Tuesday, February 06, 2007
Sunday, January 21, 2007
Swiss Glaciers melting rapidly
BRUSSELS - Receding Alpine glaciers are appearing a sure telltale of
global warming. In Switzerland, 84 out of 85 glaciers under observation
became shorter in 2006.The hot summers and the lack of precipitation in
recent years will accelerate the melting process even more, scientists
say.
Glaciers are large masses of snow, ice and rock debris that
accumulate in great quantities and begin to flow downwards under
pressure of their own weight. They are formed when yearly snowfall in a
region far exceeds the amount of snow and ice that melts in a given
summer, like in the Swiss Alps.
The results published by the Swiss Academy of Sciences confirm
the measurements of previous campaigns, which clearly showed that Swiss
glaciers are shrinking. Approximately three-quarters of the observed
shrinkage in 2006 is between one and 30 metres.
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Friday, January 19, 2007
Landmark UN Study Backs Climate Theory
A major new
United Nations report shows global scientists are more convinced than
ever that human activity is causing climate change, the Toronto Star has learned.
The rate of warming between now and 2030 is likely to be twice that of the previous century, it says.
And it concludes that most of the global warming since the middle ofthe last century has been caused by man-made greenhouse gases
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Warning from Stephen Hawking
Published: January 2007
Climate change stands alongside the use of nuclear weapons as one ofthe greatest threats posed to the future of the world, the Cambridge cosmologist Stephen Hawking has said
Professor Hawking said that we stand on the precipice of a second nuclearage and a period of exceptional climate change, both of which could destroythe planet as we know it.
Wednesday, January 17, 2007
Sweden's Tree Line Moving at Fastest Rate for 7,000 Years
http://www.commondreams.org/headlines07/0116-06.htm
Climate change
over the past two decades has caused Sweden's tree line to move north
at a faster rate than at any time in the past 7,000 years, Swedish
researchers have said.
![]() Autumn-coloured trees are pictured in the Swedish county of Jaemtland. Climate change over the past two decades has caused Sweden's tree line to move north at a faster rate than at any time in the past 7,000 years, Swedish researchers have said.(AFP/File/Sven Nackstrand) |
"The tree line has moved by up to 200 meters (656 feet) in some places.
Trees have not grown at such high levels for around 7,000 years," Leif
Kullman, a professor at Umeaa University's department of ecology and
environmental science, told AFP Tuesday.
The tree line represents a limit in mountainous, northern and southern latitudes beyond which trees do not grow.
"Recordings began in 1915 but the trend has intensified in the past 15 to 20 years," Kullman said.
Sweden's climate in the past 20 years was as mild as it had been some 7,000 years ago, he added.
While
some of the change could be explained by natural phenomena such as the
reduction in global volcanic activity -- allowing more sunlight to warm
the Earth -- the trend was clearly provoked for the most part by
man-made factors.
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Friday, January 12, 2007
Lloyd's boss demands action on climate change
Here's a link to the Lloyds report that goes with the announcement
http://www.lloyds.com/NR/rdonlyres/6498A184-F610-449F-9AA9-91C205622BC8/0/WhatNextforClimateChange.pdf
Thursday, January 04, 2007
Friday, December 22, 2006
Wednesday, December 06, 2006
Monday, November 27, 2006
Carbon emissions show sharp rise
BBC NEWS : Carbon emissions show sharp rise
Thursday, November 23, 2006
Science & Technology at Scientific American.com: Mysterious Stabilization of Atmospheric Methane May Buy Time in Race to Stop Global Warming
Scientific American.com: Mysterious Stabilization of Atmospheric Methane May Buy Time in Race to Stop Global Warming
Wednesday, November 22, 2006
Monday, November 20, 2006
2007 crucial in global warming battle: UK
2007 crucial in global warming battle: UK - Yahoo! News
Wednesday, November 15, 2006
Climate Change Is as Serious as WMD: Annan
Climate Change Is as Serious as WMD: Annan
Tuesday, November 14, 2006
WWF - Climate change has birds out on a limb
WWF - Climate change has birds out on a limb
Monday, November 13, 2006
Ice-melt isolates remote communities in Canada - Yahoo! News
Ice-melt isolates remote communities in Canada - Yahoo! News
Wednesday, November 08, 2006
Malaria surge in Kenyan highlands may be tied to global warming - Yahoo! News
Malaria surge in Kenyan highlands may be tied to global warming - Yahoo! News
Thursday, November 02, 2006
Scientists Say White House Muzzled Climate Research
"These investigations are critical because the Republicans in Congress have ignored this serious problem," Lautenberg said.
Scientists Say White House Muzzled Climate Research
Wednesday, November 01, 2006
White House shrugs off the Stern report
There's also doubt that using Al Gore as the point man will have much effect in DC.
Analysts Sceptical about Report's Impact in US - and Benefits of Using Al Gore
Tuesday, October 31, 2006
Comments on the Stern report
A Global Catastrophe of Our Own Making
A Global Catastrophe of Our Own Making
Monday, October 30, 2006
Gore to advise British on global warming
British Treasury chief Gordon Brown, who commissioned the report, said former Vice PresidentAl Gore, who has dedicated much time to warning of the effects of global warming, would advise the British government on climate change.
Gore to advise British on global warming - Yahoo! News
Gore to advise British on global warming
British Treasury chief Gordon Brown, who commissioned the report, said former Vice President Al Gore, who has dedicated much time to warning of the effects of global warming, would advise the British government on climate change.
Gore to advise British on global warming - Yahoo! News
Saturday, October 28, 2006
Climate Change Economic Warning
Tackle Climate Change or Face Deep Recession, World's Leaders Warned
Wednesday, October 25, 2006
Warming link to amphibian disease
BBC NEWS | Science/Nature | Warming link to amphibian disease
Tuesday, October 24, 2006
Bill Mc Kibben - Saving the Planet Will Require Community Effort
How Close to Catastrophe? Saving the Planet Will Require Community Effort
Global ecosystems 'face collapse'
BBC NEWS | Science/Nature | Global ecosystems 'face collapse'
Saturday, October 21, 2006
Friday, October 20, 2006
Climate Change 'Will Cause Refugee Crisis'
Climate Change 'Will Cause Refugee Crisis'
Update on Greenland ice sheet
Greenland ice sheet shrinking fast: NASA - Yahoo! News
Wednesday, October 18, 2006
UN to talk on climate adaptation
BBC NEWS | Science/Nature | UN to talk on climate adaptation
Monday, October 16, 2006
Antarctic ice collapse linked to greenhouse gases - Yahoo! News
Antarctic ice collapse linked to greenhouse gases - Yahoo! News
Saturday, October 14, 2006
Shell: Climate change is a business opportunity
Shell: Climate change is a business opportunity
Schwarzenegger takes green roadshow to New York - Yahoo! News
Schwarzenegger takes green roadshow to New York - Yahoo! News
U.S. West becoming warmer faster - Yahoo! News
Expert: U.S. West becoming warmer faster - Yahoo! News
Friday, October 13, 2006
Climate change inaction will cost trillions: study - Yahoo! News
Climate change inaction will cost trillions: study - Yahoo! News
UK government plans bill on climate change - Yahoo! News
UK government plans bill on climate change - Yahoo! News
Tuesday, October 10, 2006
Climate change may hurt Asian economies - Yahoo! News
Climate change may hurt Asian economies - Yahoo! News
Monday, October 09, 2006
Impact from the Deep - Scientific American
Science & Technology at Scientific American.com: Impact from the Deep -- [ EARTH SCIENCE ] -- Strangling heat and gases emanating from the earth and sea, not asteroids, most likely caused several ancient mass extinctions. Could the same killer-greenhouse
Thursday, October 05, 2006
Global Warming Will Alter Character of the Northeast
Global Warming Will Alter Character of the Northeast
The Century of Drought
The Century of Drought
Wednesday, October 04, 2006
Suppressed NOAA hurricane consensus statement
NOAA Fact Sheet: Atlantic Hurricanes and Climate
What has been Atlantic hurricane activity during the 20th Century?
-- Atlantic hurricane seasons since 1995 have been significantly more active, e.g. more hurricanes and more intense hurricanes, that the previous two decades (figure 1)
-- Earlier periods, such as from 1945 to 1970 (and perhaps earlier), were apparently as active as the most recent decade.
-- The past decade has seen increased U.S. landfalls, however periods of even higher landfalls occurred early in the century (figure 2)
-- Strong natural decadal variations, as well as changes in data quality, density, sources, and methodologies for estimating hurricane strengths, lie at the heart of arguments whether or not a global warming contribution to a trend in tropical cyclone intensities can be detected.
How have ocean temperatures varied?
-- Over the 20th Century, global ocean temperatures and sea surface temperatures in the main development region (MDR) for hurricanes in the tropical Atlantic, (and Gulf of Mexico) have warmed at similar rates, indicating a role for global warming in these regions. (Figure 3)
-- Anomalous MDR, tropical Atlantic temperatures were significantly warmer than the global average from about 1930 to 1970 and after 2000. This warming is attributed to the Atlantic Multi-decadal Oscillation (AMO)
What factors influence seasonal to multi-decadal hurricane activity
-- Hurricanes respond to a variety of environmental factors besides local ocean temperatures.
-- The tropical multi-decadal phenomenon and the El Nino/La Nina cycle are important factors in determining the conditions for seasonal to multi-decadal extremes in hurricane activity.
-- Research indicates that global warming can also increase hurricane intensities; there is less evidence for impacts on frequency.
How long will the current active period last?
-- Scientists disagree as to whether currently a sound basis exists for making projections on how long the current active period will last. The viewpoints are:
o Limited understanding of natural decadal variability, combined with its irregular temporal behavior, preclude definitive statements about how long the active period will last. (NOAA)
o One might expect ongoing high levels of hurricane activity and U.S. landfalls for the next decade and beyond since the previous active period (1945-1970) lasted at least 25 years. (NOAA)
o Because of global warming the active period could persist
Programs of improvements to data sets, diagnostic studies for improved understanding, and systematic numerical experimentation studies will help to reveal the underlying causes for the recent active period and to predict how long the period of increased activity will last. NOAA is actively engaged in each of these activities.
Key Problems NOAA is working on
-- Understanding the dynamics of the AMO, its links to the larger-scale tropical climate variability, and developing an ocean monitoring and decadal prediction capability
-- Improving the quality and scope of hurricane relevant data sets
-- Numerically simulating and ultimately understanding seasonal to decadal hurricane variability
-- Understanding whether or not and to what degree anthropogenic forcing is having an influence on hurricanes
-- Developing a predictive understanding of global climate variability and trends and the impacts of these on extreme events
-- Making improvements to short range hurricane track and intensity forecasts through improved models and development of additional capabilities for hurricanes.
NOAA Resources for Additional Information
-- NWS/NCEP/CPC intraseasonal to multi-season climate forecasts; seasonal hurricane forecasts; diagnostic studies of major climate anomalies; real time monitoring of climate.
-- NWS/NCEP/TPC/NHC issue daily and seasonal (in conjunction with CPC and HRD) operational hurricane forecasts; maintain and update the official Atlantic and Northeast Pacific hurricane databases from which observational climate studies are conducted
-- NESDIS/NCDC official archive for climate data sets; development of global tropical cyclone databases, analysis of historical frequency and strength of Atlantic Basin hurricanes to support engineering design and levee rebuilding in New Orleans, analyses of climate trends, monitoring and historical perspective on current seasons.
-- OAR/AOML/HRD & PHoD physical understanding of hurricane dynamics through use of research aircraft and field studies; improvements to hurricane track and intensity forecasts; monitoring of Atlantic ocean circulations; studies of Atlantic climate
-- OAR/GFDL studies of climate variability and change; development and use of the required climate models; development of models used for operational hurricane forecasts by NOAA and the NAVY; numerical studies of climate impacts on hurricanes and their decadal variability
-- OAR/ESRL diagnostic studies of climate variability and changes; impacts of climate on extreme events.
-- NOAA Climate Office intramural and extramural support for development of a predictive understanding of the climate system, the required observational capabilities, delivery of climate services.
Tuesday, October 03, 2006
Summit addresses climate change costs
BBC NEWS | Science/Nature | Climate costs top summit's agenda
Carl Wunsch, The Economist and the Gulf Stream
RealClimate » Carl Wunsch, The Economist and the Gulf Stream
Saturday, September 30, 2006
Science and action on climate change diverging
Science and action on climate change diverging: UK - Yahoo! News
Friday, September 29, 2006
Rare Mineral Further Implicates CO2 in Last Global Warming
Science & Technology at Scientific American.com: Rare Mineral Further Implicates CO2 in Last Global Warming
Tuesday, September 26, 2006
NASA GISS: Research News: NASA Study Finds World Warmth Edging Ancient Levels
NASA GISS: Research News: NASA Study Finds World Warmth Edging Ancient Levels
Earth may be at warmest point in 1 million years - Yahoo! News
Earth may be at warmest point in 1 million years - Yahoo! News
Monday, September 25, 2006
Global Warming Takes a Break - Yahoo! News
Global Warming Takes a Break - Yahoo! News
60 Years to Restore the Ozone Layer Over Antarctica
60 Years to Restore the Ozone Layer Over Antarctica
Mass Tourism and Climate Change
Mass Tourism and Climate Change Could Lead to Destruction of World's Wonders
Friday, September 22, 2006
Sorry about the gap
Wednesday, September 13, 2006
Study acquits sun of climate change, blames humans - Yahoo! News
Study acquits sun of climate change, blames humans - Yahoo! News
Thursday, September 07, 2006
Wednesday, September 06, 2006
Permafrost Methane release accelerating
Scientists see new global warming threat - Yahoo! News
Tuesday, September 05, 2006
Deep ice tells long climate story
BBC NEWS | Science/Nature | Deep ice tells long climate story
RealClimate The beginning of an IPCC response
RealClimate » Chinese whispers in Australia
Saturday, September 02, 2006
Climate panel lowers global warming forecast: report - Yahoo! News
Climate panel lowers global warming forecast: report - Yahoo! News
Global Warming Increases Gene Crossovers in Fruit Flies
Science & Technology at Scientific American.com: Global Warming Shows Up in Fly Genes
Thursday, August 31, 2006
Global Warming Spurs Ocean Methane Release
Scientific American.com: Global Warming Spurs Ocean Methane Release
Ocean plankton absorb less CO2
BBC NEWS | Science/Nature | Ocean plankton absorb less CO2
Study: Summer is Getting Longer - Yahoo! News
Study: Summer is Getting Longer - Yahoo! News
California takes lead in U.S. global warming fight - Yahoo! News
California takes lead in U.S. global warming fight - Yahoo! News
Wednesday, August 30, 2006
Monday, August 28, 2006
Disaster-prone China takes heed of global warming - Yahoo! News
Disaster-prone China takes heed of global warming - Yahoo! News
Sunday, August 27, 2006
Thursday, August 24, 2006
McKibben on Global Warming
Finally, Fired up over Global Warming
Wednesday, August 23, 2006
Insurance Industry faces climate change
Plugged in: Insurance companies grapple with global warming - Aug. 23, 2006
Wednesday, August 16, 2006
Simple arguments for why climate can be predicted
RealClimate » Short and simple arguments for why climate can be predicted
Tuesday, August 15, 2006
Saturday, August 12, 2006
Triple dose of morbidity
First, dying Aspens
Then the Pacific dead zone growing
And then mysterious die-offs of Salt Marsh vegetation
I'm not sure that they are all caused by globalwarming, though I suspect that it is at last a stressor on most systems.
Greenland's Ice Melting is a Fright
Greenland's Ice Cap is Melting at a Frighteningly Fast Rate
Saturday, August 05, 2006
The Canary Project
The Canary Project
The Climate Group
Website for this "independent, nonprofit organization dedicated to advancing business and government leadership on climate change. ... based in the UK, the USA and Australia." Features interviews with international business and government leaders, case studies about actions being taken by governmental and corporate actors "to minimize their carbon footprints," and suggestions for individuals for reducing emissions (with links to related sites). Also includes links to news stories, online publications, and more.
RealClimate » Amazonian drought
RealClimate » Amazonian drought
Friday, August 04, 2006
US congress body supports Climate Science findings
BBC NEWS | Science/Nature | Backing for 'hockey stick' graph
Scientists call for more alternative energy researc
BBC NEWS | Science/Nature | Top scientist makes climate plea
Saturday, July 29, 2006
California heat kills 25,000 cattle: official
BREITBART.COM - California heat kills 25,000 cattle: official
2003 Europen heatwave report
July 28, 2006: SETTING THE RECORD STRAIGHT: More than 52,000 Europeans Died from Heat in Summer 2003
Thursday, July 27, 2006
Limits of Nuclear Energy in warmer world
European Heat Wave Shows Limits of Nuclear Energy - Yahoo! News
Wednesday, July 26, 2006
Soya Crops Expansion halts for a while
Moratorium on New Soya Crops Wins Reprieve For Rainforest
Tuesday, July 25, 2006
FOXNews.com - Researchers Link Wildfires, Climate Change - Science News | Current Articles
FOXNews.com - Researchers Link Wildfires, Climate Change - Science News | Current Articles
Lovelock's book - The Revenge of Gaia
I'm back to hopeless. Lovelock's book is devastating, and his science is as solid as the less alarming, but less prone to overstatemant academic variety. The endless stream of bad news as told in this blog and elsewhere is daunting and depressing. I'm back to figuring how to get to Alaska and how to stay there. Get a job in the oil industry? Good birding for awhile, and severe seasonal bipolar roller-coaster. And wondering if it's even worth it.
An interesting aspect of the book is Lovelock's insistence that the only currently available time-buying technology is nuclear power generation. That doesn't sit well with an old activist, but his logic is simple: the disaster of rampant global warming is far worse than all the problems associated with nukes. I can see his point, but it's hard to swallow. And even that is a no guarantee solution. I'm uneasy about the proliferation of nuclear materials in an increasingly unstable and desperate world, witness the current eruption in the middle east, and the US encouragement and support of (nuclear armed) Israel.
Another strange glitch in the book is his opposition to wind power. He seems to believe that it's beside the point, though it is proving its effectiveness by leaps and bounds. Still, one gets the impression that his real objection is aesthetic, that he sees it ruining the countryside which he treasures, especially parts that haven't been taken over by industrial agriculture. In light of his perspective on nukes, the clear lesser-of-two-evils thinking there, it's a glaring inconsistency. I wonder how much Tony Blair's advocacy of a nuclear ramping up to combat carbon emissions stems from Lovelock's stance? I don't know how well they're acquainted, but Lovelock is one of the world's prominant public scientists.
I still haven't seen the Al Gore movie. Guess I'll have to cobble up a review of that too.
More detail on melting Greenland glaciers
In a recent paper in Science, Eric Rignot and Pannir Kanagaratnam present new satellite observations of the speed of glaciers of Greenland, and find that they are sliding towards the sea almost twice as fast as previously thought. Additionally, between 1996 and 2005, they detected a widespread glacier acceleration and consequently an increased rate of ice discharge from the Greenland ice sheet. However, previous papers have recently noted an increase in snow accumulation in the interior (i.e. Johanessen et al., 2005), so how do these different measurements fit into the larger picture of Greenland's net mass balance?
The measurements by Rignot & Kanagartnam were made with interferometers which measure the movement of the surface horizontally, and so is complimentary to the altimeter data published previously (which measures the absolute height of the ice). Overall, they found widespread increases in glacier speeds, and increases of about 30% in ice discharge rates. (Note that the satellite image shows that the glaciers in the east tend to slide far into the sea whereas on the western coast that happens less).
The higher velocity of the ice is thought to be related to higher temperatures causing increased melt-water which can penetrate to the base of the glacier and hence reduce the ground friction. However, this accelerated movement is not necessarily tied to an increased rate of melting of the Greenland ice, although it can be related. Surges of ice streams from the ice sheet can also occur due to increased accumulation at the head of the glacier. However, when the increased ice velocity is matched to a decreasing thickness that can be sign of net mass loss. These ideas are consistent with observations of surface melting which had a record extent in 2005, and has been increasing steadily (though with significant interannual variability) since 1993. Using the analysis of Hanna et al (2005) (based on the reanalysis datasets) for the surface mass balance, Rignot & Kanagartnam estimate that Greenland is on balance losing mass, and over the period of their study the ice sheet mass deficit (the amount of ice lost to the sea) has doubled increasing from 90 to 220 km3/year (an increase of 0.23 to 0.57 mm/yr sea level equivalent - SLE).
In the earlier Science paper, Johanessen et al. found increased snow accumulation on the top of the interior Greenland ice sheet between 1992 and 2003. Above 1500m a.s.l in much of the interior Greenland they estimated an increase of 6.4 ± 0.2 cm/year and below 1500m they observed a decreasing trend of -2.0 ± 0.9 cm/year. Hence, growth in the interior parts and a thinning of the ice nearer the edges. However, Johanessen et al. were not able to measure all of the coastal ranges. Indeed, the thinning of the margins and growth in the interior Greenland is an expected response to increased temperatures and more precipitation in a warmer climate. These results present no contradiction to the accelerated sliding near the coasts, but both will affect the ice/snow (fresh water) mass estimate. Whereas the finding of Rignot & Kanagaratnam suggests a larger sink of the frozen Greenland fresh water budget (the ice is dumped into the sea), the snow deposition in Greenland interiors is a source term (increases the amount of frozen fresh water). It does not matter for the general sea level in which form the water exists (liguid or solid/frozen) when it is discharged into the sea: The same mass of liquid water and immersed ice affect the water level equally (Archimede's principle).
A third relevant study is a recent paper in the Journal of Glaciology by Zwally et al. (2005) on the ice mass changes on Greenland and Antarctica. They use the same satellite obsevations (ERS 1 & 2) as Johanessen et al. and again find that the Greenland ice sheet is thinning at the margins (-42 ± 2 Gt/year = -46 ± 2 km3/year below the equilibrium-line altitude - ELA), but growing in the inland (+53 ± 2 Gt/year = 58 ± 2 km3/year). The mass estimates have been converted to volume estimates here, assuming the density of ice is 0.917 g/cm3 at 0°C, so that the mass of one Gt of ice is roughly equivalent to 1.1km3 ice*. This means that the Greenland ice has an overall mass gain by +11 ± 3 Gt/year (=10 ± 2.7 km3/year) which they estimated implied a -0.03 mm/year SLE over the period 1992-2002.
The critical point for Greenland is whether the increased rate of glacier motion more than compensates for the greater accumulation on the surface. While the broad picture of what is happening is consistent between these papers, the bottom-line value for Greenland's mass balance is different in all three cases. Looking just at the dynamical changes observed by Rignot & Kanagaratnam, there is an increased discharge of about 0.28 mm/year SLE from 1996 to 2005, well outside the range of error bars. This is substantially more than the opposing changes in accumulation estimated by Johannessen et al and Zwally et al, and is unlikely to have been included in their assessments. Thus, the probability is that Greenland has been losing ice in the last decade. We should be careful to point out though that this is only for one decade, and doesn't prove anything about the longer term. As many of the studies make clear, there is a significant degree of interannual variability (related to the North Atlantic Oscillation, or the response to the cooling associated with Mt. Pinatubo) such that discerning longer term trends is hard.
The largest contributions to sea level rise so far are estimated to have come from thermal expansion, with the melting of mountain glaciers and icecaps being of second order. Looking forward, the current (small) imbalance (whether positive or negative) of the Greenland ice sheet is not terribly important. What matters is if the melting were to increase significantly. Ongoing observations (most promisingly from the GRACE gravity measurements, Velicogna et al, 2005) will be useful in monitoring trends, but in order to have reasonable projections into the future, we would like to be able to rely on ice sheet models. Unfortunately, the physics of basal lubrication and the importance of ice dynamics highlighted in the Rignot & Kanagaratnam results are very poorly understood and not fully accounted for in current ice sheet models. Until those models include these effects, there is a danger that we may be under-appreciating the dynamic nature of the ice sheets.
References:
Hanna, E; Huybrechts, P; Janssens, I; Cappelen, J; Steffen, K; Stephens, A (2005) J. Geophys. Res.Vo. 110, D13108, doi:10.1029/2004JD005641
Johanessen, O.M; Khvorostovsky, K; Miles, M.W; Bobylev, L.P. (2005) ScienceVo. 310 no. 5750, pp 1013-1016
Ringnot, E; Kanagaratnam, P (2006) ScienceVo. 311 no. 5763, pp 986-990
Velicogna, I; Wahr, J; Hanna, E; Huybrechts, P. (2005) Geophys. Res. Lett.Vo. 32, L05501, doi:10.1029/2004GL021948
Zwally, H. Jay; Giovinetto, Mario B.; Li, Jun; Cornejo, Helen G.; Beckley, Matthew A.; Brenner, Anita C.; Saba, Jack L.; Yi, Donghui (2005), Journal of Glaciology, Volume 51, Number 175, December, pp. 509-527(19)
Monday, July 24, 2006
Ocean warming impacts on seabirds
Warmer Waters Disrupt Pacific Food Chain
Steep decline of one bird species for the second straight year has rekindled
scientists' fears that global warming could be undermining the coastal food
supply.
July 24, 2006 — By Marcus Wohlsen, Associated Press
FARALLON NATIONAL WILDLIFE REFUGE, Calif. — On these craggy, remote islands
west of San Francisco, the largest seabird colony in the contiguous United
States throbs with life. Seagulls swarm so thick that visitors must yell to be
heard above their cries. Pelicans glide.
But the steep decline of one bird species for the second straight year has
rekindled scientists' fears that global warming could be undermining the
coastal food supply, threatening not just the Farallones but entire marine
ecosystems.
Tiny Cassin's auklets live much of their lives on the open ocean. But in
spring, these gray-and-white relatives of the puffin venture to isolated Pacific
outposts like the Farallones to dig deep burrows and lay their eggs.
Adult auklets usually feed their chicks with krill, the minuscule
shrimp-like crustaceans that anchor the ocean's complex food web.
But not this year. Almost none of the 20,000 pairs of Cassin's auklets
nesting in the Farallones will raise a chick that lives more than a few days, a
repeat of last year's "unprecedented" breeding failure, according to Russ
Bradley, a seabird biologist with the Point Reyes Bird Observatory who monitors
the birds on the islands.
Scientists blame changes in West Coast climate patterns for a delay in the
seasonal upwelling of cold, nutrient-rich waters from the ocean's depths for
the second year in a row. Weak winds and faltering currents have left the Gulf
of the Farallones without krill, on which Cassin's auklets and a variety of
other seabirds, fish and mammals depend for food.
"The seas are warmer. And the number of krill being produced is lower," said
Bradley as he held a Cassin's auklet chick, the only one from a study of 400
nests he expected to survive.
"Normally we would have hundreds," he said.
The failure of last year's Pacific upwelling killed seabirds from California
to British Columbia. Scientists had hoped the change was just a natural
temperature fluctuation in what is known as the California Current.
But the return of higher ocean temperatures and scarce food resources this
year has scientists wondering whether last year's erratic weather was not a
fluke but the emergence of a troubling trend.
"How many years in a row do you see this before you start raising your
eyebrows?" said Frank Schwing, an oceanographer with the National Oceanic and
Atmospheric Administration in Pacific Grove.
Climatologists describe global warming as a worldwide rise in temperatures
caused by the buildup of carbon dioxide and other greenhouse gasses thought to
trap heat in the atmosphere. Predictions of global warming's effects include
rising sea levels, fiercer storms, more wildfires and warmer oceans.
Without long-term data, scientists have so far found it difficult to make
direct links between specific natural events and global warming.
But the Farallones present a special case. Researchers have kept Cassin's
auklet counts there every day since 1967. Never before have they seen such a
drop-off in numbers. That decline comes as California ocean temperatures hover
three to five degrees above average.
"One of the things that the climate models predict is that we're going to
have unpredictable weather, extreme weather, that the whole seasonal cycle of
events will not be what we expect," said Bill Peterson, a NOAA oceanographer
in Newport, Ore. "We aren't seeing normal patterns."
Perhaps nowhere is this ecological disruption felt more than here on the
Farallones, a 200-acre island chain often described as California's Galapagos.
The U.S. Fish and Wildlife Service keeps the national wildlife refuge closed
to visitors except for a small group of scientists and volunteers who live
there year-round.
The krill-dependent whales and salmon that inhabit the surrounding waters
have not appeared to suffer from the changes in food supply. But during a visit
to the islands this summer, scientists pointed to other species feeling the
consequences.
The absence of krill has led to a collapse of the juvenile rockfish
population. This is the main food source for young of the common murre, a bird that
resembles a flying penguin. Though the murre has made a dramatic comeback
recently, with about 200,000 adults nesting on the islands this year, nearly
three-quarters of murres breeding this year are not expected to raise chicks that
survive.
"At this point it's way too late in the season for the birds to initiate
another attempt at breeding," said Peter Warzybok, a Farallones-based biologist
with the Point Reyes Bird Observatory. "They'll just have to wait around for
next year and hope that it's better."
Significant drops in murre and Cassin's auklet numbers occurred during the
El Nino years of 1983 and 1992, when warmer Pacific waters near the equator
upset weather patterns worldwide.
A January conference of more than 40 climatologists, oceanographers, and
wildlife biologists issued a report describing last year's altered coastal
climate as El Nino-like conditions in a non-El Nino year. Some researchers have
given the new climate shift its own name: "El Coyote."
The report said a "ridge" of winter air blocking winds from the Gulf of
Alaska lingered more than two months longer than normal in 2005, which delayed
the upwelling until well past the birds' breeding seasons.
"It's not just a local effect," Schwing said. "It's related to global-scale
changes in atmospheric circulation."
But it could take researchers another decade to determine whether global
warming caused those changes. Some climatologists warn against drawing overly
broad conclusions from only two years of unusual weather.
Definitive results are "not around the corner," said Nick Bond, a research
meteorologist the University of Washington who has studied the upwelling's
failure.
"We just don't know how much the deck is stacked" by the effects of global
climate change, Bond said. "It's hard to tell from just a deal or two."
But whatever the cause, the ecological outcome if the trend continues is
already clear, according to scientists.
The Cassin's auklet is unlikely to adapt to the sudden loss of its main food
source. And other animals could follow, Schwing said.
In the worst case, he said, "we could see a great depression of the entire
ecosystem."
Source: Associated Press
Sunday, July 23, 2006
One Year to Save the Amazon
Dying Forest: One Year to Save the Amazon
Saturday, July 22, 2006
Friday, July 21, 2006
Thursday, July 20, 2006
Tuesday, July 18, 2006
Drought Threatens Amazon Basin
Drought Threatens Amazon Basin

