More heat wave news, it's not just people.
BREITBART.COM - California heat kills 25,000 cattle: official
Saturday, July 29, 2006
2003 Europen heatwave report
Heat waves are serious business, and more are expected.
July 28, 2006: SETTING THE RECORD STRAIGHT: More than 52,000 Europeans Died from Heat in Summer 2003
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
There are several ironic twists in this story. Hotter weather means hotter reactors to cover cooling energy demands, but the reactrs have to shed their heat to the environment, usually to rivers or cooling lakes, and those may be damaged when the design criteria are over-ridden in a heat wave emergency.
European Heat Wave Shows Limits of Nuclear Energy - Yahoo! News
European Heat Wave Shows Limits of Nuclear Energy - Yahoo! News
Wednesday, July 26, 2006
Soya Crops Expansion halts for a while
One of the contributors to the rainforest problems in the Amazon ha ben a rapid expansion on soya farming, causing more deforestation than logging and grazing. This is some kind of reprieve, but may be partially a reaction to the drought already in progress, caused most likely partially by soya expansion. Loss of forest is interrupting the Amazon's ability to water itself by its own transpiration and subsequent cloud formation.
Moratorium on New Soya Crops Wins Reprieve For Rainforest
Moratorium on New Soya Crops Wins Reprieve For Rainforest
Tuesday, July 25, 2006
FOXNews.com - Researchers Link Wildfires, Climate Change - Science News | Current Articles
I picked this up off another blog. Pretty amazing that the hired guns of the oil companies (and maybe their subsidiaries in congress) are getting the message.
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
It was reading the reviews and some qotes from this book, now available in the US, (and even at my local library after I asked them to get a copy), that got me started on this blog. I felt dismal and hopeless, obvious if you read the first posts. Then I got lost in details, and read another book in the Meantime, "the Weather Makers", by Flannery, which didn't have so dismala take on the situation. Hope crept back. The alarm was more gradualist, time wasn't so critical, final scenarios from political incompetence weren't so drastic. Almost soothing.
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.
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
From Real Climate (I didn't note the date)
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)
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
This came in on one of my birding Listservs
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
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
This is seriously bad news, a great carbon sink turns into a great carbon source.
Dying Forest: 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
Truly alarming, a major dieback in the amazon is one of the tipping points for catastrophic global warming, since that forest is usually a carbon sink that removes CO2 from the atmosphere, but if the forest dies, it will release huge amonts instead.
Drought Threatens Amazon Basin
Drought Threatens Amazon Basin
Thursday, July 13, 2006
Saturday, July 08, 2006
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