Global warming is speeding the release of carbon dioxide, a chief greenhouse gas, from underground peat in subarctic wetlands, Dutch research indicates.
The research suggests rising temperatures are adding to the magnitude and velocity of global warming, Free University plant ecologist Ellen Dorrepaal and colleagues write in the journal Nature.
Their research shows that raising temperatures about 1 degree Celsius accelerates total ecosystem respiration rates by as much as 60 percent, creating an effect that can last at least eight years.
This is greater than previously thought, highlighting the extreme sensitivity of northern peatland carbon reservoirs to global warming, the researchers say.
Peat is an accumulation of partially decayed plant matter that forms in wetlands, or peatlands. The peatlands, forming for 360 million years, cover about 2 percent of the earth's land mass and contain 550 gigatons (10 to the ninth power) of carbon.
The subarctic region is just south of the true arctic, covering much of Alaska, Canada, southern Greenland, the north of Scandinavia, Siberia, northern Mongolia and parts of China.
Wednesday, July 29, 2009
Past warming shows gaps in climate knowledge: study
A dramatic warming of the planet 55 million years ago cannot be solely explained by a surge in carbon dioxide levels, a study shows, highlighting gaps in scientists' understanding of impacts from rapid climate change.
During an event called the Palaeocene-Eocene Thermal Maximum, global temperatures rose between 5 and 9 degrees Celsius within several thousand years. The world at that time was already warmer than now with no surface ice.
"We now believe that the CO2 did not cause all the warming, that there were additional factors," said Richard Zeebe, an oceanographer with the University of Hawaii at Manoa.
"There may have been an initial trigger," he told Reuters on Wednesday from Hawaii. This could be a deep ocean warming that caused a catastrophic release of methane from hydrate deposits under the seabed.
Methane is a potent greenhouse gas but much of it is oxidised into CO2 when it is released from hydrate deposits.
Zeebe and his colleagues estimated the amount of CO2 released during the Palaeocene-Eocene event by studying sediment cores from seabeds around the globe. Their study is published in the latest issue of Nature Geoscience.
FUTURE WARMING
They estimated about 3 trillion tons of carbon (11 trillion tons of CO2) was released over several thousand years from the methane deposits, leading to a 70 percent rise in atmospheric CO2 levels from pre-event levels.
But Zeebe said this could only explain a 1 to 3.5 degree Celsius rise in temperatures, adding that a commonly accepted scientific range for a doubling of CO2 is between 1.5 and 4.5 degrees Celsius.
This meant other factors must have been at work to drive up temperatures between 5 and 9 degrees Celsius.
"If this additional warming which we do not really understand, was caused as a response to the CO2 warming, then there is a chance that also a future warming could be more intense than people anticipate right now," Zeebe said.
He said the study suggested there could be atmospheric or ocean processes as yet unknown or poorly understood that might have accelerated the warming. Possibilities could be changes in ocean currents, a much larger release of methane or even greater impacts from higher CO2 levels than currently thought.
At present, CO2 levels have already risen from 280 parts per million to nearly 390 ppm since the Industrial Revolution and could exceed a 70 percent increase during this century, a rate much faster than the Palaeocene-Eocene event, Zeebe said.
While this would cause initial effects, much worse could follow in the coming decades and centuries as the oceans, land and atmosphere tried to deal with the higher CO2 levels, he said.
"The carbon that we put into the atmosphere right now is going to stay there for a very long time. Much of it will stay there for tens of thousands of years."
During an event called the Palaeocene-Eocene Thermal Maximum, global temperatures rose between 5 and 9 degrees Celsius within several thousand years. The world at that time was already warmer than now with no surface ice.
"We now believe that the CO2 did not cause all the warming, that there were additional factors," said Richard Zeebe, an oceanographer with the University of Hawaii at Manoa.
"There may have been an initial trigger," he told Reuters on Wednesday from Hawaii. This could be a deep ocean warming that caused a catastrophic release of methane from hydrate deposits under the seabed.
Methane is a potent greenhouse gas but much of it is oxidised into CO2 when it is released from hydrate deposits.
Zeebe and his colleagues estimated the amount of CO2 released during the Palaeocene-Eocene event by studying sediment cores from seabeds around the globe. Their study is published in the latest issue of Nature Geoscience.
FUTURE WARMING
They estimated about 3 trillion tons of carbon (11 trillion tons of CO2) was released over several thousand years from the methane deposits, leading to a 70 percent rise in atmospheric CO2 levels from pre-event levels.
But Zeebe said this could only explain a 1 to 3.5 degree Celsius rise in temperatures, adding that a commonly accepted scientific range for a doubling of CO2 is between 1.5 and 4.5 degrees Celsius.
This meant other factors must have been at work to drive up temperatures between 5 and 9 degrees Celsius.
"If this additional warming which we do not really understand, was caused as a response to the CO2 warming, then there is a chance that also a future warming could be more intense than people anticipate right now," Zeebe said.
He said the study suggested there could be atmospheric or ocean processes as yet unknown or poorly understood that might have accelerated the warming. Possibilities could be changes in ocean currents, a much larger release of methane or even greater impacts from higher CO2 levels than currently thought.
At present, CO2 levels have already risen from 280 parts per million to nearly 390 ppm since the Industrial Revolution and could exceed a 70 percent increase during this century, a rate much faster than the Palaeocene-Eocene event, Zeebe said.
While this would cause initial effects, much worse could follow in the coming decades and centuries as the oceans, land and atmosphere tried to deal with the higher CO2 levels, he said.
"The carbon that we put into the atmosphere right now is going to stay there for a very long time. Much of it will stay there for tens of thousands of years."
Swine flu striking pregnant women hard: CDC study
Pregnant women infected with the new H1N1 swine flu have a much higher risk of severe illness and death and should receive prompt treatment with antiviral drugs, U.S. government researchers said on Wednesday.
While pregnant woman have always had a higher risk of severe disease from influenza in general, the new H1N1 virus is taking an exceptionally heavy toll, the researchers said.
"We do see a fourfold increase in hospitalization rates among ill pregnant women compared to the general population," Dr. Denise Jamieson of the U.S. Centers for Disease Control and Prevention said in a telephone interview.
"We're also seeing a relatively large proportion of deaths among pregnant women. We report 13 percent in the paper, but that is a very unstable number based on a small number of deaths reported," said Jamieson, whose study appears in the journal Lancet.
The study was based on the deaths of six pregnant women out of 45 deaths related to H1N1 reported to the CDC between April 15 and June 16.
All of the women were healthy prior to infection, and all developed pneumonia and needed to be put on a ventilator.
Jamieson said 302 deaths have been officially reported to the CDC from the new H1N1 virus.
"Among those, we have relatively complete information on 266 deaths. And of those, 15 have been among pregnant women, which is about 6 percent," Jamieson said.
Pregnant women make up about 1 percent of the U.S. population, she said, so pregnant women "are definitely over-represented in terms of the proportion of deaths."
Jamieson said pregnant women who suspect they have influenza should call their doctors promptly. The CDC recommends pregnant women with influenza get antiviral drugs as soon as possible, within the first 48 hours to be most effective.
Dr. Keiji Fukuda of the World Health Organization said WHO has not yet decided on its policy on the use of antivirals for pregnant women withH1N1.
"Given the overall situation in many countries where the supplies of antivirals can be limited at times, to concentrate them on treating people who are sick makes a lot of sense," he said on Britain's Sky television.
Fukuda said researchers are debating whether it is best to use antivirals to prevent disease or to treat sick people.
Both the CDC's Advisory Committee on Immunization Practices and the American College of Obstetricians and Gynecologists recommend that all pregnant women get a seasonal flu shot, but less than 14 percent do, according to the CDC.
The ACIP, which advises the CDC, was meeting on Wednesday to decide who should be first to get the new H1N1 vaccine. Pregnant women are expected to be at the head of the line.
amieson said pregnant women need to be aware of the risks if they become ill, but they do not need to change the way they live because of the new H1N1 flu.
"We do not have evidence that pregnant women have increased susceptibility or are more likely to acquire influenza," Jamieson said.
"It's just that when they have influenza they are at increased risk of having severe disease," she said.
While pregnant woman have always had a higher risk of severe disease from influenza in general, the new H1N1 virus is taking an exceptionally heavy toll, the researchers said.
"We do see a fourfold increase in hospitalization rates among ill pregnant women compared to the general population," Dr. Denise Jamieson of the U.S. Centers for Disease Control and Prevention said in a telephone interview.
"We're also seeing a relatively large proportion of deaths among pregnant women. We report 13 percent in the paper, but that is a very unstable number based on a small number of deaths reported," said Jamieson, whose study appears in the journal Lancet.
The study was based on the deaths of six pregnant women out of 45 deaths related to H1N1 reported to the CDC between April 15 and June 16.
All of the women were healthy prior to infection, and all developed pneumonia and needed to be put on a ventilator.
Jamieson said 302 deaths have been officially reported to the CDC from the new H1N1 virus.
"Among those, we have relatively complete information on 266 deaths. And of those, 15 have been among pregnant women, which is about 6 percent," Jamieson said.
Pregnant women make up about 1 percent of the U.S. population, she said, so pregnant women "are definitely over-represented in terms of the proportion of deaths."
Jamieson said pregnant women who suspect they have influenza should call their doctors promptly. The CDC recommends pregnant women with influenza get antiviral drugs as soon as possible, within the first 48 hours to be most effective.
Dr. Keiji Fukuda of the World Health Organization said WHO has not yet decided on its policy on the use of antivirals for pregnant women withH1N1.
"Given the overall situation in many countries where the supplies of antivirals can be limited at times, to concentrate them on treating people who are sick makes a lot of sense," he said on Britain's Sky television.
Fukuda said researchers are debating whether it is best to use antivirals to prevent disease or to treat sick people.
Both the CDC's Advisory Committee on Immunization Practices and the American College of Obstetricians and Gynecologists recommend that all pregnant women get a seasonal flu shot, but less than 14 percent do, according to the CDC.
The ACIP, which advises the CDC, was meeting on Wednesday to decide who should be first to get the new H1N1 vaccine. Pregnant women are expected to be at the head of the line.
amieson said pregnant women need to be aware of the risks if they become ill, but they do not need to change the way they live because of the new H1N1 flu.
"We do not have evidence that pregnant women have increased susceptibility or are more likely to acquire influenza," Jamieson said.
"It's just that when they have influenza they are at increased risk of having severe disease," she said.
House Democrats clinch healthcare deal
Democrats broke a logjam in President Barack Obama's drive to revamp the costly U.S. healthcare system on Wednesday when a group of party conservatives accepted a compromise that allowed an overhaul bill to advance in the House of Representatives.
The agreement with four conservative congressmen from Obama's Democratic Party sparked immediate grumbling from liberals, Republicans and others even as the breakthrough allowed a key House committee to take up the bill.
Obama, whose chief of staff, Rahm Emanuel, worked with members of Congress to craft the compromise, said he was grateful that lawmakers "are working so hard to find common ground."
"Those efforts are extraordinarily constructive in strengthening this legislation and bringing down its cost," Obama said.
Since taking office six months ago, Obama has made an overhaul of healthcare, which accounts for one-sixth of the U.S. economy, his top legislative priority.
He insists it is crucial to a broader economic recovery and has pushed lawmakers -- due to recess for a month soon -- to forge a deal quickly to rein in healthcare costs, improve care and cover most of the 46 million uninsured Americans.
Representative Mike Ross, a leader of the conservative Democrats known as the "Blue Dogs," told reporters the agreement, which followed lengthy negotiations with party leaders and the White House, would shave $100 billion off the bill's price tag of at least $1 trillion, making it more palatable to fiscal conservatives in both parties.
The Blue Dogs had put the brakes on the bill in the Energy and Commerce Committee, the last of three House committees to vote on it, over concerns about costs and other issues.
With the agreement, the bill was to move through that committee by Friday, even if House leaders later change it before the full House votes in September.
But Democratic Representative Eliot Engel said House leaders had left liberals on the panel with little choice but to vote for it as it stands or stall its progress.
"In a way, a number of us feel we've been held hostage," Engel said.
While the bill still includes a government-run insurance program, liberals said a requirement that Washington negotiate prices with doctors and hospitals -- putting the public plan on the same footing as private insurers -- would make coverage unaffordable for many.
The compromise would exempt 86 percent of small businesses from being required to contribute to health insurance for their workers. It would also allow states to set up insurance cooperatives alongside a national government health insurance plan.
Democrats on the Energy and Commerce Committee met in closed session to go over the details before a full panel meeting and votes on Thursday, and probably on Friday.
The agreement with four conservative congressmen from Obama's Democratic Party sparked immediate grumbling from liberals, Republicans and others even as the breakthrough allowed a key House committee to take up the bill.
Obama, whose chief of staff, Rahm Emanuel, worked with members of Congress to craft the compromise, said he was grateful that lawmakers "are working so hard to find common ground."
"Those efforts are extraordinarily constructive in strengthening this legislation and bringing down its cost," Obama said.
Since taking office six months ago, Obama has made an overhaul of healthcare, which accounts for one-sixth of the U.S. economy, his top legislative priority.
He insists it is crucial to a broader economic recovery and has pushed lawmakers -- due to recess for a month soon -- to forge a deal quickly to rein in healthcare costs, improve care and cover most of the 46 million uninsured Americans.
Representative Mike Ross, a leader of the conservative Democrats known as the "Blue Dogs," told reporters the agreement, which followed lengthy negotiations with party leaders and the White House, would shave $100 billion off the bill's price tag of at least $1 trillion, making it more palatable to fiscal conservatives in both parties.
The Blue Dogs had put the brakes on the bill in the Energy and Commerce Committee, the last of three House committees to vote on it, over concerns about costs and other issues.
With the agreement, the bill was to move through that committee by Friday, even if House leaders later change it before the full House votes in September.
But Democratic Representative Eliot Engel said House leaders had left liberals on the panel with little choice but to vote for it as it stands or stall its progress.
"In a way, a number of us feel we've been held hostage," Engel said.
While the bill still includes a government-run insurance program, liberals said a requirement that Washington negotiate prices with doctors and hospitals -- putting the public plan on the same footing as private insurers -- would make coverage unaffordable for many.
The compromise would exempt 86 percent of small businesses from being required to contribute to health insurance for their workers. It would also allow states to set up insurance cooperatives alongside a national government health insurance plan.
Democrats on the Energy and Commerce Committee met in closed session to go over the details before a full panel meeting and votes on Thursday, and probably on Friday.
Global warming to change life here
What will life be like in Lancaster County 40 years from now?
A climate more like Georgia or Maryland, depending on the severity of global warming, according to a new state-issued report on the long-term effects of climate change in Pennsylvania.
It will be rainier, especially in winter, though droughts also will be more common. There will be more summertime cloudbursts.
There will be less snow and more cold-rain events. You'll have to go out of state to use your snowmobiles, cross-country skis or ice-fishing poles.
Spring-thaw flooding on the lower Susquehanna may be less likely.
You'll spend more on air conditioning while saving on winter heating bills.
Fall colors here will be less showy as many maples will struggle to grow here. Instead, pine plantations are a possibility.
Sweet corn will grow faster. Potato and apple yields are likely to decline.
Dairy farmers here will have to become even more efficient to offset heat stress to cows, poorer yields of on-the-farm feed and possible challenges from milk producers in New Zealand and Australia.
Trout fishing may decline, while swimming, boating, golf and fishing for warm-water fish will likely increase.
"Certainly climate change is going to be happening, so preparing and adapting is something that needs to be done," Dr. James Shortle, a Penn State professor of agricultural and environmental economics and one of 10 lead researchers from Penn State who authored the report, said.
Among the be-prepared recommendations in the report: Communities should build more ballfields and bike paths.
The 350-page analysis, "Pennsylvania Climate Impact Assessment," was required by the Pennsylvania Climate Change Act passed by the Legislature in 2007. It was released by the state Department of Environmental Protection and is available online at www.depweb.state.pa.us. Fill in "Climate Change" in the keyword space.
The report states that global warming is already occurring and will accelerate, regardless of what the world does now.
However, the Pennsylvania scientists predict climate-change effects on two levels. One, if global-warming emissions continue to increase through the 21st century. Another scenario assumes the world reduces emissions and changes will be far more moderate.
Regardless of what action the world takes, "It is very likely that Pennsylvania will warm throughout the 21st century," the report states.
Following is a summary of key changes the state faces, according to the report.
ClimateBy the end of the century, the median temperature will increase by 7 degrees in the worst-case scenario and 3.5 degrees if emissions are decreased in the next 40 years.
The growing season will be extended by three weeks under lower emissions and by five weeks if global warming is not moderated.
Expect more extreme weather, whether storms or dry periods. "Flashier" storms may mean more runoff and erosion of soil and pollution into local streams and the Chesapeake Bay.
AgricultureEffects may be mixed for farmers.
Warmer temperatures and longer growing seasons may help yields of hay, corn and soybeans, but it may also raise yields elsewhere, increasing global production and pushing down prices for Pennsylvania farmers.
Warmer temperatures may continue to drive poultry and hog farming farther north to Pennsylvania.
State wineries may be able to grow higher-value European grapes for the first time.
"Among Pennsylvania farmers, dairy producers may experience the greatest challenges from climate change given their reliance on own-crop production, animal heat stress due to housing in the ambient environment, and impacts to forage quality that will affect productivity," the report said.
However, Don McNutt, director of the Lancaster County Conservation District, has faith in local farmers to adapt to any curves coming their way.
"Agriculture will step to the plate on that challenge, I think, really well. Never count the Lancaster County farmer out. They will think of a way to ingeniously step over the next hurdle. They've been doing it for more than 300 years."
McNutt predicted that continued genetic engineering will help farmers grow more heat-tolerant crops. Warmer feedlots could be cooled with geo-thermal systems, he said.
And the fact that local dairy farmers are within a day's drive of one-third of the nation's population puts them in better standing to weather fluctuating markets, McNutt thinks.
"We have a lot going for us."
The report said organic agriculture may get a boost with its moisture-retaining matter, but an increase in weeds may offset that advantage.
Forests"Climate change will likely cause many changes in Pennsylvania's forests," the report notes.
Northern hardwood trees such as the aspens and birches are expected to become extinct under worst-case scenarios. Southern species such as oaks and hickories will likely become more common.
The eight most common species currently in Pennsylvania — red and sugar maple, black birch, black cherry, beech, hemlock, white ash and northern red oak — are all projected to shrink, maybe even disappear.
Production of maple syrup in the state looks bleak.
Forest pests may increase, as well as invasive plants such as kudzu and Canada thistle.
Effects on the state's timbering industry are expected to be dramatic. The most valuable commercial tree, black cherry, is predicted to decline substantially, if not disappear.
Instead, loblolly and shortleaf pines, now in southern states, may be grown here, changing the makeup of trees grown for commercial sale.
Once new species are established, warmer temperatures, more precipitation and carbon dioxide fertilization may increase growth rates.
Waterways and fishDiversity of life in streams and wetlands will likely suffer from increased water temperatures and conditions that favor invasive species.
One big casualty: wild brook trout, the state fish, which survives only in pristine, cold water.
Human HealthMore intense summer heat will lead to more heat-related deaths, especially among those who don't have access to air conditioning. But people freezing to death will decline.
Smog and its harm to people with respiratory problems will increase.
Tourism, Outdoor RecreationThe report predicts that even with snow-making equipment, in the worst-case scenario ski resorts in the state may not survive.
The demand for fishing, boating and swimming is likely to increase, and the Fish and Boat Commission may want to increase access to streams and lakes and, perhaps, even consider building more reservoirs.
Deer may survive over winter at a higher rate, presenting new management challenges.
Golf, tennis and biking similarly will see upticks.
"Local communities should plan for this increase in demand for sports fields, bicycle paths, etc.," the report notes
A climate more like Georgia or Maryland, depending on the severity of global warming, according to a new state-issued report on the long-term effects of climate change in Pennsylvania.
It will be rainier, especially in winter, though droughts also will be more common. There will be more summertime cloudbursts.
There will be less snow and more cold-rain events. You'll have to go out of state to use your snowmobiles, cross-country skis or ice-fishing poles.
Spring-thaw flooding on the lower Susquehanna may be less likely.
You'll spend more on air conditioning while saving on winter heating bills.
Fall colors here will be less showy as many maples will struggle to grow here. Instead, pine plantations are a possibility.
Sweet corn will grow faster. Potato and apple yields are likely to decline.
Dairy farmers here will have to become even more efficient to offset heat stress to cows, poorer yields of on-the-farm feed and possible challenges from milk producers in New Zealand and Australia.
Trout fishing may decline, while swimming, boating, golf and fishing for warm-water fish will likely increase.
"Certainly climate change is going to be happening, so preparing and adapting is something that needs to be done," Dr. James Shortle, a Penn State professor of agricultural and environmental economics and one of 10 lead researchers from Penn State who authored the report, said.
Among the be-prepared recommendations in the report: Communities should build more ballfields and bike paths.
The 350-page analysis, "Pennsylvania Climate Impact Assessment," was required by the Pennsylvania Climate Change Act passed by the Legislature in 2007. It was released by the state Department of Environmental Protection and is available online at www.depweb.state.pa.us. Fill in "Climate Change" in the keyword space.
The report states that global warming is already occurring and will accelerate, regardless of what the world does now.
However, the Pennsylvania scientists predict climate-change effects on two levels. One, if global-warming emissions continue to increase through the 21st century. Another scenario assumes the world reduces emissions and changes will be far more moderate.
Regardless of what action the world takes, "It is very likely that Pennsylvania will warm throughout the 21st century," the report states.
Following is a summary of key changes the state faces, according to the report.
ClimateBy the end of the century, the median temperature will increase by 7 degrees in the worst-case scenario and 3.5 degrees if emissions are decreased in the next 40 years.
The growing season will be extended by three weeks under lower emissions and by five weeks if global warming is not moderated.
Expect more extreme weather, whether storms or dry periods. "Flashier" storms may mean more runoff and erosion of soil and pollution into local streams and the Chesapeake Bay.
AgricultureEffects may be mixed for farmers.
Warmer temperatures and longer growing seasons may help yields of hay, corn and soybeans, but it may also raise yields elsewhere, increasing global production and pushing down prices for Pennsylvania farmers.
Warmer temperatures may continue to drive poultry and hog farming farther north to Pennsylvania.
State wineries may be able to grow higher-value European grapes for the first time.
"Among Pennsylvania farmers, dairy producers may experience the greatest challenges from climate change given their reliance on own-crop production, animal heat stress due to housing in the ambient environment, and impacts to forage quality that will affect productivity," the report said.
However, Don McNutt, director of the Lancaster County Conservation District, has faith in local farmers to adapt to any curves coming their way.
"Agriculture will step to the plate on that challenge, I think, really well. Never count the Lancaster County farmer out. They will think of a way to ingeniously step over the next hurdle. They've been doing it for more than 300 years."
McNutt predicted that continued genetic engineering will help farmers grow more heat-tolerant crops. Warmer feedlots could be cooled with geo-thermal systems, he said.
And the fact that local dairy farmers are within a day's drive of one-third of the nation's population puts them in better standing to weather fluctuating markets, McNutt thinks.
"We have a lot going for us."
The report said organic agriculture may get a boost with its moisture-retaining matter, but an increase in weeds may offset that advantage.
Forests"Climate change will likely cause many changes in Pennsylvania's forests," the report notes.
Northern hardwood trees such as the aspens and birches are expected to become extinct under worst-case scenarios. Southern species such as oaks and hickories will likely become more common.
The eight most common species currently in Pennsylvania — red and sugar maple, black birch, black cherry, beech, hemlock, white ash and northern red oak — are all projected to shrink, maybe even disappear.
Production of maple syrup in the state looks bleak.
Forest pests may increase, as well as invasive plants such as kudzu and Canada thistle.
Effects on the state's timbering industry are expected to be dramatic. The most valuable commercial tree, black cherry, is predicted to decline substantially, if not disappear.
Instead, loblolly and shortleaf pines, now in southern states, may be grown here, changing the makeup of trees grown for commercial sale.
Once new species are established, warmer temperatures, more precipitation and carbon dioxide fertilization may increase growth rates.
Waterways and fishDiversity of life in streams and wetlands will likely suffer from increased water temperatures and conditions that favor invasive species.
One big casualty: wild brook trout, the state fish, which survives only in pristine, cold water.
Human HealthMore intense summer heat will lead to more heat-related deaths, especially among those who don't have access to air conditioning. But people freezing to death will decline.
Smog and its harm to people with respiratory problems will increase.
Tourism, Outdoor RecreationThe report predicts that even with snow-making equipment, in the worst-case scenario ski resorts in the state may not survive.
The demand for fishing, boating and swimming is likely to increase, and the Fish and Boat Commission may want to increase access to streams and lakes and, perhaps, even consider building more reservoirs.
Deer may survive over winter at a higher rate, presenting new management challenges.
Golf, tennis and biking similarly will see upticks.
"Local communities should plan for this increase in demand for sports fields, bicycle paths, etc.," the report notes
Global warming played a role in Incas' rise, report says
400-year warm spell in South America fueled the Incas' rise, British archaeologists reported Monday, helping them build the largest
several-degree increase in temperature allowed the Incas to move higher into the Andes mountains, opening up new farmland and providing a water source through the gradual melting of glaciers at the top of those mountains, paleoecologist Alex Chepstow-Lusty of the French Institute of Andean Studies in Lima reported online Monday in the journal Climate of the Past."They were highly organized and they had a sophisticated [governance], but it wouldn't have counted a jot without being underpinned by the warming of the climate," he said in a telephone interview.Other experts were cautious about his interpretation. "The premise that the Incan expansion was driven by climate change is quite revolutionary," said archaeologist Mark Bush of the Florida Institute of Technology in Melbourne.
Confirming it will require a great deal more work for paleoecologists and archaeologists alike.The new research is important because "data on Andean climate during this time period are scant," said archaeologist Warren Church of Columbus State University in Georgia, who works in Peru. "However, it is important to remember that climates do not make empires. People do."Chepstow-Lusty, geographer Mick Frogley of the University of Sussex and their colleagues have been studying a 26-foot-long core of mud drilled from the sacred Lake Marcacocha in the Patacancha Valley of Peru, near Cuzco. Seeds, pollen, charcoal bits and other debris from successive layers in the core paint a picture of climate and agriculture in the region for 4,000 years.Analysis of the core showed that a major drought began in the region around the year 880 and lasted for at least 100 years.That drought, Chepstow-Lusty speculated, may have been the cause of the demise of the Wari empire, which lasted from 550 to 1000. The region was also colder than normal for the 3,000 years before 1000.Beginning about 1150, the climate began warming and eventually got "several degrees centigrade" warmer, Chepstow-Lusty said. That had the net effect of extending arable regions to an altitude about 300 yards higher in the mountains, he suggested, vastly extending the area that could be cultivated. It also might have caused the Peruvian glaciers to melt slowly, providing water that the Incas captured with large irrigation systems and agricultural terraces.The major evidence for the warming, Chepstow-Lusty said, was the appearance of alder-like trees that hadn't been seen in the region before, as well as increased insect activity. The trees, which normally grow in warmer climates, grow well in poor soil and fertilize it by converting nitrogen from the atmosphere into a usable form.The increased cultivation would have led to large surpluses of maize and potatoes, the researchers speculated, freeing the Incas to undertake other activities, including building monuments and roads and creating a large standing army that allowed them to conquer nearby peoples.By the time the Spanish arrived in 1533, the Incas controlled an area that stretched from what is now the Colombian border with Ecuador to the middle of Chile, with more than 8 million inhabitants. When the Spanish arrived, they noted that the Incas had enough food in warehouses to last for 10 years.The Incan empire ended after the arrival of the Spanish, who inadvertently brought diseases that devastated the population, allowing the invaders to conquer the survivors and push them to the highest altitudes, where they are still marginalized economically.The story has a powerful moral for today, Chepstow-Lusty said. Peru is one of the countries most threatened by global warming, and the glaciers that provide much of the water for the capital, Lima, are rapidly melting and are expected to be gone in 20 years. The terraces that previously trapped water for agriculture have fallen into disuse, and the predominant tree in the region is the eucalyptus, which saps what water remains in the soil and deposits resins that poison other plant life.Chepstow-Lusty called for removal of the eucalyptus tree and a massive reforestation effort with alder or similar trees to replenish the soil, as well as repair of the derelict irrigation systems so they can once more support agriculture.But Church, who also works in Peru, cautioned that without more research, such an approach could be "premature and risky."
several-degree increase in temperature allowed the Incas to move higher into the Andes mountains, opening up new farmland and providing a water source through the gradual melting of glaciers at the top of those mountains, paleoecologist Alex Chepstow-Lusty of the French Institute of Andean Studies in Lima reported online Monday in the journal Climate of the Past."They were highly organized and they had a sophisticated [governance], but it wouldn't have counted a jot without being underpinned by the warming of the climate," he said in a telephone interview.Other experts were cautious about his interpretation. "The premise that the Incan expansion was driven by climate change is quite revolutionary," said archaeologist Mark Bush of the Florida Institute of Technology in Melbourne.
Confirming it will require a great deal more work for paleoecologists and archaeologists alike.The new research is important because "data on Andean climate during this time period are scant," said archaeologist Warren Church of Columbus State University in Georgia, who works in Peru. "However, it is important to remember that climates do not make empires. People do."Chepstow-Lusty, geographer Mick Frogley of the University of Sussex and their colleagues have been studying a 26-foot-long core of mud drilled from the sacred Lake Marcacocha in the Patacancha Valley of Peru, near Cuzco. Seeds, pollen, charcoal bits and other debris from successive layers in the core paint a picture of climate and agriculture in the region for 4,000 years.Analysis of the core showed that a major drought began in the region around the year 880 and lasted for at least 100 years.That drought, Chepstow-Lusty speculated, may have been the cause of the demise of the Wari empire, which lasted from 550 to 1000. The region was also colder than normal for the 3,000 years before 1000.Beginning about 1150, the climate began warming and eventually got "several degrees centigrade" warmer, Chepstow-Lusty said. That had the net effect of extending arable regions to an altitude about 300 yards higher in the mountains, he suggested, vastly extending the area that could be cultivated. It also might have caused the Peruvian glaciers to melt slowly, providing water that the Incas captured with large irrigation systems and agricultural terraces.The major evidence for the warming, Chepstow-Lusty said, was the appearance of alder-like trees that hadn't been seen in the region before, as well as increased insect activity. The trees, which normally grow in warmer climates, grow well in poor soil and fertilize it by converting nitrogen from the atmosphere into a usable form.The increased cultivation would have led to large surpluses of maize and potatoes, the researchers speculated, freeing the Incas to undertake other activities, including building monuments and roads and creating a large standing army that allowed them to conquer nearby peoples.By the time the Spanish arrived in 1533, the Incas controlled an area that stretched from what is now the Colombian border with Ecuador to the middle of Chile, with more than 8 million inhabitants. When the Spanish arrived, they noted that the Incas had enough food in warehouses to last for 10 years.The Incan empire ended after the arrival of the Spanish, who inadvertently brought diseases that devastated the population, allowing the invaders to conquer the survivors and push them to the highest altitudes, where they are still marginalized economically.The story has a powerful moral for today, Chepstow-Lusty said. Peru is one of the countries most threatened by global warming, and the glaciers that provide much of the water for the capital, Lima, are rapidly melting and are expected to be gone in 20 years. The terraces that previously trapped water for agriculture have fallen into disuse, and the predominant tree in the region is the eucalyptus, which saps what water remains in the soil and deposits resins that poison other plant life.Chepstow-Lusty called for removal of the eucalyptus tree and a massive reforestation effort with alder or similar trees to replenish the soil, as well as repair of the derelict irrigation systems so they can once more support agriculture.But Church, who also works in Peru, cautioned that without more research, such an approach could be "premature and risky."
New Blue Light Nanocrystals Could Help Mitigate Global Warming
Berkeley Lab researchers have produced non-toxic magnesium oxide nanocrystals that efficiently emit blue light and could also play a role in long-term storage of carbon dioxide, a potential means of tempering the effects of global warming.
In its bulk form, magnesium oxide is a cheap, white mineral used in applications ranging from insulating cables and crucibles to preventing sweaty-palmed rock climbers from losing their grip. Using an organometallic chemical synthesis route, scientists at the Molecular Foundry have created nanocrystals of magnesium oxide whose size can be adjusted within just a few nanometers. And unlike their bulk counterpart, the nanocrystals glow blue when exposed to ultraviolet light.
Current routes for generating these alkaline earth metal oxide nanocrystals require processing at high temperatures, which causes uncontrolled growth or fusing of particles to one another-not a desirable outcome when the properties you seek are size-dependent. On the other hand, vapor phase techniques, which provide size precision, are time and cost intensive, and leave the nanocrystals attached to a substrate.
"We've discovered a fundamentally new, unconventional mechanism for nicely controlling the size of these nanocrystals, and realized we had an intriguing and surprising candidate for optical applications," said Delia Milliron, Facility Director of the Inorganic Nanostructures Facility at Berkeley Lab's nanoscience research center, the Molecular Foundry. "This efficient, bright blue luminescence could be an inexpensive, attractive alternative in applications such as bio-imaging or solid-state lighting."
Unlike conventional incandescent or fluorescent bulbs, solid-state lighting makes use of light-emitting semiconductor materials-in general, red, green and blue emitting materials are combined to create white light. However, efficient blue light emitters are difficult to produce, suggesting these magnesium oxide nanocrystals could be a bright candidate for lighting that consumes less energy and has a longer lifespan.
These minute materials do more than glow, however. Along with their promising optical behavior, these magnesium oxide nanocrystals will be a subject of study in an entirely different field of research: Berkeley Labs' Energy Frontier Research Center (EFRC) for Nanoscale Control of Geologic CO2, designed to "establish the scientific foundations for the geological storage of carbon dioxide."
Experts say carbon dioxide capture and storage will be vital to achieving significant cuts in greenhouse gas emissions, but the success of this technology hinges on sealing geochemical reservoirs deep below the earth's surface without allowing gases or fluids to escape. If properly stored, the captured carbon dioxide pumped underground forms carbonate minerals with the surrounding rock by reacting with nanoparticles of magnesium oxide and other mineral oxides.
"These nanocrystals will serve as a test system for modeling the kinetics of dissolution and mineralization in a simulated fluid-rock reservoir, allowing us to probe a key pathway in carbon dioxide sequestration," said Jeff Urban, a staff scientist in the Inorganic Nanostructures Facility at the Molecular Foundry who is also a member of the EFRC research team. "The geological minerals that fix magnesium into a stable carbonate are compositionally complex, but our nanocrystals will provide a simple model to mimic this intricate process."
Hoi Ri Moon, a post-doctoral researcher at the Foundry working with Milliron and Urban, noted her team's direct synthesis method could also be helpful for already-established purposes. "As a user facility that provides support to nanoscience researchers around the world, we would like to pursue studies with other scientists who could use our nanocrystals as ‘feedstock' for catalysis, another application for which magnesium oxide thin films are commonly used," said Moon.
"
In its bulk form, magnesium oxide is a cheap, white mineral used in applications ranging from insulating cables and crucibles to preventing sweaty-palmed rock climbers from losing their grip. Using an organometallic chemical synthesis route, scientists at the Molecular Foundry have created nanocrystals of magnesium oxide whose size can be adjusted within just a few nanometers. And unlike their bulk counterpart, the nanocrystals glow blue when exposed to ultraviolet light.
Current routes for generating these alkaline earth metal oxide nanocrystals require processing at high temperatures, which causes uncontrolled growth or fusing of particles to one another-not a desirable outcome when the properties you seek are size-dependent. On the other hand, vapor phase techniques, which provide size precision, are time and cost intensive, and leave the nanocrystals attached to a substrate.
"We've discovered a fundamentally new, unconventional mechanism for nicely controlling the size of these nanocrystals, and realized we had an intriguing and surprising candidate for optical applications," said Delia Milliron, Facility Director of the Inorganic Nanostructures Facility at Berkeley Lab's nanoscience research center, the Molecular Foundry. "This efficient, bright blue luminescence could be an inexpensive, attractive alternative in applications such as bio-imaging or solid-state lighting."
Unlike conventional incandescent or fluorescent bulbs, solid-state lighting makes use of light-emitting semiconductor materials-in general, red, green and blue emitting materials are combined to create white light. However, efficient blue light emitters are difficult to produce, suggesting these magnesium oxide nanocrystals could be a bright candidate for lighting that consumes less energy and has a longer lifespan.
These minute materials do more than glow, however. Along with their promising optical behavior, these magnesium oxide nanocrystals will be a subject of study in an entirely different field of research: Berkeley Labs' Energy Frontier Research Center (EFRC) for Nanoscale Control of Geologic CO2, designed to "establish the scientific foundations for the geological storage of carbon dioxide."
Experts say carbon dioxide capture and storage will be vital to achieving significant cuts in greenhouse gas emissions, but the success of this technology hinges on sealing geochemical reservoirs deep below the earth's surface without allowing gases or fluids to escape. If properly stored, the captured carbon dioxide pumped underground forms carbonate minerals with the surrounding rock by reacting with nanoparticles of magnesium oxide and other mineral oxides.
"These nanocrystals will serve as a test system for modeling the kinetics of dissolution and mineralization in a simulated fluid-rock reservoir, allowing us to probe a key pathway in carbon dioxide sequestration," said Jeff Urban, a staff scientist in the Inorganic Nanostructures Facility at the Molecular Foundry who is also a member of the EFRC research team. "The geological minerals that fix magnesium into a stable carbonate are compositionally complex, but our nanocrystals will provide a simple model to mimic this intricate process."
Hoi Ri Moon, a post-doctoral researcher at the Foundry working with Milliron and Urban, noted her team's direct synthesis method could also be helpful for already-established purposes. "As a user facility that provides support to nanoscience researchers around the world, we would like to pursue studies with other scientists who could use our nanocrystals as ‘feedstock' for catalysis, another application for which magnesium oxide thin films are commonly used," said Moon.
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