytoplankton
Already the increased levels of ocean acidification have led to a loss of phytoplankton and of coral reefs. And losses of phytoplankton and of coral reefs have a ripple effect.
First, much marine life relies on them for nourishment. Flounder, haddock, pollock, salmon and shrimp all eat phytoplankton. Humans eat many of these fish. Krill eat phytoplankton and whales eat krill. So a decrease in one threatens the liveilhood of the other.
Second, phytoplankton also absorbs carbon dioxide. Phytoplankton floats along the ocean's surface absorbing CO2 as land plants do in photosynthesis. As the CO2 is absorbed, the plant dies and sinks to the ocean floor, releasing CO2 along the way. Cold water can hold higher levels of CO2 than warmer water, so most of the CO2 released, which turns water acidic, is to be found along the ocean floor. But this acidic water does not stay at the ocean's floor. During an upswell, it rises to the surface and even the shore. Its acidity is deadly for the shells of marine life, such as shrimps, clams and oysters.
If the smallest part of the food chain is affected by ocean acidification, it ripples all the way up the food chain, making the largest part of the food chain vulnerable.
"Since the time before the industrial revolution," says the National Resource Defense Council's Lisa Suatoni, "ocean acidity has increased 30 percent."
And the bad news does not end there: According to oceanographers, the water rising from the ocean's depths holds CO2 that has accumulated over the past decades. Thus, in coming years, the increased levels of CO2 absorbed by the oceans will re-emerge as increased ocean acidification reaching the shores. Higher levels of cean acidification have already led to tremendous problems for the oyster industry. In the summer of 2007 oyster harvests began to plummet in the Pacific Northwest. The situation was extreme. The oyster hatcheries were keen to find the culprit, which turned out to be ocean acidification.
More at the linkGlobal warming has often been discussed with regard to its effects for life on land:... more
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Ice is the white flag being waved by our planet, under fire from the atmospheric attack being mounted by humanity. From the frosted plains of the Arctic ice pack to the cool blue caverns of the mountain glaciers, the dripping away of frozen water is the most crystal clear of all the Earth's warning signals.
It relies on neither the painstaking compiling of temperature records back through history nor the devilish complexity of predicting the future with supercomputers. Ice on Earth is simply and unambiguously disappearing. Last week saw the annual summer minimum of the Arctic ice cap, which has now shrunk to the lowest level satellites have ever recorded. The ice at the roof of the human world is faring little better: mountain glaciers are diminishing at accelerating and historic rates.
The lower glaciers are doomed. Kilimanjaro may be bare within a decade, with the Pyrenees set to be ice-free by mid-century and three-quarters of the glaciers in the Alps gone by the same date. As you climb higher, and temperatures drop, global warming will take longer to erode the ice into extinction. But at the "third pole", in the Himalayas, the ice is melting as evidenced by dozens of swelling milky blue lakes that threaten to burst down on to villages when their ice dams melt.
The threat posed is far greater than even this terrifying prospect: a quarter of the world's people rely on Himalayan meltwater, which helps feed the great rivers that plunge down into Asia. The Yellow, Yangtze, Mekong, Brahmaputra, Ganges and Indus nourish billions and will eventually lose their spring surges.
Melting ice is the cause of another of the greatest long-term threats posed by climate change: rising sea level. The deep freezes of Greenland and west Antarctica store enough water to raise the oceans by 20 feet. That would flood many of the world's greatest cities from New York to Shanghai, but remains for now a distant prospect.
More at the linkIce is the white flag being waved by our planet, under fire from the atmospheric... more
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Time to get louder at government about this. Time to win this conversation with truth. CO2 traps heat. One of the main points of this, plus some others I divulge. ;l). Thanks Current for this venue for us to tell it like it is.
This video is dedicated to the indigenous peoples of our world and those experiencing the brunt of the effects of climate change/biodistress. May we find it within us to do what is right for all.Time to get louder at government about this. Time to win this conversation with truth.... more
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This is from the:
Snippet from link:
OBuoy Project, where real-time telemetry is used to bring both data and video from a buoy (UBuoy 2) moored in the Barents Sea north of Alaska to anyone with a web connection. Scientists have even spliced images from the buoy into a spectacular movie for all to see.
Prospects for continued documentation of the sea ice melt around the buoy seem to have dimmed somewhat lately, as video transmission has ceased and the temperature of its battery has spiked (suggesting that the buoy may have been swamped by ice).
H/T to Neven's Sea Ice blog contributor R. Gates, who alerted folks there as to the UBuoy Program and to another contributor at Neven's, Rob Dekker, who found the video and the evidence of the buoy's perhaps premature end.This is from the:
Snippet from link:
OBuoy Project, where real-time telemetry is... more
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On a small, floating piece of ice in the Beaufort Sea, several hundred miles north of Alaska, a group of scientists are documenting what some dub an "Arctic meltdown."
According to climate scientists, the warming of the region is shrinking the polar ice cap at an alarming rate, reducing the permafrost layer and wreaking havoc on polar bears, arctic foxes and other indigenous wildlife in the region.
What is bad for the animals, though, has been good for commerce.
The recession of the sea ice and the reduction in permafrost -- combined with advances in technology -- have allowed access to oil, mineral and natural gas deposits that were previously trapped in the ice.
The abundance of these valuable resources and the opportunity to exploit them has created a gold rush-like scramble in the high north, with fierce competition to determine which countries have the right to access the riches of the Arctic.
This competition has brought in its wake a host of naval and military activities that the Arctic hasn't seen since the end of the Cold War.
Now, one of the coldest places on Earth is heating up as nuclear submarines, Aegis-class frigates, strategic bombers and a new generation of icebreakers are resuming operations there.
Just how much oil and natural gas is under the Arctic ice?
The Arctic is home to approximately 90 billion barrels of undiscovered but recoverable oil, according to a 2008 study by the U.S. Geological Survey. And preliminary estimates are that one-third of the world's natural gas may be harbored in the Arctic ice.
But that's not all that's up for grabs. The Arctic also contains rich mineral deposits. Canada, which was not historically a diamond-producing nation, is now the third-largest diamond producer in the world.
If the global warming trend continues as many scientists project it to, it is likely that more and more resources will be discovered as the ice melts further.
Who are the countries competing for resources?
The United States, Canada, Russia, Norway, Denmark, Iceland, Sweden and Finland all stake a claim to a portion of the Arctic. These countries make up the Arctic Council, a diplomatic forum designed to mediate disputes on Arctic issues
Lawson Brigham, a professor at the University of Alaska Fairbanks and an Arctic expert, says "cooperation in the Arctic has never been higher."
But like the oil trapped on the Arctic sea floor, much of the activity of the Arctic Council is happening below the surface.
In secret diplomatic cables published by WikiLeaks, Danish Foreign Minister Per Stieg Moeller was quoted as saying to the United States, "If you stay out, the rest of us will have more to carve up the Arctic."
At the root of Moeller's statement is a dispute over control of territories that is pitting friend against foe and against friend. Canada and the U.S., strategic allies in NATO and Afghanistan, are in a diplomatic dispute over the Northwest Passage. Canada and Russia have recently signed development agreements together.
In the same way a compass goes awry approaching the North Pole, traditional strategic alliances are impacted at the top of the world.
http://www.cnn.com/2011/WORLD/americas/07/15/larsen.arctic.ice.wars/index.html
More at the linkOn a small, floating piece of ice in the Beaufort Sea, several hundred miles north of... more
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We’re at a record low Arctic sea ice extent and volume:
The area of the Arctic ocean at least 15% covered in ice is … lower than the previous record low set in 2007 – according to satellite monitoring by the US National Snow and Ice Data Centre (NSIDC) in Boulder, Colorado. In addition, new data from the University of Washington Polar Science Centre, shows that the thickness of Arctic ice this year is also the lowest on record.
In the past 10 days, the Arctic ocean has been losing as much as 150,000 square kilometres of sea a day, said Mark Serreze, director of the NSIDC.
“The extent [of the ice cover] is going down, but it is also thinning. So a weather pattern that formerly would melt some ice, now gets rid of much more. There will be ups and downs, but we are on track to see an ice-free summer by 2030. It is an overall downward spiral.“
The trend is painfully obvious to all who aren’t blinded by ideology. Indeed, many, including me, believe we’ll see virtually ice-free summers within a decade.
What do the experts — and deniers — predict for the September sea ice extent minimum? The Study of Environmental Arctic Change (SEARCH) has released its second Sea Ice Outlook report for July. Just about all the cryo-scientists think the Arctic will easily beat last year’s minimum:
More at the linkWe’re at a record low Arctic sea ice extent and volume:
The area of the... more
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Continuing a pattern of heavy regional precipitation, torrential rains in late June 2011 forced more than 500,000 residents to evacuate in China’s central and eastern provinces. China Daily reported that millions of people were adversely affected in the provinces of Zhejiang, Jiangsu, Anhui, Jiangxi, Hubei, Hunan, and Guangdong. Flood waters submerged homes, crops, and roads, causing an estimated $772 million in damage in Zhejiang alone.
This image shows estimated rainfall amounts from June 13 to 19, 2011. The lowest rainfall amounts (less than 75 millimeters, or 3 inches) appear in pale green, and the heaviest amounts (more than 450 millimeters, or 18 inches) appear in dark blue. The heaviest rainfall occurs southwest of Shanghai.
A China Daily report from June 18 described the rains in parts of Zhejiang Province as unprecedented. High waters broke 100-meter (300-foot) holes in levees, inundating nearby villages. Some homes were buried in 3 meters (10 feet) of water. Farmers who managed to survive the floods wondered how they would survive the losses of their homes and crops.
On June 21, Agence France-Presse reported that another storm was nearing China’s southern coast, and was likely to bring strong winds and heavy rains to the provinces of Guangdong and Fujian over the next two days. Meanwhile, China Daily reported, risk of overflow prompted authorities at Xin’anjiang Reservoir in Zhejiang to open three of its nine floodgates.
The Washington Post has provided a photo gallery of the floods.
This image is based on data from the Multisatellite Precipitation Analysis produced at Goddard Space Flight Center, which estimates rainfall by combining measurements from many satellites and calibrating them using rainfall measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite.
References
Agence France-Presse. (2011, June 21). China braces for tropical storm amid floods. Accessed June 21, 2011.
China Daily. (2011, June 18). When the levees broke. Accessed June 20, 2011.
China Daily. (2011, June 20). Millions hit by flood havoc. Accessed June 20, 2011.
China Daily. (2011, June 21). Swelling reservoir lets flood water go. Accessed June 21, 2011.
Washington Post. (2011, June 21). Floods hit China. Accessed June 21, 2011.
NASA Earth Observatory image by Jesse Allen, using near-real-time data provided courtesy of TRMM Science Data and Information System at Goddard Space Flight Center. Caption by Michon Scott.
More at the link.Continuing a pattern of heavy regional precipitation, torrential rains in late June... more
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Wildfires are becoming more frequent and intense, lasting on average 78 days longer than they did just two decades ago. Northern Arizona University Biology Professor Bruce Hungate tells host Bruce Gellerman about research that shows a relationship between fire and the release of nitrous oxide, a potent greenhouse gas.
Transcript
GELLERMAN: From the Jennifer and Ted Stanley Studios in Somerville Mass, this is Living on Earth. I'm Bruce Gellerman. Nitrous Oxide is commonly known as laughing gas, but there’s nothing funny about its effects on climate change.
Biologist Bruce Hungate accidentally discovered that during wild fires, huge amounts of nitrous oxide in the soil are released into the atmosphere. It all has to do with microscopic bugs in the soil that give off laughing gas. Bruce Hungate is a professor at Northern Arizona University.
HUNGATE: Bacteria called denitrifiers use nitrate in respiration just like humans use oxygen, and in the process, they produce nitrous oxide. Fires promote conditions in the soil that favor production of nitrous oxide by these soil microorganisms. They’re microscopic, but their impacts are global by producing this greenhouse gas. And in fact, most of the nitrous oxide in the atmosphere comes from these tiny creatures.
GELLERMAN: So how potent is nitrous oxide as a greenhouse gas, compared to, say, carbon dioxide?
HUNGATE: So on a molecule-per-molecule basis, nitrous oxide is three hundred times more potent than carbon dioxide. That’s a very potent greenhouse gas.
GELLERMAN: So you studied grasslands, right?
HUNGATE: Right.
GELLERMAN: Would I find nitrous oxide and these little bugs that produce it in forests?
HUNGATE: Denitrifiers are everywhere. They’re in soils all around the world. And they produce nitrous oxide from these soils all around the world. And there actually have been a lot of experiments looking at the impacts of fire on nitrous oxide production from forests as well, it turns out, especially in the tropics - and often there what you see is after a fire, you get more nitrous oxide emitted from soil.
Bruce Hungate is a professor of Biology at Northern Arizona University. (Northern Arizona University.
GELLERMAN: And we didn’t know about this forest-fire and nitrous oxide relationship before?
HUNGATE: What we did know is that, in general, after fire, nitrous oxide emissions often go up. So we knew that before. What we didn’t know is how fires interact with these other components of the changing environment and in our experiment that was the real surprise.
GELLERMAN: You were running a series of experiments and you had a bunch of test plots, as I understand it, and that’s where you made your discovery.
HUNGATE: That’s right. We started this experiment back in 1998 in a grassland in California where we actually changed the physical environment around test plots to try to simulate the environment of the future. We focused on four on-going global environmental changes. More CO2 in the atmosphere, so some plots have tubes that release extra CO2 into the atmosphere around the growing plants, and also warming, we have infrared heat lamps over some plots to make them warmer. Extra nitrogen deposition - some plots get an extra dose of nitrogen simulating higher industrial activity and its effect on the atmosphere in the future. And also rainfall, some plots have sprinklers that simulate more rain. So we had each of these changes by itself, and then in every possible combination with the other global changes - it was really complex.
And then a downed power line caused a fire that burned part of it. At first we were really worried about damage to the experiment, but it turned into an opportunity. The fire burned only part of it, so we still had controls to quantify the impact of the fire along with the background of all these global environmental changes. So instead of losing the experiment, we got an even more complex experiment - very complex, but also interesting and exciting, with these new results.
GELLERMAN: So this accidental fire leads to this surprising finding that you can have accelerated global warming due to the nitrous oxide in the soil being released, essentially.
HUNGATE: Yeah, that’s exactly right, it was a surprising result. When we looked at each of these things by itself, we wouldn’t have been able to predict the result we got.
GELLERMAN: So you get this intense burst of nitrous oxide - so it’s not long lasting? Or…
HUNGATE: Well, actually it is. It was a delayed reaction. The pulse of nitrous oxide after fire lasted about three years. And that was another surprising finding, because past work on fires and nitrous oxide emissions haven’t shown quite as long lasting an effect. We think that might have to do with a combination of the global environmental changes along with the fire that really promoted nitrous oxide production.
GELLERMAN: So, Professor, let me play out the scenarios. So if you have a wildfire it releases this nitrous oxide into the atmosphere, it affects climate change dramatically, it gets warmer and causes the conditions for more wildfires - you’ve got a feedback loop here.
HUNGATE: That’s exactly right. It’s where climate change leads to more fires, which in turn lead to more climate change. And it’s not just nitrous oxide, these fires also produce carbon dioxide and methane, so they’re important sources of greenhouse gasses.
More at the link.Wildfires are becoming more frequent and intense, lasting on average 78 days longer... more
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Last month, 350.org founder Bill McKibben published a must-read op-ed about the failure of the media and others to connect any dots between recent extreme weather events and climate change. Stephen Thomson of Plomomedia has combined McKibben’s words with striking images.
Underscoring McKibben’s point is an uber-lame New York Times story today, “As Arizona Fire Rages, Officials Seek Its Cause,” which, you guessed it, is dot free. Meteorologist Dr. Jeff Masters wrote Friday, “The return of critical fire conditions this weekend means that the Wallow fire will likely become Arizona’s largest wildfire in history.”
Before taking on the NYT piece, let’s look at the video:
McKibben’s piece is a nice work of rhetoric. After April saw records set for most tornadoes in a month and in 24 hours, I examined the climate-tornado link in great detail here, looking at the data, the literature, and expert analysis. That piece concluded:
1.When discussing extreme weather and climate, tornadoes should not be conflated with the other extreme weather events for which the connection is considerably more straightforward and better documented, including deluges, droughts, and heat waves.
2.Just because the tornado-warming link is more tenuous doesn’t mean that the subject of global warming should be avoided entirely when talking about tornadoes.
The NY Times has been doing some very good science reporting recently (see NY Times Bombshell: “The latest scientific research suggests” climate change is “helping to destabilize the food system”). But their overall reporting team is not connecting the dots (see, for instance, my May piece “New York Times blows the Dust Bowl story“).
The NYT had promised two years ago to do more coherent reporting, as the Columbia Journalism Review noted at the time:
Environmental S.W.A.T. Team
On Thursday, The New York Times will launch a new, crack environmental reporting unit that will pull in eight specialized reporters from the Science, National, Metro, Foreign, and Business desks in a bid for richer, more prominent coverage.
Not.
The more prominent coverage simply never happened, as I detailed in the second half of my January piece, Silence of the Lambs: Media herd’s coverage of climate change “fell off the map” in 2010, which shows that in all of 2010 none of “the largest lead headlines” in the paper dealt with climate. As professor Robert Brulle, an expert on environmental communications, wrote me at the time:
Apparently, the editorial board of the NY Times has yet to fully grasp the importance of global climate change to our collective survival. As the science becomes stronger and more dire, the editors of the NY Times bury their head deeper into the sand.
Today’s Arizona story is a case in point. Now I don’t necessarily think that every single story written on the record Arizona wildfires must focus on or even mention climate change. But the NYT story is quite specifically on the “cause” of the fires. Worse, the newspaper has no difficulty repeating dubious right-wing myths as to the cause of the fires
Many wildfires are caused by humans — and investigators say this one may have been started by two unattended campfires — distinguishing them from hurricanes, tornadoes and earthquakes….
Residents heaped plenty of blame on Mother Nature as harsh winds spread the flames and low humidity left the forest full of fuel. But residents and experts also pointed their fingers at a variety of policies that they said had contributed to wildfires that seem to have grown in intensity over the years.
Some complained that it was environmentalists who had caused the forests to become tinderboxes by preventing the thinning of trees as they sought to protect wildlife. Others, like William Wallace Covington, a forestry expert at Northern Arizona University, countered that the leading factor was the grazing of forest grass for generations. The government’s longstanding practice of quickly extinguishing forest fires was also seen as adding to the thick clusters of highly combustible trees.
Seriously.
You would never know from the NYT that this standard right-wing talking point has actually been examined in the scientific literature and found wanting. Back in 2006, Science magazine published a major article analyzing whether the recent soaring wildfire trend was due to a change in forest management practices or to climate change. The study, led by the Scripps Institute of Oceanography, concluded:
Robust statistical associations between wildfire and hydroclimate in western forests indicate that increased wildfire activity over recent decades reflects sub-regional responses to changes in climate. Historical wildfire observations exhibit an abrupt transition in the mid-1980s from a regime of infrequent large wildfires of short (average of 1 week) duration to one with much more frequent and longer burning (5 weeks) fires. This transition was marked by a shift toward unusually warm springs, longer summer dry seasons, drier vegetation (which provoked more and longer burning large wildfires), and longer fire seasons. Reduced winter precipitation and an early spring snowmelt played a role in this shift.
That 2006 study noted global warming (from human-caused emissions of greenhouse gases such as carbon dioxide) will further accelerate all of these trends during this century.
http://www.youtube.com/watch?v=xhCY-3XnqS0&feature=player_embedded
continuedLast month, 350.org founder Bill McKibben published a must-read op-ed about the... more
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Carbon is pouring into Earth's atmosphere ten times faster today than during a dramatic event 56 million years ago that raised Earth's temperature by at least five degrees Celsius (nine degrees Fahrenheit), according to a study released Sunday.
That's not good news, geologists say, because the Paleocene-Eocene Thermal Maximum, or PETM, might have been a pre-historic dress rehearsal for a future climate change event that could be more abrupt and more damaging.
"Given that we are pumping carbon dioxide (CO2) into the atmosphere at a rate nearly ten times that of the PETM means that the climate system is having to adjust to a much more intense disturbance," said Lee Kump, a professor at Penn State University and a co-author of the study.
The PETM unfolded over a period of at least 10,000 years, more likely 20,000, according to the new research.
That's a blink of the eye in geological time, but was long enough for animals and plants to adapt. At least most of them -- a significant slice of deep sea life went extinct.
What worries scientists is that an accelerated version of this scenario may be playing out today.
"Since life is as sensitive to the rates of change as to the absolute amount of change, fossil-fuel burning is likely disrupting natural ecosystems at a global scale in a way that may have little precedence in Earth history," Kump said in an email exchange.
UN scientists have said that unless CO2 emissions are hugely reduced, average global temperatures could climb 4.0 to 5.0 C (7.2 to 9.0 F) by 2100, effectively compressing the PETM spike onto a scale of hundreds, rather than thousands of years.
If the PETM was a climate change "squeeze," while the asteroid that wiped out the dinosaurs 10 million years earlier was a "punch," we are "probably closer to the punch than the squeeze," Kump said.
Geologists have long known that a massive release of carbon caused the PETM, but where the carbon came from, exactly how much was released, and how quickly, were still subject to speculation.
Part of the problem was that rock and sediment samples from areas that were deep sea 55.9 million years ago are almost always highly compressed into a metre (three feet) at most, and thus hard to read.
Kump and colleagues, however, analysed a spot near Spitsbergen, Norway -- uncovered by a coal-mining operation -- where the PETM record is 150 metres (492 feet thick), and thus laden with fresh geological clues.
The site revealed that carbon emissions during the 20,000-year warming period did not exceed 1.7 billion metric tonnes per year, somewhat less than previously thought.
By comparison, recent fossil fuel emissions of carbon average over eight billion tonnes, with 2010 showing the highest output on record.
The findings "provides further support for the idea that it is the rapid rate at which we are dumping carbon that is so dangerous, as well as the large volumes involved," said Cambridge University professor Bryan Lovell, whose recent book "Challenged by Carbon" examines the PETM in detail.Carbon is pouring into Earth's atmosphere ten times faster today than during a... more
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Excerpt:
"An increase in heavy precipitation that has afflicted many countries is at least partly a consequence of human influence on the atmosphere, climate scientists reported in a new study.
In the first major paper of its kind, the researchers used elaborate computer programs that simulate the climate to analyze whether the rise in severe rainstorms, heavy snowfalls and similar events could be explained by natural variability in the atmosphere. They found that it could not, and that the increase made sense only when the computers factored in the effects of greenhouse gases released by human activities like the burning of fossil fuels.
As reflected in previous studies, the likelihood of extreme precipitation on any given day rose by about 7 percent over the last half of the 20th century, at least for the land areas of the Northern Hemisphere for which sufficient figures are available to do an analysis.
The principal finding of the new study is “that this 7 percent is well outside the bounds of natural variability,” said Francis W. Zwiers, a Canadian climate scientist who took part in the research. The paper is being published in Thursday’s edition of the journal Nature.
The paper covers climate trends from 1951 to 1999 and therefore does not include any analysis of last year’s extreme precipitation, including catastrophic floods in Pakistan, China and Australia as well as parts of the United States, including Tennessee, Arkansas and California. However, the paper is likely to bolster a growing sense among climate scientists that events like the 2010 floods will become more common.
Indeed, an increase of weather extremes has been a fundamental prediction of climate science for decades. Basic physics suggests that as the earth warms, precipitation extremes will become more intense, winter and summer, simply because warmer air can carry more water vapor. Weather statistics confirm that this has begun to happen.
Scientists have long been reluctant to attribute any specific weather event to global warming, but a handful of papers that do so are beginning to appear in the scientific literature. One such installment is being published on Thursday in Nature as a companion piece to the broader paper. It finds that severe rains that flooded England and Wales in 2000, the wettest autumn since record-keeping began there in 1766, were made substantially more likely by the greenhouse gases released by human activity.
In that analysis, scientists at the University of Oxford used computer time donated by the public to analyze the climate of Britain in 2000 as it actually existed and to compare that with a hypothetical climate in which the Industrial Revolution never happened and few greenhouse gases were released.
The computers found that the chances of those memorable floods, which sent geese swimming through city streets, were roughly doubled in a climate with the greenhouse gases.
That it took a decade to come to that conclusion illustrates one of the major problems of climate science at the moment. Researchers are barraged with questions about weather extremes like the recent winters in Europe and the United States and the heat waves and droughts of last summer."
_cont.______________________________Excerpt:
"An increase in heavy precipitation that has afflicted many countries... more
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The world's largest tropical forest, the Amazon, experienced something rare last year —a drought. It wasn't the earth-cracking kind of drought that happens in the American Southwest or the Australian outback, but it did stunt or kill lots of trees.
It was the second such drought in the Amazon in five years, and forest scientists are trying to understand why these droughts are happening, and what their effects will be for the planet.
The 2005 drought in the Amazon was so unusual that scientists called it a "100-year event" — something supposed to happen only once a century.
"This is what's quite alarming — that we've seen these two very unusual events," says Simon Lewis, a forest ecologist at the University of Leeds in Great Britain, who watched both droughts hit the Amazon. Lewis notes that several of the computer models that calculate the effects of climate change do predict that parts of the planet are going to get drier.
"And those two unusual events are consistent with those predictions that suggest that the Amazon may be severely impacted over the next few decades by these droughts," he says.
How Droughts Affect Forests
Writing in the journal Science, Lewis and his scientific team say the droughts are probably caused by the northward movement of especially warm water in the Atlantic Ocean. That shift carries moisture north, robbing big chunks of the Amazon of rain it normally would get.
The droughts can create a different forest — thinner, smaller and with a different mix of tree species. That, in turn, could affect the Earth's climate. As trees grow, they suck carbon dioxide out of the atmosphere and store it, so a big forest like the Amazon is a carbon "sink."
But drought slows that process down — more carbon remains in the atmosphere, and that could warm the planet.
If the forest gets dry enough, air can get into the vessels that carry water through a tree — kind of like an air bubble in a fuel line — and a tree dies. If enough die, that too could affect the atmosphere.
"As these dead trees rot and release their carbon in their trunks and roots into the atmosphere as carbon dioxide, then we see it probably turning into a source of carbon emissions," Lewis says.The world's largest tropical forest, the Amazon, experienced something rare last... more
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A widespread drought in the Amazon rainforest last year caused the "lungs of the world" to produce more carbon dioxide than they absorbed, potentially leading to a dangerous acceleration of global warming. Scientists have calculated that the 2010 drought was more intense than the "one-in-100-year" drought of 2005.
They are predicting it will result in some eight billion tonnes of carbon dioxide being expelled from the Amazon rainforest, which is more than the total annual carbon emissions of the United States. For the second time in less than a decade, the earth's greatest rainforest released more carbon dioxide than it absorbed because many of its trees dried out and died.
Scientists believe that the highly unusual nature of the two droughts, which occurred in the space of just five years, may be the result of higher sea-surface temperatures in the tropical Atlantic, which could also be influenced by global warming caused by the release of man-made emissions of carbon dioxide and other greenhouse gases. The Anglo-Brazilian team of researchers has emphasised that there is as yet no proof that the two highly unusual droughts in the Amazon are the direct result of rising carbon dioxide levels in the atmosphere, but the scientists have warned that the world is gambling with its future if it fails to curb fossil fuel emissions.
Simon Lewis of Leeds University, the lead author of the study, said: "If greenhouse gas emissions contribute to Amazon droughts that in turn cause forests to release carbon, this feedback loop would be extremely concerning. Put more starkly, current emissions pathways risk playing Russian roulette with the world's largest rainforest.
"Two unusual and extreme droughts occurring within a decade may largely offset the carbon absorbed by intact Amazon forests during that time. If events like this happen more often, the Amazon rainforest would reach a point where it shifts from being a valuable carbon sink slowing climate change to a major source of greenhouse gases that could speed it up. Having two events of this magnitude in such close succession is extremely unusual, but is unfortunately consistent with those climate models that project a grim future for Amazonia."
cont.A widespread drought in the Amazon rainforest last year caused the "lungs of the... more
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This is also affected by the Beaufort Gyre.
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Scientists have established a link between the cold, snowy winters in Britain and melting sea ice in the Arctic and have warned that long periods of freezing weather are likely to become more frequent in years to come.
An analysis of the ice-free regions of the Arctic Ocean has found that the higher temperatures there caused by global warming, which have melted the sea ice in the summer months, have paradoxically increased the chances of colder winters in Britain and the rest of northern Europe.
The findings are being assessed by British climate scientists, who have been asked by ministers for advice on whether the past two cold winters are part of a wider pattern of climate change that will cause further damaging disruption to the nation's creaking transport infrastructure.
Some climate scientists believe that the dramatic retreat of the Arctic sea ice over the past 30 years has begun to change the wind patterns over much of the northern hemisphere, causing cold, Arctic air to be funnelled over Britain during winter, replacing the mild westerly airstream that normally dominates the UK's weather.
The study was carried out in 2009, before last year's harsh winter started to bite, and is all the more prescient because of its prediction that cold, snowy winters will be about three times more frequent in the coming years compared to previous decades.
The researchers used computer models to assess the impact of the disappearing Arctic sea ice, particularly in the area of the Barents and Kara seas north of Scandinavia and Russia, which have experienced unprecedented losses of sea ice during summer.
Their models found that, as the ice cap over the ocean disappeared, this allowed the heat of the relatively warm seawater to escape into the much colder atmosphere above, creating an area of high pressure surrounded by clockwise-moving winds that sweep down from the polar region over Europe and the British Isles. Vladimir Petoukhov, who carried out the study at the Potsdam Institute for Climate Impact Research in Germany, said the computer simulations showed that the disappearing sea ice is likely to have widespread and unpredictable impacts on the climate of the northern hemisphere.
One of the principal predictions of the study was that the warming of the air over the ice-free seas is likely to bring bitterly cold air to Europe during the winter months, Dr Petoukhov said. "This is not what one would expect. Whoever thinks that the shrinking of some far away sea-ice won't bother him could be wrong. There are complex interconnections in the climate system, and in the Barents-Kara Sea we might have discovered a powerful feedback mechanism," he said.
In the paper, submitted in November 2009 but published last month in the Journal of Geophysical Research, Dr Petoukhov and his colleague Vladimir Semenov write: "Our results imply that several recent severe winters do not conflict with the global warming picture but rather supplement it."
Arctic sea ice has been in retreat over recent decades, with record lows recorded in September 2007. The normal recovery of the sea ice during winter has also been affected, especially in the Barents and Kara seas which have seen significant losses of ice cover over the past decade.
cont.
http://climateprogress.org/2010/09/15/noaa-2010-hottest-year-global-warming/
Herein lies the paradox. So don't be fooled by those who will use this information to state there is no global warming because all they know is what they see out their own windows and who really don't know science regardless of how many times they try to pretend to you that they do.Scientists have established a link between the cold, snowy winters in Britain and... more
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Arctic sea ice melted over the summer to cover the third smallest area on record, US researchers said Wednesday, warning global warming could leave the region ice free in the month of September 2030.
Last week, at the end of the spring and summer "melt season" in the Arctic, sea ice covered 4.76 million square kilometers (1.84 million square miles), the University of Colorado's National Snow and Ice Data Center said in an annual report.
"This is only the third time in the satellite record that ice extent has fallen below five million square kilometers (1.93 million square miles), and all those occurrences have been within the past four years," the report said.
A separate report by the National Oceanic and Atmospheric Administration (NOAA) found that in August, too, Arctic sea ice coverage was down sharply, covering an average of six million square kilometers (2.3 million square miles), or 22 percent below the average extent from 1979 to 2000.
The August coverage was the second lowest for Arctic sea ice since records began in 1979. Only 2007 saw a smaller area of the northern sea covered in ice in August, NOAA said.
The record low for Arctic sea ice cover at the end of the spring and summer "melt season" in September, was also in 2007, when ice covered just 4.13 million square kilometers (1.595 million square miles).
Mark Serreze, director of the NSIDC, said climate-change skeptics might seize the fact that Arctic sea ice did not hit a record-low extent this year, but said they would be barking up the wrong tree if they claimed the shrinkage had been stopped.
"Only the third lowest? It didn't set a new record? Well, right. It didn't set a new record but we're still headed down. We're not looking at any kind of recovery here," he told AFP.
In fact, Serreze said, Arctic sea ice cover is shrinking year-round, with more ice melting in the spring and summer months and less ice forming in the fall and winter.
"The Arctic, like the globe as a whole, is warming up and warming up quickly, and we're starting to see the sea ice respond to that. Really, in all months, the sea ice cover is shrinking -- there's an overall downward trend," Serreze told AFP.
"The extent of Arctic ice is dropping at something like 11 percent per decade -- very quickly, in other words.
"Our thinking is that by 2030 or so, if you went out to the Arctic on the first of September, you probably won't see any ice at all. It will look like a blue ocean, we're losing it that quickly," he said.
Losing sea ice cover in the Arctic would affect everything from the obvious, such as people who live in the far north and polar bears, to global weather patterns, said Serreze.
"The Arctic acts as a sort of refrigerator of the northern hemisphere. As we lose the ice cover, we start to change the nature of that refrigerator, and what happens up there affects what happens down here in the middle latitudes," he said.
"We might have less cold outbreaks, which you might say is a good thing, but it's not such a good thing in regions that depend on snowfall for their water supply."
NOAA noted in its report that the first eight months of 2010 were in equal first place with the same period in 1998 for the warmest combined land and ocean surface temperatures on record worldwide, and the summer months were the second warmest on record globally, after 1998.Arctic sea ice melted over the summer to cover the third smallest area on record, US... more
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