The University of Alaska is on the forefront of global warming/climate change research, as the Arctic regions are experiencing some of the most rapid changes on the planet (the other most rapidly changing place is the northerly reaches of Antarctica). http://amap.no/acia/
Thus, we here at A.P.R. feel it is imperative to share the latest state of the science information regarding our changing climate and atmospheric/oceanic systems. Because rapid action is urgently necessary to limit CO2 and methane emissions from fossil fuel combustion and deforestation, before so-called "positive-feedback" processes overwhelm the climate system and initiate runaway warming processes. The results of which would be greatly disastrous for all on our planet. BAD NEWS.
http://www.guardian.co.uk/books/2008/apr/26/featuresreviews.guardianreview16
ardianreview16You might remember seeing some graphs like these, if you saw The Inconvenient Truth, the movie Al Gore, our ex-2000 president (if there had been a real election), helped to make. We here at A.P.R. viewed this movie as extremely important in documenting the climate change problem, and felt it was an accurate depiction of the state of the science.
http://www.climatecrisis.net/
The figure to the right is from the Arctic Climate Impact Assessment, and shows the expected changes in CO2 concentrations, and resultant warming, by 2100. As you can see, barring any significant reductions in current emissions (which seems likely, unfortunately), average temperature increases in the Arctic of 6C or more are likely by 2100. Which follows exactly the trend of concentrations of CO2 in the atmosphere.
Which is what this figure shows. The concentration of CO2 over the past 1000 years (measured from bubbles of air in glacier ice cores world-wide) has varied littl
e until around 1900. And likewise global mean temperatures (reconstructed from a variety of sources, glacial ice, tree-ring analysis, etc..) have varied little, until after 1900. And the trend of increasing temperature matches exactly, that of the increasing CO2 concentration.With all that in mind, what has been happening, and is happening, here in Alaska, with global warming?
Well, let's take a look at a few things.
This image shows the total change in mean annual temperatures throughout Alaska since 1949. Note how significant changes of 2.5F to 5.0F have occurred across the entire state.
http://climate.gi.alaska.edu/ClimTrends/Change/TempChange.html
Even more interesting is the seasonal breakdown of these increases. Note how most areas have experienced the greatest warming in the winter season (Fairbanks and the interior, 7 to 9F increases!). Now, that has made it easier living here, fewer days of deep cold, for example (the -30F or colder ones especially). But this comes at a price. Permafrost thawing is also occuring as a result, which has and will even more greatly affect roads and infrastructure. In addition, thawing permafrost releases more CO2 and methane, a "positive feedback".How is this warming manifesting here in Alaska? One thing we are seeing, are increasing frequencies of stronger high pressure ridging, throughout the year. High pressure ridging refers to the flow patterns in the jet stream, the meandering generally westerly overall atmospheric circulation between the subtropics and the polar regions, that transports heat poleward, and cold equator-ward, to maintain an overall temperature balance. High pressure ridging is when warmer air in the Northern Hemisphere moves northward in the jet stream, forming a "ridge" in the circulation pattern, which is just a bubble, or large mass, of warm air. Above average temperatures occur with a ridge pattern, and usually dry weather, though in summer, on it's edges, sometimes enough moisture and instability will be present to generate thunderstorms (and thus, start more fires!). One other thing to mention as well, about stronger, and more persistent high pressure ridging patterns is this. Up and downstream from a high pressure ridge, there are low pressure troughs. If an area is under a low pressure trough, blocked from moving by a strong ridge, a spell of very wet weather can occur. In the right circumstances, this will lead to stronger storms and increased flooding episodes.
An excellent example of this occurred at the end of April this year here in Alaska and Northwest Canada, and was the subject of our "Yea
r Without a Spring?" post. This strong high pressure ridge, which built north from the subtropics, brought temperatures in the 70sF to interior Alaska abruptly at the end of April, after just an average slowly thawing month, with snowpacks and river ice just gradually thinning, as is usually the case. The rapid warmth sent a surge of snowmelt into the waterways of the region, and the thick river ice began moving and jamming, causing extensive flooding. Many villages along the Yukon river experienced major damage from this occurrence, and are hectically trying to rebuild, before the still harsh sub-arctic winter sets in.http://akprogressive.blogspot.com/2009/05/year-without-spring.html
Then, there are our fire seasons. So far, since 2004, we have burned approximately 15 million acres in interior Alaska, 3 million this summer. This is abou
t 14 percent of the 110 million burnable acres in the region. You can see the trend in our wildfire acreages since 1955, around 1986 or so, a trend toward higher seasonal accumulations more frequently began, which has also been seen in Western Canada and the Western Lower 48.http://www.commondreams.org/headline/2009/08/24-6
This article, at the above website, describes the increasing fire trends in Canada and Siberia, so unfortunately, this trend, another positive feedback mechanism, is occurring globally. Greece is experiencing wildfire emergencies currently.
http://news.bbc.co.uk/2/hi/europe/8217433.stm
And, the tragic Australian fires last February, which caused 173 fatalities (the worst natural disaster in that country's history), were the subject of our first "Warning Lights Are Flashing" post.
http://akprogressive.blogspot.com/2009/03/warning-lights-are-flashing-australia.html
Here are the perimeters of the 2009 fires in Interior Alaska. I worked on the very largest one, southwest of Fairbanks, the Railbelt Complex, forecasting weather for the suppression team this past July, for two weeks, when it was "only" 150,000 to 350,000 acres. It eventually grew to over 600,000.
What caused this large fire season of 3 million acres? And the emergencies in Greece and Australia, and our record 2004/2005 fire seasons?
Anomalously strong and persistent high pressure ridging.
High pressure ridging covered Alaska and Northwest Canada from late June through the entire month of July. Fairbanks had it's driest July ever, since records began in 1904 (and driest summer month ever!), with only .06.
Fairbanks also picked up it's first day over 90F since 1994 this summer, when the temperature reached 91F on 08 July. And, as you can see from this figure, most of the days of the month had above average high and low temperatures.
So there you have it. The warming climate in the Arctic is occurring because stronger, more frequent, and more persistent high pressure ridging episodes are transporting greater amounts of heat northward. Since we've only warmed 1-2C over the past 60 years, another 4-6C of warming would therefore mean a strong amplification of this high pressure ridging pattern occurrence. Meaning, stronger more frequent warm spells, and all the ramifications thereof.
Here are some articles detailing changes occurring for the Arctic as a whole, which are very interesting and alarming.
Climate change hitting entire Arctic ecosystem, says report
Extensive climate change is now affecting every form of life in the Arctic, according to a major new assessment by international polar scientists.
In the past four years, air temperatures have increased, sea ice has declined sharply, surface waters in the Arctic ocean have warmed and permafrost is in some areas rapidly thawing.
In addition, says the report released today at a Norwegian government seminar, plants and trees are growing more vigorously, snow cover is decreasing 1-2% a year and glaciers are shrinking.
In addition, says the report released today at a Norwegian government seminar, plants and trees are growing more vigorously, snow cover is decreasing 1-2% a year and glaciers are shrinking.
Scientists from Norway, Canada, Russia and the US contributed to the Arctic monitoring and assessment programme (Amap) study, which says new factors such as "black carbon" – soot – ozone and methane may now be contributing to global and arctic warming as much as carbon dioxide.
"Black carbon and ozone in particular have a strong seasonal pattern that makes their impacts particularly important in the Arctic," it says.
The report's main findings are:
Land
Permafrost is warming fast and at its margins thawing. Plants are growing more vigorously and densely. In northern Alaska, temperatures have been rising since the 1970s. In Russia, the tree line has advanced up hills and mountains at 10 metres a year. Nearly all glaciers are decreasing in mass, resulting in rising sea levels as the water drains to the ocean.
Permafrost is warming fast and at its margins thawing. Plants are growing more vigorously and densely. In northern Alaska, temperatures have been rising since the 1970s. In Russia, the tree line has advanced up hills and mountains at 10 metres a year. Nearly all glaciers are decreasing in mass, resulting in rising sea levels as the water drains to the ocean.
Summer sea ice
The most striking change in the Arctic in recent years has been the reduction in summer sea ice in 2007. This was 23% less than the previous record low of 5.6m sq kilometres in 2005, and 39% below the 1979-2000 average. New satellite data suggests the ice is much thinner than it used to be. For the first time in existing records, both the north-west and north-east passages were ice-free in summer 2008. However, the 2008 winter ice extent was near the year long-term average.
The most striking change in the Arctic in recent years has been the reduction in summer sea ice in 2007. This was 23% less than the previous record low of 5.6m sq kilometres in 2005, and 39% below the 1979-2000 average. New satellite data suggests the ice is much thinner than it used to be. For the first time in existing records, both the north-west and north-east passages were ice-free in summer 2008. However, the 2008 winter ice extent was near the year long-term average.
Greenland
The Greenland ice sheet has continued to melt in the past four years with summer temperatures consistently above the long-term average since the mid 1990s. In 2007, the area experiencing melt was 60% greater than in 1998. Melting lasted 20 days longer than usual at sea level and 53 days longer at 2-3,000m heights.
The Greenland ice sheet has continued to melt in the past four years with summer temperatures consistently above the long-term average since the mid 1990s. In 2007, the area experiencing melt was 60% greater than in 1998. Melting lasted 20 days longer than usual at sea level and 53 days longer at 2-3,000m heights.
Warmer waters
In 2007, some ice-free areas were as much as 5C warmer than the long-term average. Arctic waters appear to have warmed as a result of the influx of warmer waters from the Pacific and Atlantic. The loss of reflective, white sea ice also means that more solar radiation is absorbed by the dark water, heating surface layers further.
Black carbon
Black carbon, or soot, is emitted from inefficient burning such as in diesel engines or from the burning of crops. It is warming the Arctic by creating a haze which absorbs sunlight, and it is also deposited on snow, darkening the surface and causing more sunlight to be absorbed.
Black carbon, or soot, is emitted from inefficient burning such as in diesel engines or from the burning of crops. It is warming the Arctic by creating a haze which absorbs sunlight, and it is also deposited on snow, darkening the surface and causing more sunlight to be absorbed.
Check out the image to the right. An Arctic sea ice image from 20 August, 1980, next to one from 20 August, 2009. Can you see the differences? They are very significant. Here is the lastest Arctic sea ice update from the National Snow and Ice Data center:
ARCTIC SEA ICE UPDATE
"During the first half of August, Arctic ice extent declined more slowly than during the same period in 2007 and 2008. The slower decline is primarily due to a recent atmospheric circulation pattern, which transported ice toward the Siberian coast and discouraged export of ice out of the Arctic Ocean. It is now unlikely that 2009 will see a record low extent, but the minimum summer ice ext
ent will still be much lower than the 1979 to 2000 average.
ent will still be much lower than the 1979 to 2000 average.Overview of conditions
On August 17, Arctic sea ice extent was 6.26 million square kilometers (2.42 million square miles). This is 960,000 square kilometers (370,000 square miles) more ice than for the same day in 2007, and 1.37 million square kilometers (530,000 square miles) below the 1979 to 2000 average. On August 8, the 2009 extent decreased below the 1979 to 2000 average minimum annual extent, with a month of melt still remaining."
Unfortunately, the news keeps getting worse. Both the increasing wildfire acreage trends across the Northern Hemisphere, and this decreasing Arctic sea ice coverage are positive feedback mechanisms. The sea ice coverage because decreasing areas allow more heat to be absorbed by the water, which retains the heat longer, which delays freezing longer in the fall. The new ice over the winter freezes thinner, and melts off sooner the next year. And so on...
This next article though describes what we think is the most ominous finding to date. Because if methane clathrate deposits from the seafloor are really melting now and releasing methane gas into the ocean (and eventually into the atmosphere), runaway warming is nearly upon us. Methane is 22 times more efficient of a greenhouse gas than carbon dioxide, and rapid increases in its atmospheric concentration will rapidly amplify warming, warming ocean waters further, triggering more methane releases, etc.. There are no mechanisms known that could stop this, once it starts.
http://news.bbc.co.uk/2/hi/science/nature/8205864.stm
Methane seeps from Arctic sea-bed
By Judith Burns Science and environment reporter, BBC News
Methane bubbles observed by sonar, escape from sea-bed as temperatures rise
Scientists say they have evidence that the po
werful greenhouse gas methane is escaping from the Arctic sea-bed.
Methane seeps from Arctic sea-bed
By Judith Burns Science and environment reporter, BBC News
Methane bubbles observed by sonar, escape from sea-bed as temperatures rise
Scientists say they have evidence that the po
werful greenhouse gas methane is escaping from the Arctic sea-bed. Researchers say this could be evidence of a predicted positive feedback effect of climate change.
As temperatures rise, the sea-bed grows warmer and frozen water crystals in the sediment break down, allowing methane trapped inside them to escape.
The research team found that more than 250 plumes of methane bubbles are rising from the sea-bed off Norway.
The joint British and German research team detected the bubbles using a type of sonar normally used to search for shoals of fish. Once detected, the bubbles were sampled and tested for methane at a range of depths.
Writing in Geophysical Research Letters, the team says the methane was rising from an area of sea-bed off West Spitsbergen, from depths between 150m and 400m.
The gas is normally trapped as "methane hydrate" in sediment under the ocean floor.
METHANE HYDRATES
METHANE HYDRATES
Methane gas is trapped inside a crystal structure of water-ice
The gas is released when the ice melts, normally at 0C
At higher pressure, ie under the ocean, hydrates are stable at higher temperatures
"Methane hydrate" is an ice-like substance composed of water and methane which is stable under conditions of high pressure and low temperature.
As temperatures rise, the hydrate breaks down. So this new evidence shows that methane is stable at water depths greater than 400m off Spitsbergen.
However, data collected over 30 years shows it was then stable at water depths as shallow as 360m.
Ocean has warmed
Temperature records show that this area of the ocean has warmed by 1C during the same period.
The research was carried out as part of the International Polar Year Initiative, funded by Britain's Natural Environment Research Council (Nerc).
The team says this is the first time that this loss of stability associated with temperature rise has been observed during the current geological period.
Professor Tim Minshull of the National Oceanography Centre at Southampton told BBC News: "We already knew there was some methane hydrate in the ocean off Spitsbergen and that's an area where climate change is happening rather faster than just about anywhere else in the world."
1. Methane hydrate is stable below 400m
2. Nearer the surface the hydrate breaks down as temperatures rise and the methane is released
3. Gas rises from the sea-bed in plumes of bubbles - most of it dissolves before it reaches the surface
4. So far scientists haven't detected methane breaking the ocean surface - but they don't rule out the possibility
1. Methane hydrate is stable below 400m
2. Nearer the surface the hydrate breaks down as temperatures rise and the methane is released
3. Gas rises from the sea-bed in plumes of bubbles - most of it dissolves before it reaches the surface
4. So far scientists haven't detected methane breaking the ocean surface - but they don't rule out the possibility
"There's been an idea for a long time that if the oceans warm, methane might be released from hydrate beneath the sea floor and generate a positive greenhouse effect.
"What we're trying to do is to use lots of different techniques to assess whether this was something that was likely to happen in a relatively short time scale off Spitsbergen."
However, methane is already released from ocean floor hydrates at higher temperatures and lower pressures - so the team also suggests that some methane release may have been going on in this area since the last ice age.
Significant discovery
Their most significant finding is that climate change means the gas is being released from more and deeper areas of the Arctic Ocean.
Professor Minshull said: "Our survey was designed to work out how much methane might be released by future ocean warming; we did not expect to discover such strong evidence that this process has already started."
"We were slightly surprised that if there was so much methane rising why no one had seen it before. But I think the reason is that you have to be rather dedicated to spot it because these plumes are only perhaps 50m to 100m across.
"The device we were using is only switched on during biological cruises. It's not normally used on geophysical or oceanographic cruises like ours. And of course you've got to monitor it 24 hours a day. In fact, we only spotted the phenomenon half way through our cruise. We decided to go back and take a closer look."
The team found that most of the methane is being dissolved into the seawater and did not detect evidence of the gas breaking the surface of the ocean and getting into the atmosphere.
The researchers stress that this does not mean that the gas does not enter the atmosphere. They point out that the methane seeps are unpredictable and erratic in quantity, size and duration.
It is possible that larger seeps at different times and locations might in fact be vigorous enough to break through the ocean surface.
Most of the methane reacts with the oxygen in the water to form carbon dioxide, another greenhouse gas. In sea water, this forms carbonic acid which adds to ocean acidification, with consequent problems for biodiversity.
Graham Westbrook, lead author and professor of geophysics at the University of Birmingham, said: "If this process becomes widespread along Arctic continental margins, tens of megatonnes of methane a year - equivalent to 5-10% of the total amount released globally by natural sources, could be released into the ocean."
The team is planning another expedition next year to observe the behaviour of the methane plumes over time. They are also engaged in ongoing research into the amount of methane hydrate under this area of the ocean floor.
Ultimately, they want to be able to predict how much might be vulnerable to temperature change and in what timescale.
As the next article shows, warming ocean waters are breaking records. Combined with the news from the previous article, describing the Arctic seafloor methane releases, we here at A.P.R. are very alarmed.
http://www.commondreams.org/headline/2009/08/20-13
Hot Water: World Sets Ocean Temperature Record
by Seth Borenstein
WASHINGTON — Steve Kramer spent an hour and a half swimming in the ocean Sunday — in Maine. The water temperature was 72 degrees — more like Ocean City, Md., this time of year. And Ocean City's water temp hit 88 degrees this week, toasty even by Miami Beach standards.
Kramer, 26, who lives in the seaside town of Scarborough, said it was the first time he's ever swam so long in Maine's coastal waters. "Usually, you're in five minutes and you're out," he said.
It's not just the ocean off the Northeast coast that is super-warm this summer. July was the hottest the world's oceans have been in almost 130 years of record-keeping.
The average water temperature worldwide was 62.6 degrees, according to the National Climatic Data Center, the branch of the U.S. government that keeps world weather records. June was only slightly cooler, while August could set another record, scientists say. The previous record was set in July 1998 during a powerful El Nino weather pattern.
Meteorologists said there's a combination of forces at work: A natural El Nino system just getting started on top of worsening man-made global warming, and a dash of random weather variations. The resulting ocean heat is already harming threatened coral reefs. It could also hasten the melting of Arctic sea ice and help hurricanes strengthen.
The Gulf of Mexico, where warm water fuels hurricanes, has temperatures dancing around 90. Most of the water in the Northern Hemisphere has been considerably warmer than normal. The Mediterranean is about three degrees warmer than normal. Higher temperatures rule in the Pacific and Indian Oceans.
The heat is most noticeable near the Arctic, where water temperatures are as much as 10 degrees above average. The tongues of warm water could help melt sea ice from below and even cause thawing of ice sheets on Greenland, said Waleed Abdalati, director of the Earth Science and Observation Center at the University of Colorado.
Breaking heat records in water is more ominous as a sign of global warming than breaking temperature marks on land, because water takes longer to heat up and does not cool off as easily as land.
"This warm water we're seeing doesn't just disappear next year; it'll be around for a long time," said climate scientist Andrew Weaver of the University of Victoria in British Columbia. It takes five times more energy to warm water than land.
The warmer water "affects weather on the land," Weaver said. "This is another yet really important indicator of the change that's occurring."
Georgia Institute of Technology atmospheric science professor Judith Curry said water is warming in more places than usual, something that has not been seen in more than 50 years.
Add to that an unusual weather pattern this summer where the warmest temperatures seem to be just over oceans, while slightly cooler air is concentrated over land, said Deke Arndt, head of climate monitoring at the climate data center.
The pattern is so unusual that he suggested meteorologists may want to study that pattern to see what's behind it.
The effects of that warm water are already being seen in coral reefs, said C. Mark Eakin, coordinator of the National Oceanic and Atmospheric Administration's coral reef watch. Long-term excessive heat bleaches colorful coral reefs white and sometimes kills them.
Bleaching has started to crop up in the Florida Keys, Puerto Rico and the Virgin Islands — much earlier than usual. Typically, bleaching occurs after weeks or months of prolonged high water temperatures. That usually means September or October in the Caribbean, said Eakin. He found bleaching in Guam Wednesday. It's too early to know if the coral will recover or die. Experts are "bracing for another bad year," he said.
The problems caused by the El Nino pattern are likely to get worse, the scientists say.
An El Nino occurs when part of the central Pacific warms up, which in turn changes weather patterns worldwide for many months. El Nino and its cooling flip side, La Nina, happen every few years.
During an El Nino, temperatures on water and land tend to rise in many places, leading to an increase in the overall global average temperature. An El Nino has other effects, too, including dampening Atlantic hurricane formation and increasing rainfall and mudslides in Southern California.
Warm water is a required fuel for hurricanes. What's happening in the oceans "will add extra juice to the hurricanes," Curry said.
Hurricane activity has been quiet for much of the summer, but that may change soon, she said. Hurricane Bill quickly became a major storm and the National Hurricane Center warned that warm waters are along the path of the hurricane for the next few days.
Hurricanes need specific air conditions, so warmer water alone does not necessarily mean more or bigger storms, said James Franklin, chief hurricane specialist at the National Hurricane Center in Miami.
by Seth Borenstein
WASHINGTON — Steve Kramer spent an hour and a half swimming in the ocean Sunday — in Maine. The water temperature was 72 degrees — more like Ocean City, Md., this time of year. And Ocean City's water temp hit 88 degrees this week, toasty even by Miami Beach standards.
Kramer, 26, who lives in the seaside town of Scarborough, said it was the first time he's ever swam so long in Maine's coastal waters. "Usually, you're in five minutes and you're out," he said.
It's not just the ocean off the Northeast coast that is super-warm this summer. July was the hottest the world's oceans have been in almost 130 years of record-keeping.
The average water temperature worldwide was 62.6 degrees, according to the National Climatic Data Center, the branch of the U.S. government that keeps world weather records. June was only slightly cooler, while August could set another record, scientists say. The previous record was set in July 1998 during a powerful El Nino weather pattern.
Meteorologists said there's a combination of forces at work: A natural El Nino system just getting started on top of worsening man-made global warming, and a dash of random weather variations. The resulting ocean heat is already harming threatened coral reefs. It could also hasten the melting of Arctic sea ice and help hurricanes strengthen.
The Gulf of Mexico, where warm water fuels hurricanes, has temperatures dancing around 90. Most of the water in the Northern Hemisphere has been considerably warmer than normal. The Mediterranean is about three degrees warmer than normal. Higher temperatures rule in the Pacific and Indian Oceans.
The heat is most noticeable near the Arctic, where water temperatures are as much as 10 degrees above average. The tongues of warm water could help melt sea ice from below and even cause thawing of ice sheets on Greenland, said Waleed Abdalati, director of the Earth Science and Observation Center at the University of Colorado.
Breaking heat records in water is more ominous as a sign of global warming than breaking temperature marks on land, because water takes longer to heat up and does not cool off as easily as land.
"This warm water we're seeing doesn't just disappear next year; it'll be around for a long time," said climate scientist Andrew Weaver of the University of Victoria in British Columbia. It takes five times more energy to warm water than land.
The warmer water "affects weather on the land," Weaver said. "This is another yet really important indicator of the change that's occurring."
Georgia Institute of Technology atmospheric science professor Judith Curry said water is warming in more places than usual, something that has not been seen in more than 50 years.
Add to that an unusual weather pattern this summer where the warmest temperatures seem to be just over oceans, while slightly cooler air is concentrated over land, said Deke Arndt, head of climate monitoring at the climate data center.
The pattern is so unusual that he suggested meteorologists may want to study that pattern to see what's behind it.
The effects of that warm water are already being seen in coral reefs, said C. Mark Eakin, coordinator of the National Oceanic and Atmospheric Administration's coral reef watch. Long-term excessive heat bleaches colorful coral reefs white and sometimes kills them.
Bleaching has started to crop up in the Florida Keys, Puerto Rico and the Virgin Islands — much earlier than usual. Typically, bleaching occurs after weeks or months of prolonged high water temperatures. That usually means September or October in the Caribbean, said Eakin. He found bleaching in Guam Wednesday. It's too early to know if the coral will recover or die. Experts are "bracing for another bad year," he said.
The problems caused by the El Nino pattern are likely to get worse, the scientists say.
An El Nino occurs when part of the central Pacific warms up, which in turn changes weather patterns worldwide for many months. El Nino and its cooling flip side, La Nina, happen every few years.
During an El Nino, temperatures on water and land tend to rise in many places, leading to an increase in the overall global average temperature. An El Nino has other effects, too, including dampening Atlantic hurricane formation and increasing rainfall and mudslides in Southern California.
Warm water is a required fuel for hurricanes. What's happening in the oceans "will add extra juice to the hurricanes," Curry said.
Hurricane activity has been quiet for much of the summer, but that may change soon, she said. Hurricane Bill quickly became a major storm and the National Hurricane Center warned that warm waters are along the path of the hurricane for the next few days.
Hurricanes need specific air conditions, so warmer water alone does not necessarily mean more or bigger storms, said James Franklin, chief hurricane specialist at the National Hurricane Center in Miami.
[Good News ? ]
Our last article to present describes some findings from Greenland, which does on the face of it, seem like good news:
http://scrippsnews.ucsd.edu/Releases/?releaseID=981
http://scrippsnews.ucsd.edu/Releases/?releaseID=981
FOR RELEASE ON Thursday, April 23, 2009 11:00 AM PDT 
Thursday, April 23, 2009
Wetlands Likely Source of Methane from Ancient Warming Event
Analysis of Greenland ice led by Scripps researchers could allay fears about methane 'burp' accelerating current global warming trend
Scripps Institution of Oceanography / University of California, San Diego
An expansion of wetlands and not a large-scale melting of frozen methane deposits is the likely cause of a spike in atmospheric methane gas that took place some 11,600 years ago, according to an international research team led by Scripps Institution of Oceanography at UC San Diego.
Scripps Institution of Oceanography geoscientist Jeff Severinghaus extracts blocks of ice from an ice sheet in Greenland.
Scripps Institution of Oceanography geoscientist Jeff Severinghaus extracts blocks of ice from an ice sheet in Greenland.
Severinghaus participated in an international analysis of methane trapped in the ice sheet to understand the origins of a sudden burst of atmospheric methane 11,600 years ago. Photo: Vas Petrenko, University of Colorado, Boulder
The finding is expected to come as a relief to scientists and climate watchers concerned that huge accelerations of global warming might have been touched off by methane melts in the past and could happen again now as the planet warms. By measuring the amount of carbon-14 isotopes in methane from air bubbles trapped in glacial ice, the researchers determined that the surge that took place nearly 12,000 years ago was more chemically consistent with an expansion of wetlands. Wetland regions, which produce large amounts of methane from bacterial breakdown of organic matter, are known to have spread during warming trends throughout history."This is good news for global warming because it suggests that methane clathrates do not respond to warming by releasing large amounts of methane into the atmosphere," said Vasilii Petrenko, a postdoctoral fellow at University of Colorado, Boulder, who led the analysis while a graduate student at Scripps.
The results appear in April 24 editions of the journal Science.
Scientists had long been concerned about the potential for present-day climate change to cause a thawing of Arctic permafrost and a warming of ocean waters great enough to trigger a huge release of methane that would send planetary warming into overdrive. Vast amounts of methane are sequestered in solid form, known as methane clathrate, in seafloor deposits and in permafrost. Cold temperatures and the intense pressure of the deep ocean stabilize the methane clathrate masses and keep methane from entering the atmosphere. Scientists have estimated that a melting of only 10 percent of the world's clathrate deposits would create a greenhouse effect equal to a tenfold increase in the amount of carbon dioxide in the atmosphere.
For comparison, the warming trend observed in the last century has taken place with only a 30 percent increase of atmospheric carbon dioxide.The research team, overseen by Scripps geoscientist and study co-author Jeff Severinghaus, collected what may be the largest ice samples ever for a climate change study. The researchers cut away 15 tons of ice from a site called Pakitsoq at the western margin of the Greenland ice sheet to collect the ancient air trapped within. Methane exists in low concentrations in this air and only a trillionth of any given amount contains the carbon-14 isotope that the researchers needed to perform the analysis. Levels of carbon-14, which has a half-life of 5,730 years, were too high in the methane to have come from clathrates, the researchers concluded.
Geoscientists Vas Petrenko and Jeff Severinghaus celebrated the acquisition of uncontaminated methane samples during field research at the Greenland ice sheet. The two helped determine that a burst of atmospheric methane 11,600 years ago was most likely caused by expansion of wetlands.
Geoscientists Vas Petrenko and Jeff Severinghaus celebrated the acquisition of uncontaminated methane samples during field research at the Greenland ice sheet. The two helped determine that a burst of atmospheric methane 11,600 years ago was most likely caused by expansion of wetlands.
"This study is important because it confirms that wetlands and moisture availability change dramatically along with abrupt climate change," said Severinghaus. "This highlights in a general way the fact that the largest impacts of future climate change may be on water resources and drought, rather than temperature per se."The burst of methane took place immediately after an abrupt transition between climatic periods known as the Younger Dryas and Preboreal. During this event, temperatures in Greenland rose 10° C (18° F) in 20 years. Methane levels over 150 years rose about 50 percent, from 500 parts per billion in air to 750 parts per billion.
In addition to Petrenko and Severinghaus, researchers from the Australian Nuclear Science and Technology Organisation (ANSTO), Oregon State University, the National Institute of Water and Atmospheric Research in New Zealand, the Technical University of Denmark and the Commonwealth Scientific and Industrial Research Organisation in Australia contributed to the report. The work was supported by grants from the National Science Foundation, the Packard Foundation, the American Chemical Society, the ANSTO Cosmogenic Climate Archives of the Southern Hemisphere project and the New Zealand Foundation of Science and Technology.
This may seem like good news, and possibly it is (let's hope so!). However, this article was written last April, based on research conducted a year previously. The article describing the Arctic seafloor methane releases just came out a few days ago. The researchers in Greenland from the Scripps Institute of Oceanography may not be aware of these latest findings. Massive surveying of the Arctic seafloor needs to be undertaken A.S.A.P., to ascertain if these methane releases are very widespread, and if they are increasing. As well as to measure how much, if any, is making it into the atmosphere.
Bad news all around. The industrialised nations are all dragging their feet about implementing any significant emission reduction plans, primarily due to extreme pressure from the fossil fuel and transportation industries. Who fund researchers and advertising campaigns to muddy the waters, so that the public and policy-makers will not feel that climate change is a pressing issue.
It now looks like it is too late to prevent extreme events such as sea level rises that will affect low-lying countries, droughts, and all the other effects of global warming (increasing wildfire severity, stronger tropical storms, increased flooding), SINCE THE POSITIVE FEEDBACK MECHANISMS ARE STARTING.
The only hope now is that once more people and politicians are directly affected, real attempts to solve the problem can be undertaken. Will it be too late?
Cheers.
1 comment:
Wow... great blog. Found you via CommonDreams.
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