For centuries Hindus have revered the sun god, Surya, as a source of health and prosperity, building lavish temples and holding festivals in his honour across a country with more than 300 days of sunshine a year.
Now India is putting its faith in the sun in a more literal sense by revealing what experts describe as the world’s most ambitious plan to develop solar energy over the next three or four decades.
Manmohan Singh, the Prime Minister, will chair a meeting today to decide whether to approve a National Solar Mission designed to curb India’s carbon emissions and ease its crippling power shortages. It proposes boosting India’s solar power generation capacity from almost zero to 20 gigawatts (20 billion watts) by 2020, 100GW by 2030 and 200GW by 2050, according to a draft seen by The Times. The entire world can generate about 14GW of solar power today.
India’s plan also proposes reducing the price of solar power to the same level as that from fossil fuels by 2020, according to the draft, dated April 29. Solar power in India currently costs about 15 rupees (20p) per kWh, compared with an average 3.5 rupees per kWh for electricity from the national grid, which is largely produced by coal-fired thermal power plants.
Other targets include forcing all government buildings to have solar panels by 2012 and developing micro-financing to encourage 20 million households to install solar lighting by 2020. The plan also outlines a system — similar to Germany’s — of paying households for any surplus power from solar panels fed back into the grid.
To achieve these and other goals, the mission proposes that the Government invest 920 billion rupees (£11.5 billion) in developing, manufacturing and installing solar technology over the next 30 years.
The mission is primarily designed to improve India’s energy security as it has abundant supplies of coal — the dirtiest of the fossil fuels — but has to import 70 per cent of its crude oil and half its natural gas. It is also meant to ease a chronic power shortage that has left 400 million Indians without electricity, causes daily blackouts in cities, and represents one of the biggest obstacles to economic growth.
India now has the capacity to produce 150GW — less than a fifth of China’s — and demand outstripped supply by 9.5 per cent between 2008-09, and by 13.8 per cent during peak hours, according to the Power Ministry. Indian officials also hope that the mission will help to ease the pressure from Western governments at international talks for a new UN climate pact in December.
Environmental campaigners have welcomed the plan, saying that solar energy is India’s most realistic alternative power source, as it does not have the space for large wind plants. Siddharth Pathak, chief climate change campaigner for Greenpeace in India, said: “India’s putting a very strong argument in front of developed countries that it has huge potential for renewable energy.” However, some government officials remain sceptical about risking so much money on new technology, rather than spending it on providing all Indians with electricity from conventional sources
Sunday, August 2, 2009
Bubbles of warming, beneath the ice
Four miles south of the Arctic Circle, the morning sky is streaked with apricot. Frozen rivers split the tundra of the Seward Peninsula, coiling into vast lakes. And on a silent, wind-whipped pond, a lone figure, sweating and panting, shovels snow off the ice.
The young woman with curly reddish hair stops, scribbles data, snaps a photo, grabs a heavy metal pick and stabs at white orbs in the thick black ice.
"Every time I see bubbles, I have the same feeling," says Katey Walter, a University of Alaska researcher. "They are amazing and beautiful."
Beautiful, yes. But ominous. When her pick breaks through the surface, the orbs burst with a low gurgle, spewing methane, a potent greenhouse gas that could accelerate the pace of climate change across the globe.
International experts are alarmed. "Methane release due to thawing permafrost in the Arctic is a global warming wild card," warned a report by the United Nations Environment Program last year. Large amounts entering the atmosphere, it concluded, could lead to "abrupt changes in the climate that would likely be irreversible."
Methane (CH4) has at least 20 times the heat-trapping effect of an equivalent amount of carbon dioxide (CO2). As warmer air thaws Arctic soils, as much as 55 billion tons of methane could be released from beneath Siberian lakes alone, according to Walter’s research. That would amount to 10 times the amount currently in the atmosphere.
At 32, Walter, an aquatic ecologist, is a rising star among the thousands of scientists who are struggling to map, measure and predict climate change. Parts of her doctoral dissertation on Siberian lakes were published in three prestigious journals in 2007: Science, Nature and Philosophical Transactions of the Royal Society.
According to one of her studies, methane emissions from Arctic lakes were a major contributor to a period of global warming more than 11,000 years ago.
"It happened on a large scale in the past, and it could happen on a large scale in the future," says Walter, who refers to potential methane emissions as "a time bomb."
Methane levels in the atmosphere have tripled since preindustrial times. Human activities, including rice cultivation, cattle raising and coal mining, account for about 70% of releases, according to recent studies. Natural sources, like tropical wetlands and termites, make up the rest. But those estimates had not incorporated the bubbles Walter was probing on an autumn morning on the Seward Peninsula.
That gurgling gas could change the entire model for predicting global warming. And lakes are not the only methane source: Newly discovered seeps -- places where methane leaks to the surface -- from the shallow waters of Siberia's vast continental shelf are also likely to upset previous assumptions.
Walter's work "has gotten a lot of attention," said John E. Walsh, chief scientist of the International Arctic Research Center in Fairbanks. "She found direct evidence of methane releases in high-latitude lakes. That was not fully realized before."
In a field where the science often seems opaque, Walter's research has a flashy side. She enjoys igniting methane seeps with a cigarette lighter, leaping away as the gas flares as high as 20 feet.
"It's fun," she says. "And it is informative."
Videos of the stunts have swept through the Internet, rare visual evidence of possible danger ahead. At a recent Senate hearing, Al Gore played a clip of her lighting a methane seep. The BBC, the Discovery Channel and the History Channel have featured her in documentaries.
But the complex science of Arctic methane is only beginning to be understood. In the desolate wilderness of the Bering Land Bridge National Preserve, a sense of urgency is palpable among Walter and three fellow researchers, hunkered down in neon-orange tents.
An occasional helicopter ferries supplies from Nome, the closest town, soaring over scattered herds of caribou. A red fox scampers through the brush. Across a snowfield, bear tracks recede into the distance, a reminder that field science isn't for sissies.
"Can you shoot a gun?" Walter asks a visitor, as she heads out to one of 20 lakes she is surveying. When the answer is noncommittal, she hands over bear spray and instructs: "Don't use it until the bear is right up close, facing you."
Nowhere is the evidence of a heating planet more dramatic than in the polar regions. Over the last 50 years, the Arctic has warmed twice as fast as the rest of the globe. Last summer, for the first time in recorded history, the North Pole could be circumnavigated. Ice sheets on Greenland and West Antarctica are melting rapidly. Polar bears and emperor penguins are threatened with extinction.
Even as glaciers and sea ice have captured the most headlines, growing concern is now focused on the transformation of permafrost, soils that are frozen year-round
Today, 20% of Earth's land surface is locked up in a deep freeze. But scientists predict that air temperature in the Arctic is likely to rise as much as 6 degrees Celsius, or 10.8 degrees Fahrenheit, by the end of the century. That is expected to boost the emission of carbon compounds from soils.
The upper 3 meters -- about 10 feet -- of permafrost stores 1.9 trillion tons of carbon, more than double the amount in the atmosphere today, according to a recent study in the journal Bioscience.
"We are seeing thawing down to 5 meters," says geophysicist Vladimir Romanovsky of the University of Alaska. "A third to a half of permafrost is already within a degree to a degree and a half [Celsius] of thawing."
If only 1% of permafrost carbon were to be released each year, that could double the globe's annual carbon emissions, Romanovsky notes. "We are at a tipping point for positive feedback," he warns, referring to a process in which warming spurs emissions, which in turn generate more heat, in an uncontrollable cycle.
Walter's work is crucial, according to Romanovsky and others, because global warming hinges partly on the ratio of how much carbon is released as CO2 versus how much as methane, a molecule that contains both carbon and hydrogen. Methane, although a far more potent greenhouse gas than carbon dioxide, breaks down more quickly. But when it does, it oxidizes into a carbon dioxide molecule, which can last more than a century in the atmosphere.
Out on the lake, Walter explains: When organic matter (dead plants and animals) rots in the ground, it gives off carbon dioxide. Much of the organic material of thawed permafrost is expected to release carbon dioxide.
But as ice inside permafrost melts, small sinkholes open in the ground and fill with water, joining together to form millions of ponds and lakes. Organic matter slips from eroding shorelines to lake bottoms, where microbes feed on it. Because lake bottoms are oxygen-free, the microbes generate methane in addition to carbon dioxide -- as in the burping La Brea tar pits.
"These lakes are getting bigger -- in some places by a meter a year," Walter says, scooping out slush from the hole she has punched through 6 inches of ice. Into the seep, she inserts a plastic umbrella-like contraption fitted with a bottle to collect gas and a suspended brick to hold it straight.
Before Walter perfected the methane trap, when she was a graduate student in Siberia, she would swim in near-freezing water, dodging leeches and muskrats. Once she caught pneumonia. Another time, her hair caught on fire as she ignited a methane seep.
On the Seward Peninsula trip, she hikes up to 8 miles a day from lake to lake through snowdrifts. Her hip is black and blue from a fall through the ice. "Methane is hard work," she says with a smile.
At each seep, Walter places a small red flag so her colleagues can find the bubbles. Lawrence Plug, a geophysicist from Dalhousie University in Halifax, Canada; Guido Grosse, a German geologist; and Benjamin M. Jones, a U.S. Geological Survey researcher, help shovel off the ice in straight-line paths, take notes on the size of each bubble group, record the location with global positioning system devices, and measure the depth of the lakes.
In the evening, in a cramped cook tent, jars of peanut butter and Nutella sit amid satellite data maps and a textbook on "Applied Linear Statistical Models." Frosted hats and mittens drip from a clothesline. Jones cooks up a batch of hamburger as Walter labels methane bottles with a marker and enters data into her laptop.
Over the next two years, the researchers, funded by the National Science Foundation and NASA, will move between Siberia and Alaska. They will drill permafrost cores, map seeps and analyze data to produce a model of how methane from Arctic lakes might affect Earth's future climate.
"By figuring out how quickly permafrost thawed in the past, we can test our models to predict how fast it could thaw in the next 100 years," says Plug, who will make the complex calculations. "If the temperature warms a couple of degrees Celsius, the lakes could expand at two or three times their current rate."
Elsewhere, scientists cast a wary eye toward clouds of methane bubbles roiling the waters of the Siberian continental shelf. Those emissions, possibly from subsurface permafrost, are even harder to measure than lake emissions.
Meanwhile, researchers are debating the possibility of eventual seeps from methane hydrates -- icy formations beneath the continental shelves and the ocean bottom, and far below land-based permafrost.
Walsh, at the International Arctic Research Center, emphasizes the "huge range of uncertainty" as to how much climate change methane emissions could trigger. "The potential is there for large releases. But there is also a risk of alarmism."
To many Alaskans, it is hardly news that permafrost is thawing: Across the state, houses have been collapsing and trees tipping over. Researchers estimate that repairing affected schools, roads and bridges will cost up to $6 billion over the next two decades.
But the global implications have yet to sink in.
Out on the wild frontier of climate research, far from the legislatures and the diplomatic gatherings where climate policy is debated, Katey Walter and her colleagues focus on what they call "ground truthing."
And beyond that laborious data-gathering, Walter has a mission: to spread the word about what is happening. At the beginning of her field trip, she stops in Nome and leads a group of fifth-graders, many from Alaska Native tribes, out to poke holes in the ice of a nearby lake and light methane flares.
She talks to them about people who live in faraway cities, driving automobiles and working in industries that emit carbon dioxide. And how that causes warming that is felt in the Arctic. And why, even though there are so few people in Alaska, the ice around them is melting.
"That's what we're studying," she explains. "It's all related."
The young woman with curly reddish hair stops, scribbles data, snaps a photo, grabs a heavy metal pick and stabs at white orbs in the thick black ice.
"Every time I see bubbles, I have the same feeling," says Katey Walter, a University of Alaska researcher. "They are amazing and beautiful."
Beautiful, yes. But ominous. When her pick breaks through the surface, the orbs burst with a low gurgle, spewing methane, a potent greenhouse gas that could accelerate the pace of climate change across the globe.
International experts are alarmed. "Methane release due to thawing permafrost in the Arctic is a global warming wild card," warned a report by the United Nations Environment Program last year. Large amounts entering the atmosphere, it concluded, could lead to "abrupt changes in the climate that would likely be irreversible."
Methane (CH4) has at least 20 times the heat-trapping effect of an equivalent amount of carbon dioxide (CO2). As warmer air thaws Arctic soils, as much as 55 billion tons of methane could be released from beneath Siberian lakes alone, according to Walter’s research. That would amount to 10 times the amount currently in the atmosphere.
At 32, Walter, an aquatic ecologist, is a rising star among the thousands of scientists who are struggling to map, measure and predict climate change. Parts of her doctoral dissertation on Siberian lakes were published in three prestigious journals in 2007: Science, Nature and Philosophical Transactions of the Royal Society.
According to one of her studies, methane emissions from Arctic lakes were a major contributor to a period of global warming more than 11,000 years ago.
"It happened on a large scale in the past, and it could happen on a large scale in the future," says Walter, who refers to potential methane emissions as "a time bomb."
Methane levels in the atmosphere have tripled since preindustrial times. Human activities, including rice cultivation, cattle raising and coal mining, account for about 70% of releases, according to recent studies. Natural sources, like tropical wetlands and termites, make up the rest. But those estimates had not incorporated the bubbles Walter was probing on an autumn morning on the Seward Peninsula.
That gurgling gas could change the entire model for predicting global warming. And lakes are not the only methane source: Newly discovered seeps -- places where methane leaks to the surface -- from the shallow waters of Siberia's vast continental shelf are also likely to upset previous assumptions.
Walter's work "has gotten a lot of attention," said John E. Walsh, chief scientist of the International Arctic Research Center in Fairbanks. "She found direct evidence of methane releases in high-latitude lakes. That was not fully realized before."
In a field where the science often seems opaque, Walter's research has a flashy side. She enjoys igniting methane seeps with a cigarette lighter, leaping away as the gas flares as high as 20 feet.
"It's fun," she says. "And it is informative."
Videos of the stunts have swept through the Internet, rare visual evidence of possible danger ahead. At a recent Senate hearing, Al Gore played a clip of her lighting a methane seep. The BBC, the Discovery Channel and the History Channel have featured her in documentaries.
But the complex science of Arctic methane is only beginning to be understood. In the desolate wilderness of the Bering Land Bridge National Preserve, a sense of urgency is palpable among Walter and three fellow researchers, hunkered down in neon-orange tents.
An occasional helicopter ferries supplies from Nome, the closest town, soaring over scattered herds of caribou. A red fox scampers through the brush. Across a snowfield, bear tracks recede into the distance, a reminder that field science isn't for sissies.
"Can you shoot a gun?" Walter asks a visitor, as she heads out to one of 20 lakes she is surveying. When the answer is noncommittal, she hands over bear spray and instructs: "Don't use it until the bear is right up close, facing you."
Nowhere is the evidence of a heating planet more dramatic than in the polar regions. Over the last 50 years, the Arctic has warmed twice as fast as the rest of the globe. Last summer, for the first time in recorded history, the North Pole could be circumnavigated. Ice sheets on Greenland and West Antarctica are melting rapidly. Polar bears and emperor penguins are threatened with extinction.
Even as glaciers and sea ice have captured the most headlines, growing concern is now focused on the transformation of permafrost, soils that are frozen year-round
Today, 20% of Earth's land surface is locked up in a deep freeze. But scientists predict that air temperature in the Arctic is likely to rise as much as 6 degrees Celsius, or 10.8 degrees Fahrenheit, by the end of the century. That is expected to boost the emission of carbon compounds from soils.
The upper 3 meters -- about 10 feet -- of permafrost stores 1.9 trillion tons of carbon, more than double the amount in the atmosphere today, according to a recent study in the journal Bioscience.
"We are seeing thawing down to 5 meters," says geophysicist Vladimir Romanovsky of the University of Alaska. "A third to a half of permafrost is already within a degree to a degree and a half [Celsius] of thawing."
If only 1% of permafrost carbon were to be released each year, that could double the globe's annual carbon emissions, Romanovsky notes. "We are at a tipping point for positive feedback," he warns, referring to a process in which warming spurs emissions, which in turn generate more heat, in an uncontrollable cycle.
Walter's work is crucial, according to Romanovsky and others, because global warming hinges partly on the ratio of how much carbon is released as CO2 versus how much as methane, a molecule that contains both carbon and hydrogen. Methane, although a far more potent greenhouse gas than carbon dioxide, breaks down more quickly. But when it does, it oxidizes into a carbon dioxide molecule, which can last more than a century in the atmosphere.
Out on the lake, Walter explains: When organic matter (dead plants and animals) rots in the ground, it gives off carbon dioxide. Much of the organic material of thawed permafrost is expected to release carbon dioxide.
But as ice inside permafrost melts, small sinkholes open in the ground and fill with water, joining together to form millions of ponds and lakes. Organic matter slips from eroding shorelines to lake bottoms, where microbes feed on it. Because lake bottoms are oxygen-free, the microbes generate methane in addition to carbon dioxide -- as in the burping La Brea tar pits.
"These lakes are getting bigger -- in some places by a meter a year," Walter says, scooping out slush from the hole she has punched through 6 inches of ice. Into the seep, she inserts a plastic umbrella-like contraption fitted with a bottle to collect gas and a suspended brick to hold it straight.
Before Walter perfected the methane trap, when she was a graduate student in Siberia, she would swim in near-freezing water, dodging leeches and muskrats. Once she caught pneumonia. Another time, her hair caught on fire as she ignited a methane seep.
On the Seward Peninsula trip, she hikes up to 8 miles a day from lake to lake through snowdrifts. Her hip is black and blue from a fall through the ice. "Methane is hard work," she says with a smile.
At each seep, Walter places a small red flag so her colleagues can find the bubbles. Lawrence Plug, a geophysicist from Dalhousie University in Halifax, Canada; Guido Grosse, a German geologist; and Benjamin M. Jones, a U.S. Geological Survey researcher, help shovel off the ice in straight-line paths, take notes on the size of each bubble group, record the location with global positioning system devices, and measure the depth of the lakes.
In the evening, in a cramped cook tent, jars of peanut butter and Nutella sit amid satellite data maps and a textbook on "Applied Linear Statistical Models." Frosted hats and mittens drip from a clothesline. Jones cooks up a batch of hamburger as Walter labels methane bottles with a marker and enters data into her laptop.
Over the next two years, the researchers, funded by the National Science Foundation and NASA, will move between Siberia and Alaska. They will drill permafrost cores, map seeps and analyze data to produce a model of how methane from Arctic lakes might affect Earth's future climate.
"By figuring out how quickly permafrost thawed in the past, we can test our models to predict how fast it could thaw in the next 100 years," says Plug, who will make the complex calculations. "If the temperature warms a couple of degrees Celsius, the lakes could expand at two or three times their current rate."
Elsewhere, scientists cast a wary eye toward clouds of methane bubbles roiling the waters of the Siberian continental shelf. Those emissions, possibly from subsurface permafrost, are even harder to measure than lake emissions.
Meanwhile, researchers are debating the possibility of eventual seeps from methane hydrates -- icy formations beneath the continental shelves and the ocean bottom, and far below land-based permafrost.
Walsh, at the International Arctic Research Center, emphasizes the "huge range of uncertainty" as to how much climate change methane emissions could trigger. "The potential is there for large releases. But there is also a risk of alarmism."
To many Alaskans, it is hardly news that permafrost is thawing: Across the state, houses have been collapsing and trees tipping over. Researchers estimate that repairing affected schools, roads and bridges will cost up to $6 billion over the next two decades.
But the global implications have yet to sink in.
Out on the wild frontier of climate research, far from the legislatures and the diplomatic gatherings where climate policy is debated, Katey Walter and her colleagues focus on what they call "ground truthing."
And beyond that laborious data-gathering, Walter has a mission: to spread the word about what is happening. At the beginning of her field trip, she stops in Nome and leads a group of fifth-graders, many from Alaska Native tribes, out to poke holes in the ice of a nearby lake and light methane flares.
She talks to them about people who live in faraway cities, driving automobiles and working in industries that emit carbon dioxide. And how that causes warming that is felt in the Arctic. And why, even though there are so few people in Alaska, the ice around them is melting.
"That's what we're studying," she explains. "It's all related."
It may be vitamin D's day in the sun
Vitamin supplements have been both heralded and hyped over the years, only to ultimately fall from grace once research proves them to be little more than placebos in our quest for longer life or better health. But at least one substance may have true merit -- vitamin D.
Long considered just a supplement consumed with calcium for bone health, this humble vitamin may have untapped potential in fighting or preventing disease, suggests an explosion of new research. Not only has it shown promise in reducing the risk of, among other things, diabetes, pancreatic cancer, breast cancer and cardiovascular disease, but it also seems to improve infertility, weight control and memory.
Two advocacy groups have sprung up in the United States to promote the substance. Food industry executives are exploring ways to fortify more products. And PubMed, an international database of medical literature, shows that 2,274 studies referencing the vitamin have been published -- just this year.
"Vitamin D is one hot topic," says Connie Weaver, a professor of foods and nutrition at Purdue University in Indiana.
Next week, hope and hype may collide. An Institute of Medicine committee will convene in Washington to discuss whether the recommended daily intake of vitamin D and calcium should be increased. There, researchers overwhelmed by the vitamin's potential will square off against skeptics who say much more study is needed before people are urged to take vitamin D supplements. Getting the newly suggested amounts would be difficult otherwise.
The last time guidelines were issued on the vitamin was in 1997, long before an onslaught of scientific information suggested people are getting too little. Currently, the recommended daily intake is 200 to 600 international units with an upper limit of 2,000 IU.
Some researchers are advocating at least 600 IU a day, with an upper limit of 10,000 IU. Giving impetus to this push are the facts that many people seem to be deficient and that the nutrient appears to play a role in many conditions.
--------------------------------------------------------------------------------
FOR THE RECORD:
In Saturday's Section A, an article about vitamin D incorrectly referred to the substance in the skin as melatonin. It's melanin.
--------------------------------------------------------------------------------
Other scientists say it's too soon to urge everyone to take supplements. An influential report released in June by the Agency for Healthcare Research and Quality found little conclusive evidence to support increasing the recommended amounts.
"I think there is a consensus that we might benefit from higher vitamin D levels," says James C. Fleet, a professor of foods and nutrition at Purdue University and a longtime researcher on the vitamin and prostate cancer. "But the committee is going to ask whether there is existing scientific evidence that is strong enough to make a change."
Vitamin D has long been known to be crucial to bone and muscle health by improving calcium absorption in the intestines and the way calcium is regulated in bones.
More recent research shows that receptors for it are found in almost every organ and tissue system in the body, suggesting that deficiencies may affect many types of cell functions.
When exposed to sunlight, the skin makes the vitamin, but not everyone spends the five minutes a day or so outside that is necessary for synthesis -- and many more people today wear sunscreen to prevent skin cancer.
"A large portion of people fall into the at-risk category, and they would benefit from being brought out of that category," Fleet says. "The question is: Is the current requirement enough to keep most people out of the at-risk category?"
A study of 13,000 Americans, published in March in the Archives of Internal Medicine, found that 50% to 75% have suboptimal levels by current standards. A level of 20 nanograms per milliliter of 25-hydroxyvitamin D -- the form most commonly measured in blood -- has traditionally been considered sufficient.
Most people 50 and older aren't meeting the current recommendations, Weaver says.
The vitamin is found in relatively few dietary sources -- some fortified foods, such as milk and some cereals, and naturally only in some fatty fish, such as salmon. Three cups of fortified milk provide only 300 IU.
"The largest source is sunshine, but not everyone can depend on that," Weaver says. "The elderly, dark-skinned people, higher-latitude dwellers all have trouble getting enough from sun." In darker-skinned people, melatonin in the skin blocks absorption of the ultraviolet rays needed to make the vitamin; older people don't appear to synthesize it from the sun as well as younger people.
Some scientists argue that levels of 40 to 60 ng/mL would be far better for disease prevention. That would require daily intake much higher than the current 200 to 600 IU.
The July issue of the Annals of Epidemiology(09)X0007-4, devoted to vitamin D research, links the vitamin to lower risks of cancers of the breast, colon, ovaries and prostate. Animal and lab studies also demonstrate its importance in many of the cellular mechanisms that control cancer, such as cell growth, cell death, inflammation and DNA repair.
Five studies on colorectal cancer and breast cancer, taken together, showed that people with levels higher than 34 to 52 ng/mL had a 50% reduced cancer risk, says Cindy D. Davis, a researcher at the National Cancer Institute's Nutritional Science Research Group.
Such studies are not proof that the vitamin influences disease development, points out Dr. Karen E. Hansen, an assistant professor at the University of Wisconsin who studies bone health. "People with higher vitamin D may just be healthier for other reasons," she says.
But evidence linking higher blood levels to diabetes and cardiovascular disease is also mounting. A study in December in the Journal of the American College of Cardiology found that deficiency may increase the risk of cardiovascular disease. Other studies have tied lower levels to an increased risk of hypertension, diabetes, stroke and congestive heart failure.
Even for bone health, some studies suggest that about 700 to 800 IU a day are needed to prevent fractures in people over 50, Hansen says. She recommends 800 IU a day, with calcium, to her patients.
Meanwhile, studies show that the previous estimation of a toxic dose -- 2,000 IU a day -- is most likely too conservative. Toxic doses can lead to a dangerous level of calcium in the blood, high blood pressure and even kidney failure.
"It's likely they will increase their recommendation for all ages," Hanson said of the Institute of Medicine committee, which will release its report next year.
But not everyone is convinced the advice should be changed. In a report ordered by the federal government to assist the committee, researchers concluded there is a lack of strong evidence to support altering recommendations. The committee is not expected to change calcium recommendations.
"We did not find data that indicate a specific level of vitamin D intake is associated with adverse outcomes or beneficial health outcomes," said Dr. Thomas A. Trikalinos, co-director of the Tufts Evidence-based Practice Center, which prepared the report.
He said the report was meant to inform the committee and did not make recommendations.
"The report sees the totality of the evidence and tries to put everything into perspective," Trikalinos says.
Already, however, the American Society of Clinical Oncology has recommended a higher intake for breast cancer patients who are deficient.
In October, the American Academy of Pediatrics said children should get 400 IU a day, double the current recommendation.
In November, 18 University of California researchers issued a statement saying 2,000 IU is appropriate for most people.
"I think some of the more vocal advocates are pushing the medical community to move forward" before adequate research is completed, Fleet says.
Dozens of more scientifically rigorous studies are in progress that could help resolve the questions about how much people should consume.
"I think they held this [Institute of Medicine] meeting two to four years too early," Fleet says. "They are working without the big wave of vitamin D research that was initiated after people started pushing for it."
Long considered just a supplement consumed with calcium for bone health, this humble vitamin may have untapped potential in fighting or preventing disease, suggests an explosion of new research. Not only has it shown promise in reducing the risk of, among other things, diabetes, pancreatic cancer, breast cancer and cardiovascular disease, but it also seems to improve infertility, weight control and memory.
Two advocacy groups have sprung up in the United States to promote the substance. Food industry executives are exploring ways to fortify more products. And PubMed, an international database of medical literature, shows that 2,274 studies referencing the vitamin have been published -- just this year.
"Vitamin D is one hot topic," says Connie Weaver, a professor of foods and nutrition at Purdue University in Indiana.
Next week, hope and hype may collide. An Institute of Medicine committee will convene in Washington to discuss whether the recommended daily intake of vitamin D and calcium should be increased. There, researchers overwhelmed by the vitamin's potential will square off against skeptics who say much more study is needed before people are urged to take vitamin D supplements. Getting the newly suggested amounts would be difficult otherwise.
The last time guidelines were issued on the vitamin was in 1997, long before an onslaught of scientific information suggested people are getting too little. Currently, the recommended daily intake is 200 to 600 international units with an upper limit of 2,000 IU.
Some researchers are advocating at least 600 IU a day, with an upper limit of 10,000 IU. Giving impetus to this push are the facts that many people seem to be deficient and that the nutrient appears to play a role in many conditions.
--------------------------------------------------------------------------------
FOR THE RECORD:
In Saturday's Section A, an article about vitamin D incorrectly referred to the substance in the skin as melatonin. It's melanin.
--------------------------------------------------------------------------------
Other scientists say it's too soon to urge everyone to take supplements. An influential report released in June by the Agency for Healthcare Research and Quality found little conclusive evidence to support increasing the recommended amounts.
"I think there is a consensus that we might benefit from higher vitamin D levels," says James C. Fleet, a professor of foods and nutrition at Purdue University and a longtime researcher on the vitamin and prostate cancer. "But the committee is going to ask whether there is existing scientific evidence that is strong enough to make a change."
Vitamin D has long been known to be crucial to bone and muscle health by improving calcium absorption in the intestines and the way calcium is regulated in bones.
More recent research shows that receptors for it are found in almost every organ and tissue system in the body, suggesting that deficiencies may affect many types of cell functions.
When exposed to sunlight, the skin makes the vitamin, but not everyone spends the five minutes a day or so outside that is necessary for synthesis -- and many more people today wear sunscreen to prevent skin cancer.
"A large portion of people fall into the at-risk category, and they would benefit from being brought out of that category," Fleet says. "The question is: Is the current requirement enough to keep most people out of the at-risk category?"
A study of 13,000 Americans, published in March in the Archives of Internal Medicine, found that 50% to 75% have suboptimal levels by current standards. A level of 20 nanograms per milliliter of 25-hydroxyvitamin D -- the form most commonly measured in blood -- has traditionally been considered sufficient.
Most people 50 and older aren't meeting the current recommendations, Weaver says.
The vitamin is found in relatively few dietary sources -- some fortified foods, such as milk and some cereals, and naturally only in some fatty fish, such as salmon. Three cups of fortified milk provide only 300 IU.
"The largest source is sunshine, but not everyone can depend on that," Weaver says. "The elderly, dark-skinned people, higher-latitude dwellers all have trouble getting enough from sun." In darker-skinned people, melatonin in the skin blocks absorption of the ultraviolet rays needed to make the vitamin; older people don't appear to synthesize it from the sun as well as younger people.
Some scientists argue that levels of 40 to 60 ng/mL would be far better for disease prevention. That would require daily intake much higher than the current 200 to 600 IU.
The July issue of the Annals of Epidemiology(09)X0007-4, devoted to vitamin D research, links the vitamin to lower risks of cancers of the breast, colon, ovaries and prostate. Animal and lab studies also demonstrate its importance in many of the cellular mechanisms that control cancer, such as cell growth, cell death, inflammation and DNA repair.
Five studies on colorectal cancer and breast cancer, taken together, showed that people with levels higher than 34 to 52 ng/mL had a 50% reduced cancer risk, says Cindy D. Davis, a researcher at the National Cancer Institute's Nutritional Science Research Group.
Such studies are not proof that the vitamin influences disease development, points out Dr. Karen E. Hansen, an assistant professor at the University of Wisconsin who studies bone health. "People with higher vitamin D may just be healthier for other reasons," she says.
But evidence linking higher blood levels to diabetes and cardiovascular disease is also mounting. A study in December in the Journal of the American College of Cardiology found that deficiency may increase the risk of cardiovascular disease. Other studies have tied lower levels to an increased risk of hypertension, diabetes, stroke and congestive heart failure.
Even for bone health, some studies suggest that about 700 to 800 IU a day are needed to prevent fractures in people over 50, Hansen says. She recommends 800 IU a day, with calcium, to her patients.
Meanwhile, studies show that the previous estimation of a toxic dose -- 2,000 IU a day -- is most likely too conservative. Toxic doses can lead to a dangerous level of calcium in the blood, high blood pressure and even kidney failure.
"It's likely they will increase their recommendation for all ages," Hanson said of the Institute of Medicine committee, which will release its report next year.
But not everyone is convinced the advice should be changed. In a report ordered by the federal government to assist the committee, researchers concluded there is a lack of strong evidence to support altering recommendations. The committee is not expected to change calcium recommendations.
"We did not find data that indicate a specific level of vitamin D intake is associated with adverse outcomes or beneficial health outcomes," said Dr. Thomas A. Trikalinos, co-director of the Tufts Evidence-based Practice Center, which prepared the report.
He said the report was meant to inform the committee and did not make recommendations.
"The report sees the totality of the evidence and tries to put everything into perspective," Trikalinos says.
Already, however, the American Society of Clinical Oncology has recommended a higher intake for breast cancer patients who are deficient.
In October, the American Academy of Pediatrics said children should get 400 IU a day, double the current recommendation.
In November, 18 University of California researchers issued a statement saying 2,000 IU is appropriate for most people.
"I think some of the more vocal advocates are pushing the medical community to move forward" before adequate research is completed, Fleet says.
Dozens of more scientifically rigorous studies are in progress that could help resolve the questions about how much people should consume.
"I think they held this [Institute of Medicine] meeting two to four years too early," Fleet says. "They are working without the big wave of vitamin D research that was initiated after people started pushing for it."
Groups to challenge legality of closing 100 California state parks
Minority and low-income communities would suffer first and worst from a plan to cut the state budget by closing as many as 100 California state parks and beaches, according to a group of nonprofit health organizations and concerned citizens expected to file an administrative complaint with the U.S. Justice Department on Monday.
State officials hope to finalize a list of park closures by Labor Day. But the group led by the City Project, Concerned Citizens of South Los Angeles, Coastwalk California, the California Pan-Ethnic Health Network and the California Center for Public Health Advocacy contends that closing a third of the state's parks would violate laws prohibiting discriminatory impacts on recipients of federal and state funds.
“This issue must be resolved as soon as possible,” said Zoe Rawson, staff attorney for the City Project. “Access to open space is critical to the well-being and health of people who reside in densely populated urban environments such as Los Angeles."
“The values at stake are great," she said, "and include social cohesion, and the psychological and physical health of thousands of people who can’t afford to go to a gym."
The complaint will be submitted against California Gov. Arnold Schwarzenegger, the California state legislature and the California Resources Agency, the group said.
"With the complaint we are seeking ultimately to prevent or mitigate state park closures," she said. "If we can't resolve this issue through the complaint process, the next step we will be considering is a lawsuit."
State officials hope to finalize a list of park closures by Labor Day. But the group led by the City Project, Concerned Citizens of South Los Angeles, Coastwalk California, the California Pan-Ethnic Health Network and the California Center for Public Health Advocacy contends that closing a third of the state's parks would violate laws prohibiting discriminatory impacts on recipients of federal and state funds.
“This issue must be resolved as soon as possible,” said Zoe Rawson, staff attorney for the City Project. “Access to open space is critical to the well-being and health of people who reside in densely populated urban environments such as Los Angeles."
“The values at stake are great," she said, "and include social cohesion, and the psychological and physical health of thousands of people who can’t afford to go to a gym."
The complaint will be submitted against California Gov. Arnold Schwarzenegger, the California state legislature and the California Resources Agency, the group said.
"With the complaint we are seeking ultimately to prevent or mitigate state park closures," she said. "If we can't resolve this issue through the complaint process, the next step we will be considering is a lawsuit."
Tie your tubes and save the planet?
Environmentalists tend to avoid the topic of population control. Too touchy. But the politically incorrect issue is becoming unavoidable as the global population lurches toward a predicted 9 billion people by mid-century. Will there be enough food? Enough water? Will planet-heating carbon dioxide gas become ever more uncontrollable?
Now comes a study by statisticians at Oregon State University focusing on the elephant in the room. If you are serious about your carbon footprint, think: birth control.
The greenhouse gas impact of an extra child is almost 20 times more significant than the amount any American would save by such practices as driving a fuel-efficient car, recycling or using energy-efficient light bulbs and appliances, according to Paul Murtaugh, an OSU professor of statistics. Under current U.S. consumption patterns, each child ultimately adds about 9,441 metric tons of CO2 to the carbon legacy of an average parent--about 5.7 times a person's lifetime emissions, he calculates.
"Many people are unaware of the power of exponential population growth," Murtaugh said. "Future growth amplifies the consequences of people's reproductive choices, the same way that compound interest amplifies a bank balance."
Given how much less the average developing nation consumes per capita, the impact of a child born in the U.S., along with all his or her descendants, is more than 160 times that of a Bangladeshi child, the OSU research found. And the long-term impact of a Chinese child is less than one fifth the impact of a U.S.-born child. But as China, India and other developing nations hurtle toward prosperity, that is likely to change
Now comes a study by statisticians at Oregon State University focusing on the elephant in the room. If you are serious about your carbon footprint, think: birth control.
The greenhouse gas impact of an extra child is almost 20 times more significant than the amount any American would save by such practices as driving a fuel-efficient car, recycling or using energy-efficient light bulbs and appliances, according to Paul Murtaugh, an OSU professor of statistics. Under current U.S. consumption patterns, each child ultimately adds about 9,441 metric tons of CO2 to the carbon legacy of an average parent--about 5.7 times a person's lifetime emissions, he calculates.
"Many people are unaware of the power of exponential population growth," Murtaugh said. "Future growth amplifies the consequences of people's reproductive choices, the same way that compound interest amplifies a bank balance."
Given how much less the average developing nation consumes per capita, the impact of a child born in the U.S., along with all his or her descendants, is more than 160 times that of a Bangladeshi child, the OSU research found. And the long-term impact of a Chinese child is less than one fifth the impact of a U.S.-born child. But as China, India and other developing nations hurtle toward prosperity, that is likely to change
Causes of cancer clusters are hard to find
It has taken health investigators two years of research to designate Clyde, Ohio, a cancer cluster.
Their inquiry started soon after Donna and Dave Hisey's 13-year-old daughter was diagnosed with acute myelogenous leukemia.
While the Hiseys awaited the study results, disaster struck again. Their middle child, Tanner, developed lumps on his neck, and in August, he was diagnosed with a totally different form of leukemia, acute lymphoblastic T-cell leukemia. The cluster confirmation came in May, as Tanner underwent chemotherapy.
Now, says Donna Hisey, she checks her youngest child, Siera, every day for signs of illness. The sense of fear is ever-present. The need to know what caused the cancer is overwhelming. It has taken over their lives.
"Any time anybody gets sick, people freak out. Is it minor?" said Hisey, a line worker at the nearby Whirlpool plant. "We just want to know what caused this so nobody else gets sick."
It is not yet known whether The Acreage is a cancer cluster. The state is studying the possibility.
But as families anxiously await results of the state's study here, they're convinced the cluster exists and are deeply hungry to find out what is behind the illnesses in their community.
Could it have been something that leached into the groundwater from the nearby Pratt & Whitney plant decades ago? Something toxic or radioactive in the soil brought in to raise their houses above the marsh? Some solvent illegally dumped and buried? Or the pesticides used in the nearby orange groves and sugar cane fields?
A look at cancer cluster investigations elsewhere in the United States suggests that definitive answers will be difficult - but not impossible - to come by. In the process of searching though, communities like Clyde, Ohio, and The Acreage are learning truths about themselves and their surroundings that can be deeply unsettling.
According to one Acreage resident's unscientific tally, there have been at least eight cases of a brain tumor called glioblastoma multiforme between 2004 and 2009; five cases of a sometimes benign brain tumor called meningioma since 2003; and 17 other assorted brain and nervous system tumors since 1998 - all within the patch of 50,000 rural homes.
The exact case count is hard to say. State health officials are analyzing data from the national cancer registry over 12 years, data that's compiled whenever there is a cancer diagnosis. They will calculate the rate of the cancers they find in the local population, then compare it to national cancer rates. Results may take several weeks.
Meanwhile, state environmental officials are beginning to sample wells, while county leaders analyze soil at two schools.
"It's in the water. I know it's in the water. I really believe it," said Mack Purifoy, 58, who retired to his dream home in The Acreage four years ago with his wife and nephew. The home he paid $400,000 for has a Jacuzzi, an attractive new façade, and well water. And it's sitting empty. He refuses to live there. The former owner, he was told, died of cancer.
A year after moving in, his nephew developed lymphoma. A few months ago, doctors discovered a growth in his brain. They don't know yet if it's a cyst or a tumor, Purifoy said, only that it's growing. He's losing his sense of balance, and having trouble with his vision.
"I drank that water," he says, his voice tinged with anger.
Purifoy is dubious that investigators will ever really identify the source of the illnesses.
Once a cancer cluster is identified, under protocols from the U.S. Centers for Disease Control and Prevention, environmental investigators begin considering possible causes: sources of radiation, pesticides, fungicides, solvents, other chemicals.
Sometimes they find a cause. Often they don't. Frequently, politics trumps science.
In Cameron, Mo., last fall Missouri state officials told residents that the 70 brain cancer cases they identified in a four-county area over 12 years did not represent a cancer cluster.
Several months later, a lawsuit alleged that a leather tannery had been dumping highly dangerous chromium 6, the subject of the film Erin Brockovich, into waste sludge that was spread on farm fields in the region since the 1980s, The Kansas City Star reported. Subsequent sampling of farm fields did find low levels of the hazardous chromium 6, a proven carcinogen.
In eastern Pennsylvania, a single type of rare blood cancer, polycythemia vera, was found in dozens of people. A $5.5 million study is under way, and is considering seven waste coal power plants in the area and seven Superfund sites. At a congressional hearing in March, Democratic lawmakers blasted the Agency for Toxic Substances and Disease Registry, a sister agency to the CDC, for its shoddy review of the cancer cluster.
A report by the congressional committee's staff called the agency's handling of such cases a "clear and present danger" to public health.
"Time and time again ATSDR appears to avoid clearly and directly confronting the most obvious toxic culprits that harm the health of local communities throughout the nation," said the report by the Majority Staff of the Subcommittee on Investigations and Oversight of the Committee on Science and Technology. "Instead, they deny, delay, minimize, trivialize or ignore legitimate concerns and health considerations of local communities and well respected scientists and medical professionals."
In Clyde, Ohio, the investigation is being handled by the state, with input from federal officials, said Robert Indian, chief of comprehensive cancer control for the Ohio Department of Health.
They are broadening their research to study birth defects and miscarriages, he said. There have been 20 children with brain tumors in the area. The nature of the cancers, leukemias and brain tumors, suggests ionizing radiation, Indian said, although everything is being considered.
Not far from Clyde, Waste Management, Inc. operates a deep-well-injection site that has been collecting liquid pesticides and other hazardous chemical waste from throughout the nation. Called Vickery Environmental, the firm injects the waste 3,000 feet into a rock formation deep below farm fields, the company says.
Donna Hisey can't help but wonder if that's the source of the cancers. But she's been told the chemicals have not migrated. She wonders if it's true.
Her best advice to people in The Acreage is to stay involved, ask questions, and keep digging.
Purifoy is asking those questions, but he despairs that he will get an answer in his lifetime.
"We're all going to be dead by the time you all figure out what's going on," he told state environmental leaders at an emotionally charged community meeting on Thursday. "They are going to sweep it under the rug, and a lot of people are going to die, and that's just the way it is."
Hisey said she wants to trust the people who are investigating the Clyde, Ohio, cluster. She needs to be able to trust them. She prays about it often. Ultimately, she said, it's in God's hands.
"I don't know if they are ever going to find out what caused it or not. I would love for them to tell us an answer," Hisey said. "But if they put their best effort into it and they can't find it, then we will have to accept it. But at least we will know they tried."
Their inquiry started soon after Donna and Dave Hisey's 13-year-old daughter was diagnosed with acute myelogenous leukemia.
While the Hiseys awaited the study results, disaster struck again. Their middle child, Tanner, developed lumps on his neck, and in August, he was diagnosed with a totally different form of leukemia, acute lymphoblastic T-cell leukemia. The cluster confirmation came in May, as Tanner underwent chemotherapy.
Now, says Donna Hisey, she checks her youngest child, Siera, every day for signs of illness. The sense of fear is ever-present. The need to know what caused the cancer is overwhelming. It has taken over their lives.
"Any time anybody gets sick, people freak out. Is it minor?" said Hisey, a line worker at the nearby Whirlpool plant. "We just want to know what caused this so nobody else gets sick."
It is not yet known whether The Acreage is a cancer cluster. The state is studying the possibility.
But as families anxiously await results of the state's study here, they're convinced the cluster exists and are deeply hungry to find out what is behind the illnesses in their community.
Could it have been something that leached into the groundwater from the nearby Pratt & Whitney plant decades ago? Something toxic or radioactive in the soil brought in to raise their houses above the marsh? Some solvent illegally dumped and buried? Or the pesticides used in the nearby orange groves and sugar cane fields?
A look at cancer cluster investigations elsewhere in the United States suggests that definitive answers will be difficult - but not impossible - to come by. In the process of searching though, communities like Clyde, Ohio, and The Acreage are learning truths about themselves and their surroundings that can be deeply unsettling.
According to one Acreage resident's unscientific tally, there have been at least eight cases of a brain tumor called glioblastoma multiforme between 2004 and 2009; five cases of a sometimes benign brain tumor called meningioma since 2003; and 17 other assorted brain and nervous system tumors since 1998 - all within the patch of 50,000 rural homes.
The exact case count is hard to say. State health officials are analyzing data from the national cancer registry over 12 years, data that's compiled whenever there is a cancer diagnosis. They will calculate the rate of the cancers they find in the local population, then compare it to national cancer rates. Results may take several weeks.
Meanwhile, state environmental officials are beginning to sample wells, while county leaders analyze soil at two schools.
"It's in the water. I know it's in the water. I really believe it," said Mack Purifoy, 58, who retired to his dream home in The Acreage four years ago with his wife and nephew. The home he paid $400,000 for has a Jacuzzi, an attractive new façade, and well water. And it's sitting empty. He refuses to live there. The former owner, he was told, died of cancer.
A year after moving in, his nephew developed lymphoma. A few months ago, doctors discovered a growth in his brain. They don't know yet if it's a cyst or a tumor, Purifoy said, only that it's growing. He's losing his sense of balance, and having trouble with his vision.
"I drank that water," he says, his voice tinged with anger.
Purifoy is dubious that investigators will ever really identify the source of the illnesses.
Once a cancer cluster is identified, under protocols from the U.S. Centers for Disease Control and Prevention, environmental investigators begin considering possible causes: sources of radiation, pesticides, fungicides, solvents, other chemicals.
Sometimes they find a cause. Often they don't. Frequently, politics trumps science.
In Cameron, Mo., last fall Missouri state officials told residents that the 70 brain cancer cases they identified in a four-county area over 12 years did not represent a cancer cluster.
Several months later, a lawsuit alleged that a leather tannery had been dumping highly dangerous chromium 6, the subject of the film Erin Brockovich, into waste sludge that was spread on farm fields in the region since the 1980s, The Kansas City Star reported. Subsequent sampling of farm fields did find low levels of the hazardous chromium 6, a proven carcinogen.
In eastern Pennsylvania, a single type of rare blood cancer, polycythemia vera, was found in dozens of people. A $5.5 million study is under way, and is considering seven waste coal power plants in the area and seven Superfund sites. At a congressional hearing in March, Democratic lawmakers blasted the Agency for Toxic Substances and Disease Registry, a sister agency to the CDC, for its shoddy review of the cancer cluster.
A report by the congressional committee's staff called the agency's handling of such cases a "clear and present danger" to public health.
"Time and time again ATSDR appears to avoid clearly and directly confronting the most obvious toxic culprits that harm the health of local communities throughout the nation," said the report by the Majority Staff of the Subcommittee on Investigations and Oversight of the Committee on Science and Technology. "Instead, they deny, delay, minimize, trivialize or ignore legitimate concerns and health considerations of local communities and well respected scientists and medical professionals."
In Clyde, Ohio, the investigation is being handled by the state, with input from federal officials, said Robert Indian, chief of comprehensive cancer control for the Ohio Department of Health.
They are broadening their research to study birth defects and miscarriages, he said. There have been 20 children with brain tumors in the area. The nature of the cancers, leukemias and brain tumors, suggests ionizing radiation, Indian said, although everything is being considered.
Not far from Clyde, Waste Management, Inc. operates a deep-well-injection site that has been collecting liquid pesticides and other hazardous chemical waste from throughout the nation. Called Vickery Environmental, the firm injects the waste 3,000 feet into a rock formation deep below farm fields, the company says.
Donna Hisey can't help but wonder if that's the source of the cancers. But she's been told the chemicals have not migrated. She wonders if it's true.
Her best advice to people in The Acreage is to stay involved, ask questions, and keep digging.
Purifoy is asking those questions, but he despairs that he will get an answer in his lifetime.
"We're all going to be dead by the time you all figure out what's going on," he told state environmental leaders at an emotionally charged community meeting on Thursday. "They are going to sweep it under the rug, and a lot of people are going to die, and that's just the way it is."
Hisey said she wants to trust the people who are investigating the Clyde, Ohio, cluster. She needs to be able to trust them. She prays about it often. Ultimately, she said, it's in God's hands.
"I don't know if they are ever going to find out what caused it or not. I would love for them to tell us an answer," Hisey said. "But if they put their best effort into it and they can't find it, then we will have to accept it. But at least we will know they tried."
Scientists claim planet is heading for 'irreversible' climate change by 2040
CARBON dioxide levels are rising at a faster rate than the worst-case scenario envisaged by United Nations experts, with the planet heading for "catastrophic" and "irreversible" climate change by 2040, a new report claims.
The rise of greenhouse gases will trigger an unprecedented rate of global warming that will result in the loss of the ice-covered polar seas by 2020, much of our coral reefs by 2040 and see a 1.4-metre rise in the sea level by 2100.
The apocalyptic vision has been outlined in a paper by Andrew Brierley of St Andrews University, which is likely to influence the views of UN experts gathering in Copenhagen this December to establish a new protocol that will attempt to halt global warming.
Brierley and his co-author, Michael Kingsford of the James Cook University in Australia, examined the effect of carbon dioxide emissions on ocean habitats and marine organisms.
The scientists compared current carbon dioxide emissions with those forecast in 2007 by the Intergovernmental Panel of Climate Change (IPCC), the leading body for the assessment of global warming, which was established by the United Nations Environment Programme and the World Meteorological Organisation.
In 2007, the IPCC predicted a "worst-case scenario" that would see rapid industrialisation cause carbon dioxide in the atmosphere to increase by two parts per million each year. Parts per million (ppm) is a unit of concentration used to measure pollutants.
Brierley said atmospheric carbon dioxide concentration had increased from pre-industrial levels of 280 ppm to 385 ppm last year and was now rising at a rate of 2.5 ppm per year.
He described the outlook as "really quite nasty doom-and-gloom situation".
He added: "People have looked at how various economic situations, various developments in India and China might impact on carbon dioxide admissions and in 2007 they made a series of forecasts and if you take the worst-case scenario, carbon dioxide would be going up by two parts per million.
"This really august body, the Intergovernmental Panel on Climate Change, has said these are the worst-case scenarios for carbon dioxide increase and we are above that already. That's the thing that really frightens me."
In their paper, Brierley and Kingsford said that a carbon dioxide level of 450 ppm was the critical threshold beyond which catastrophic and irreversible change might occur.
Reaching that level would mean a global mean temperature rise of 2C above pre-industrial values. At present rates this threshold will be passed by 2040.
The authors added: "By 2040, some particularly sensitive marine ecosystems such as coral reefs and ice-covered polar seas could already have been lost and other unexpected consequences may arise."
Brierley said: "You can say no Arctic sea ice by 2020 – really, really soon. Certainly no summer sea ice in the Arctic by 2020."
The rise of greenhouse gases will trigger an unprecedented rate of global warming that will result in the loss of the ice-covered polar seas by 2020, much of our coral reefs by 2040 and see a 1.4-metre rise in the sea level by 2100.
The apocalyptic vision has been outlined in a paper by Andrew Brierley of St Andrews University, which is likely to influence the views of UN experts gathering in Copenhagen this December to establish a new protocol that will attempt to halt global warming.
Brierley and his co-author, Michael Kingsford of the James Cook University in Australia, examined the effect of carbon dioxide emissions on ocean habitats and marine organisms.
The scientists compared current carbon dioxide emissions with those forecast in 2007 by the Intergovernmental Panel of Climate Change (IPCC), the leading body for the assessment of global warming, which was established by the United Nations Environment Programme and the World Meteorological Organisation.
In 2007, the IPCC predicted a "worst-case scenario" that would see rapid industrialisation cause carbon dioxide in the atmosphere to increase by two parts per million each year. Parts per million (ppm) is a unit of concentration used to measure pollutants.
Brierley said atmospheric carbon dioxide concentration had increased from pre-industrial levels of 280 ppm to 385 ppm last year and was now rising at a rate of 2.5 ppm per year.
He described the outlook as "really quite nasty doom-and-gloom situation".
He added: "People have looked at how various economic situations, various developments in India and China might impact on carbon dioxide admissions and in 2007 they made a series of forecasts and if you take the worst-case scenario, carbon dioxide would be going up by two parts per million.
"This really august body, the Intergovernmental Panel on Climate Change, has said these are the worst-case scenarios for carbon dioxide increase and we are above that already. That's the thing that really frightens me."
In their paper, Brierley and Kingsford said that a carbon dioxide level of 450 ppm was the critical threshold beyond which catastrophic and irreversible change might occur.
Reaching that level would mean a global mean temperature rise of 2C above pre-industrial values. At present rates this threshold will be passed by 2040.
The authors added: "By 2040, some particularly sensitive marine ecosystems such as coral reefs and ice-covered polar seas could already have been lost and other unexpected consequences may arise."
Brierley said: "You can say no Arctic sea ice by 2020 – really, really soon. Certainly no summer sea ice in the Arctic by 2020."
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