Twenty Years Later
Tipping Points Near On Global Warming
by James Hansen
The Huffington Post (June 23 2008)
http://www.countercurrents.org (June 25 2008)
I testified to Congress about global warming, twenty years after my June 23 1988 testimony, which alerted the public that global warming was underway. There are striking similarities between then and now, but one big difference.
Again a wide gap has developed between what is understood about global warming by the relevant scientific community and what is known by policymakers and the public. Now, as then, frank assessment of scientific data yields conclusions that are shocking to the body politic. Now, as then, I can assert that these conclusions have a certainty exceeding 99 percent.
The difference is that now we have used up all slack in the schedule for actions needed to defuse the global warming time bomb. The next president and Congress must define a course next year in which the United States exerts leadership commensurate with our responsibility for the present dangerous situation.
Otherwise it will become impractical to constrain atmospheric carbon dioxide, the greenhouse gas produced in burning fossil fuels, to a level that prevents the climate system from passing tipping points that lead to disastrous climate changes that spiral dynamically out of humanity's control.
Changes needed to preserve creation, the planet on which civilization developed, are clear. But the changes have been blocked by special interests, focused on short-term profits, who hold sway in Washington and other capitals.
I argue that a path yielding energy independence and a healthier environment is, barely, still possible. It requires a transformative change of direction in Washington in the next year.
On June 23 1988 I testified to a hearing, organized by Senator Tim Wirth of Colorado, that the Earth had entered a long-term warming trend and that human-made greenhouse gases almost surely were responsible. I noted that global warming enhanced both extremes of the water cycle, meaning stronger droughts and forest fires, on the one hand, but also heavier rains and floods.
My testimony two decades ago was greeted with skepticism. But while skepticism is the lifeblood of science, it can confuse the public. As scientists examine a topic from all perspectives, it may appear that nothing is known with confidence. But from such broad open-minded study of all data, valid conclusions can be drawn.
My conclusions in 1988 were built on a wide range of inputs from basic physics, planetary studies, observations of on-going changes, and climate models. The evidence was strong enough that I could say it was time to "stop waffling". I was sure that time would bring the scientific community to a similar consensus, as it has.
While international recognition of global warming was swift, actions have faltered. The US refused to place limits on its emissions, and developing countries such as China and India rapidly increased their emissions.
What is at stake? Warming so far, about two degrees Fahrenheit over land areas, seems almost innocuous, being less than day-to-day weather fluctuations. But more warming is already "in the pipeline", delayed only by the great inertia of the world ocean. And climate is nearing dangerous tipping points. Elements of a "perfect storm", a global cataclysm, are assembled.
Climate can reach points such that amplifying feedbacks spur large rapid changes. Arctic sea ice is a current example. Global warming initiated sea ice melt, exposing darker ocean that absorbs more sunlight, melting more ice. As a result, without any additional greenhouse gases, the Arctic soon will be ice-free in the summer.
More ominous tipping points loom. West Antarctic and Greenland ice sheets are vulnerable to even small additional warming. These two-mile-thick behemoths respond slowly at first, but if disintegration gets well under way, it will become unstoppable. Debate among scientists is only about how much sea level would rise by a given date. In my opinion, if emissions follow a business-as-usual scenario, sea level rise of at least two meters is likely within a century. Hundreds of millions of people would become refugees, and no stable shoreline would be reestablished in any time frame that humanity can conceive.
Animal and plant species are already being stressed by climate change. Species can migrate in response to movement of their climatic zone, but some species in polar and alpine regions will be pushed off the planet. As climate zones move farther and faster, climate change will become the primary cause of species extinction. The tipping point for life on the planet will occur when so many interdependent species are lost that ecosystems collapse.
The shocking conclusion, documented in a paper I have written with several of the world's leading climate experts, is that the safe level of atmospheric carbon dioxide is no more than 350 ppm (parts per million), and it may be less. Carbon dioxide amount is already 385 ppm and rising about two ppm per year. Shocking corollary: the oft-stated goal to keep global warming less than two degrees Celsius (3.6 degrees Fahrenheit) is a recipe for global disaster, not salvation.
These conclusions are based on paleoclimate data showing how the Earth responded to past levels of greenhouse gases and on observations showing how the world is responding to today's carbon dioxide amount. The consequences of continued increase of greenhouse gases extend far beyond extermination of species and future sea level rise.
Arid subtropical climate zones are expanding poleward. Already an average expansion of about 250 miles has occurred, affecting the southern United States, the Mediterranean region, Australia and southern Africa. Forest fires and drying-up of lakes will increase further unless carbon dioxide growth is halted and reversed.
Mountain glaciers are the source of fresh water for hundreds of millions of people. These glaciers are receding world-wide, in the Himalayas, Andes and Rocky Mountains. They will disappear, leaving their rivers as trickles in late summer and fall, unless the growth of carbon dioxide is reversed.
Coral reefs, the rainforest of the ocean, are home to one-third of the species in the sea. Coral reefs are under stress for several reasons, including warming of the ocean, but especially because of ocean acidification, a direct effect of added carbon dioxide. Ocean life dependent on carbonate shells and skeletons is threatened by dissolution as the ocean becomes more acid.
Such phenomena, including the instability of Arctic sea ice and the great ice sheets at today's carbon dioxide amount, show that we have already gone too far. We must draw down atmospheric carbon dioxide to preserve the planet we know. A level of no more than 350 ppm is still feasible, with the help of reforestation and improved agricultural practices, but just barely - time is running out.
The steps needed to halt carbon dioxide growth follow from the size of fossil carbon reservoirs. Coal towers over oil and gas. Phase out of coal use except where the carbon is captured and stored below ground is the primary requirement for solving global warming.
Oil is used in vehicles, where it is impractical to capture the carbon. But oil is running out. To preserve our planet we must also ensure that the next mobile energy source is not obtained by squeezing oil from coal, tar shale or other fossil fuels.
Fossil fuel reservoirs are finite, which is the main reason that prices are rising. We must move beyond fossil fuels eventually. Solution of the climate problem requires that we move to carbon-free energy promptly.
Special interests have blocked transition to our renewable energy future. Instead of moving heavily into renewable energies, fossil companies choose to spread doubt about global warming, as tobacco companies discredited the smoking-cancer link. Methods are sophisticated, including disguised funding to shape school textbook discussions.
CEOs of fossil energy companies know what they are doing and are aware of long-term consequences of continued business as usual. In my opinion, these CEOs should be tried for high crimes against humanity and nature. If their campaigns continue and "succeed" in confusing the public, I anticipate testifying against relevant CEOs in future public trials.
Conviction of ExxonMobil and Peabody Coal CEOs will be no consolation, if we pass on a runaway climate to our children. Humanity would be impoverished by ravages of continually shifting shorelines and intensification of regional climate extremes. Loss of countless species would leave a more desolate planet.
If politicians remain at loggerheads, citizens must lead. We must demand a moratorium on new coal-fired power plants. We must block fossil fuel interests who aim to squeeze every last drop of oil from public lands, off-shore, and wilderness areas. Those last drops are no solution. They provide continued exorbitant profits for a short-sighted self-serving industry, but no alleviation of our addiction or long-term energy solution.
Moving from fossil fuels to clean energy is challenging, yet transformative in ways that will be welcomed. Cheap, subsidized fossil fuels engendered bad habits. We import food from halfway around the world, for example, even with healthier products available from nearby fields. Local produce would be competitive if not for fossil fuel subsidies and the fact that climate change damages and costs, due to fossil fuels, are also borne by the public.
A price on emissions that cause harm is essential. Yes, a carbon tax. Carbon tax with 100 percent dividend is needed to wean us off fossil fuel addiction. Tax and dividend allows the marketplace, not politicians, to make investment decisions.
Carbon tax on coal, oil and gas is simple, applied at the first point of sale or port of entry. The entire tax must be returned to the public, an equal amount to each adult, a half-share for children. This dividend can be deposited monthly in an individual's bank account.
Carbon tax with 100 percent dividend is non-regressive. On the contrary, you can bet that low and middle income people will find ways to limit their carbon tax and come out ahead. Profligate energy users will have to pay for their excesses.
Demand for low-carbon high-efficiency products will spur innovation, making our products more competitive on international markets. Carbon emissions will plummet as energy efficiency and renewable energies grow rapidly. Black soot, mercury and other fossil fuel emissions will decline. A brighter, cleaner future, with energy independence, is possible.
Washington likes to spend our tax money line-by-line. Swarms of high-priced lobbyists in alligator shoes help Congress decide where to spend, and in turn the lobbyists' clients provide "campaign" money.
The public must send a message to Washington. Preserve our planet, creation, for our children and grandchildren, but do not use that as an excuse for more tax-and-spend. Let this be our motto: "One hundred percent dividend or fight! No more alligator shoes!"
The next president must make a national low-loss electric grid an imperative. It will allow dispersed renewable energies to supplant fossil fuels for power generation. Technology exists for direct-current high-voltage buried transmission lines. Trunk lines can be completed in less than a decade and expanded analogous to interstate highways.
Government must also change utility regulations so that profits do not depend on selling ever more energy, but instead increase with efficiency. Building code and vehicle efficiency requirements must be improved and put on a path toward carbon neutrality.
The fossil-industry maintains its stranglehold on Washington via demagoguery, using China and other developing nations as scapegoats to rationalize inaction. In fact, we produced most of the excess carbon in the air today, and it is to our advantage as a nation to move smartly in developing ways to reduce emissions. As with the ozone problem, developing countries can be allowed limited extra time to reduce emissions. They will cooperate: they have much to lose from climate change and much to gain from clean air and reduced dependence on fossil fuels.
We must establish fair agreements with other countries. However, our own tax and dividend should start immediately. We have much to gain from it as a nation, and other countries will copy our success. If necessary, import duties on products from uncooperative countries can level the playing field, with the import tax added to the dividend pool.
Democracy works, but sometimes churns slowly. Time is short. The 2008 election is critical for the planet. If Americans turn out to pasture the most brontosaurian congressmen, if Washington adapts to address climate change, our children and grandchildren can still hold great expectations.
_____
Dr James Hansen directs the NASA Goddard Institute for Space Studies in New York City and is Adjunct Professor of Earth Sciences at Columbia University's Earth Institute. Since the mid-1970s, Dr Hansen has focused on studies and computer simulations of the Earth's climate, for the purpose of understanding the human impact on global climate. He is best known for his testimony on climate change to Congress in the 1980s that helped raise broad awareness of the global warming issue. In recent years Dr Hansen has drawn attention to the danger of passing climate tipping points, producing irreversible climate impacts that would yield a different planet from the one on which civilization developed. Dr Hansen disputes the contention, of fossil fuel interests and governments that support them, that it is an almost god-given fact that all fossil fuels must be burned with their combustion products discharged into the atmosphere. Instead Dr Hansen has outlined steps that are needed to stabilize climate, with a cleaner atmosphere and ocean, and he emphasizes the need for the public to influence government and industry policies.
Copyright (c) 2008 HuffingtonPost.com, Inc.
http://www.huffingtonpost.com/dr-james-hansen/twenty-years-later-tippin_b_108766.html
http://www.countercurrents.org/hansen250608.htm
_____ _____ _____ _____ _____ _____ _____ _____ _____ _____
Exclusive: No ice at the North Pole
Polar scientists reveal dramatic new evidence of climate change
by Steve Connor, Science Editor
Independent.co.uk (June 27 2008)
It seems unthinkable, but for the first time in human history, ice is on course to disappear entirely from the North Pole this year.
The disappearance of the Arctic sea ice, making it possible to reach the Pole sailing in a boat through open water, would be one of the most dramatic - and worrying - examples of the impact of global warming on the planet. Scientists say the ice at ninety degrees north may well have melted away by the summer.
"From the viewpoint of science, the North Pole is just another point on the globe, but symbolically it is hugely important. There is supposed to be ice at the North Pole, not open water", said Mark Serreze of the US National Snow and Ice Data Centre in Colorado.
If it happens, it raises the prospect of the Arctic nations being able to exploit the valuable oil and mineral deposits below these a bed which have until now been impossible to extract because of the thick sea ice above.
Seasoned polar scientists believe the chances of a totally ice-free North Pole this summer are greater than 50:50 because the normally thick ice formed over many years at the Pole has been blown away and replaced by huge swathes of thinner ice formed over a single year.
This one-year ice is highly vulnerable to melting during the summer months and satellite data coming in over recent weeks shows that the rate of melting is faster than last year, when there was an all-time record loss of summer sea ice at the Arctic.
"The issue is that, for the first time that I am aware of, the North Pole is covered with extensive first-year ice - ice that formed last autumn and winter. I'd say it's even-odds whether the North Pole melts out", said Dr Serreze.
Each summer the sea ice melts before reforming again during the long Arctic winter but the loss of sea ice last year was so extensive that much of the Arctic Ocean became open water, with the water-ice boundary coming just 700 miles away from the North Pole.
This meant that about seventy per cent of the sea ice present this spring was single-year ice formed over last winter. Scientists predict that at least seventy per cent of this single-year ice - and perhaps all of it - will melt completely this summer, Dr Serreze said.
"Indeed, for the Arctic as a whole, the melt season started with even more thin ice than in 2007, hence concerns that we may even beat last year's sea-ice minimum. We'll see what happens, a great deal depends on the weather patterns in July and August", he said.
Ron Lindsay, a polar scientist at the University of Washington in Seattle, agreed that much now depends on what happens to the Arctic weather in terms of wind patterns and hours of sunshine. "There's a good chance that it will all melt away at the North Pole, it's certainly feasible, but it's not guaranteed", Dr Lindsay said.
The polar regions are experiencing the most dramatic increase in average temperatures due to global warming and scientists fear that as more sea ice is lost, the darker, open ocean will absorb more heat and raise local temperatures even further. Professor Peter Wadhams of Cambridge University, who was one of the first civilian scientists to sail underneath the Arctic sea ice in a Royal Navy submarine, said that the conditions are ripe for an unprecedented melting of the ice at the North Pole.
"Last year we saw huge areas of the ocean open up, which has never been experienced before. People are expecting this to continue this year and it is likely to extend over the North Pole. It is quite likely that the North Pole will be exposed this summer - it's not happened before", Professor Wadhams said.
There are other indications that the Arctic sea ice is showing signs of breaking up. Scientists at the Nasa Goddard Space Flight Centre said that the North Water 'polynya' - an expanse of open water surrounded on all sides by ice - that normally forms near Alaska and Banks Island off the Canadian coast, is much larger than normal. Polynyas absorb heat from the sun and eat away at the edge of the sea ice.
Inuit natives living near Baffin Bay between Canada and Greenland are also reporting that the sea ice there is starting to break up much earlier than normal and that they have seen wide cracks appearing in the ice where it normally remains stable. Satellite measurements collected over nearly thirty years show a significant decline in the extent of the Arctic sea ice, which has become more rapid in recent years.
Copyright (c) independent.co.uk
http://www.independent.co.uk/environment/climate-change/exclusive-no-ice-at-the-north-pole-855406.html
Bill Totten http://www.ashisuto.co.jp/english/index.html
by James Hansen
The Huffington Post (June 23 2008)
http://www.countercurrents.org (June 25 2008)
I testified to Congress about global warming, twenty years after my June 23 1988 testimony, which alerted the public that global warming was underway. There are striking similarities between then and now, but one big difference.
Again a wide gap has developed between what is understood about global warming by the relevant scientific community and what is known by policymakers and the public. Now, as then, frank assessment of scientific data yields conclusions that are shocking to the body politic. Now, as then, I can assert that these conclusions have a certainty exceeding 99 percent.
The difference is that now we have used up all slack in the schedule for actions needed to defuse the global warming time bomb. The next president and Congress must define a course next year in which the United States exerts leadership commensurate with our responsibility for the present dangerous situation.
Otherwise it will become impractical to constrain atmospheric carbon dioxide, the greenhouse gas produced in burning fossil fuels, to a level that prevents the climate system from passing tipping points that lead to disastrous climate changes that spiral dynamically out of humanity's control.
Changes needed to preserve creation, the planet on which civilization developed, are clear. But the changes have been blocked by special interests, focused on short-term profits, who hold sway in Washington and other capitals.
I argue that a path yielding energy independence and a healthier environment is, barely, still possible. It requires a transformative change of direction in Washington in the next year.
On June 23 1988 I testified to a hearing, organized by Senator Tim Wirth of Colorado, that the Earth had entered a long-term warming trend and that human-made greenhouse gases almost surely were responsible. I noted that global warming enhanced both extremes of the water cycle, meaning stronger droughts and forest fires, on the one hand, but also heavier rains and floods.
My testimony two decades ago was greeted with skepticism. But while skepticism is the lifeblood of science, it can confuse the public. As scientists examine a topic from all perspectives, it may appear that nothing is known with confidence. But from such broad open-minded study of all data, valid conclusions can be drawn.
My conclusions in 1988 were built on a wide range of inputs from basic physics, planetary studies, observations of on-going changes, and climate models. The evidence was strong enough that I could say it was time to "stop waffling". I was sure that time would bring the scientific community to a similar consensus, as it has.
While international recognition of global warming was swift, actions have faltered. The US refused to place limits on its emissions, and developing countries such as China and India rapidly increased their emissions.
What is at stake? Warming so far, about two degrees Fahrenheit over land areas, seems almost innocuous, being less than day-to-day weather fluctuations. But more warming is already "in the pipeline", delayed only by the great inertia of the world ocean. And climate is nearing dangerous tipping points. Elements of a "perfect storm", a global cataclysm, are assembled.
Climate can reach points such that amplifying feedbacks spur large rapid changes. Arctic sea ice is a current example. Global warming initiated sea ice melt, exposing darker ocean that absorbs more sunlight, melting more ice. As a result, without any additional greenhouse gases, the Arctic soon will be ice-free in the summer.
More ominous tipping points loom. West Antarctic and Greenland ice sheets are vulnerable to even small additional warming. These two-mile-thick behemoths respond slowly at first, but if disintegration gets well under way, it will become unstoppable. Debate among scientists is only about how much sea level would rise by a given date. In my opinion, if emissions follow a business-as-usual scenario, sea level rise of at least two meters is likely within a century. Hundreds of millions of people would become refugees, and no stable shoreline would be reestablished in any time frame that humanity can conceive.
Animal and plant species are already being stressed by climate change. Species can migrate in response to movement of their climatic zone, but some species in polar and alpine regions will be pushed off the planet. As climate zones move farther and faster, climate change will become the primary cause of species extinction. The tipping point for life on the planet will occur when so many interdependent species are lost that ecosystems collapse.
The shocking conclusion, documented in a paper I have written with several of the world's leading climate experts, is that the safe level of atmospheric carbon dioxide is no more than 350 ppm (parts per million), and it may be less. Carbon dioxide amount is already 385 ppm and rising about two ppm per year. Shocking corollary: the oft-stated goal to keep global warming less than two degrees Celsius (3.6 degrees Fahrenheit) is a recipe for global disaster, not salvation.
These conclusions are based on paleoclimate data showing how the Earth responded to past levels of greenhouse gases and on observations showing how the world is responding to today's carbon dioxide amount. The consequences of continued increase of greenhouse gases extend far beyond extermination of species and future sea level rise.
Arid subtropical climate zones are expanding poleward. Already an average expansion of about 250 miles has occurred, affecting the southern United States, the Mediterranean region, Australia and southern Africa. Forest fires and drying-up of lakes will increase further unless carbon dioxide growth is halted and reversed.
Mountain glaciers are the source of fresh water for hundreds of millions of people. These glaciers are receding world-wide, in the Himalayas, Andes and Rocky Mountains. They will disappear, leaving their rivers as trickles in late summer and fall, unless the growth of carbon dioxide is reversed.
Coral reefs, the rainforest of the ocean, are home to one-third of the species in the sea. Coral reefs are under stress for several reasons, including warming of the ocean, but especially because of ocean acidification, a direct effect of added carbon dioxide. Ocean life dependent on carbonate shells and skeletons is threatened by dissolution as the ocean becomes more acid.
Such phenomena, including the instability of Arctic sea ice and the great ice sheets at today's carbon dioxide amount, show that we have already gone too far. We must draw down atmospheric carbon dioxide to preserve the planet we know. A level of no more than 350 ppm is still feasible, with the help of reforestation and improved agricultural practices, but just barely - time is running out.
The steps needed to halt carbon dioxide growth follow from the size of fossil carbon reservoirs. Coal towers over oil and gas. Phase out of coal use except where the carbon is captured and stored below ground is the primary requirement for solving global warming.
Oil is used in vehicles, where it is impractical to capture the carbon. But oil is running out. To preserve our planet we must also ensure that the next mobile energy source is not obtained by squeezing oil from coal, tar shale or other fossil fuels.
Fossil fuel reservoirs are finite, which is the main reason that prices are rising. We must move beyond fossil fuels eventually. Solution of the climate problem requires that we move to carbon-free energy promptly.
Special interests have blocked transition to our renewable energy future. Instead of moving heavily into renewable energies, fossil companies choose to spread doubt about global warming, as tobacco companies discredited the smoking-cancer link. Methods are sophisticated, including disguised funding to shape school textbook discussions.
CEOs of fossil energy companies know what they are doing and are aware of long-term consequences of continued business as usual. In my opinion, these CEOs should be tried for high crimes against humanity and nature. If their campaigns continue and "succeed" in confusing the public, I anticipate testifying against relevant CEOs in future public trials.
Conviction of ExxonMobil and Peabody Coal CEOs will be no consolation, if we pass on a runaway climate to our children. Humanity would be impoverished by ravages of continually shifting shorelines and intensification of regional climate extremes. Loss of countless species would leave a more desolate planet.
If politicians remain at loggerheads, citizens must lead. We must demand a moratorium on new coal-fired power plants. We must block fossil fuel interests who aim to squeeze every last drop of oil from public lands, off-shore, and wilderness areas. Those last drops are no solution. They provide continued exorbitant profits for a short-sighted self-serving industry, but no alleviation of our addiction or long-term energy solution.
Moving from fossil fuels to clean energy is challenging, yet transformative in ways that will be welcomed. Cheap, subsidized fossil fuels engendered bad habits. We import food from halfway around the world, for example, even with healthier products available from nearby fields. Local produce would be competitive if not for fossil fuel subsidies and the fact that climate change damages and costs, due to fossil fuels, are also borne by the public.
A price on emissions that cause harm is essential. Yes, a carbon tax. Carbon tax with 100 percent dividend is needed to wean us off fossil fuel addiction. Tax and dividend allows the marketplace, not politicians, to make investment decisions.
Carbon tax on coal, oil and gas is simple, applied at the first point of sale or port of entry. The entire tax must be returned to the public, an equal amount to each adult, a half-share for children. This dividend can be deposited monthly in an individual's bank account.
Carbon tax with 100 percent dividend is non-regressive. On the contrary, you can bet that low and middle income people will find ways to limit their carbon tax and come out ahead. Profligate energy users will have to pay for their excesses.
Demand for low-carbon high-efficiency products will spur innovation, making our products more competitive on international markets. Carbon emissions will plummet as energy efficiency and renewable energies grow rapidly. Black soot, mercury and other fossil fuel emissions will decline. A brighter, cleaner future, with energy independence, is possible.
Washington likes to spend our tax money line-by-line. Swarms of high-priced lobbyists in alligator shoes help Congress decide where to spend, and in turn the lobbyists' clients provide "campaign" money.
The public must send a message to Washington. Preserve our planet, creation, for our children and grandchildren, but do not use that as an excuse for more tax-and-spend. Let this be our motto: "One hundred percent dividend or fight! No more alligator shoes!"
The next president must make a national low-loss electric grid an imperative. It will allow dispersed renewable energies to supplant fossil fuels for power generation. Technology exists for direct-current high-voltage buried transmission lines. Trunk lines can be completed in less than a decade and expanded analogous to interstate highways.
Government must also change utility regulations so that profits do not depend on selling ever more energy, but instead increase with efficiency. Building code and vehicle efficiency requirements must be improved and put on a path toward carbon neutrality.
The fossil-industry maintains its stranglehold on Washington via demagoguery, using China and other developing nations as scapegoats to rationalize inaction. In fact, we produced most of the excess carbon in the air today, and it is to our advantage as a nation to move smartly in developing ways to reduce emissions. As with the ozone problem, developing countries can be allowed limited extra time to reduce emissions. They will cooperate: they have much to lose from climate change and much to gain from clean air and reduced dependence on fossil fuels.
We must establish fair agreements with other countries. However, our own tax and dividend should start immediately. We have much to gain from it as a nation, and other countries will copy our success. If necessary, import duties on products from uncooperative countries can level the playing field, with the import tax added to the dividend pool.
Democracy works, but sometimes churns slowly. Time is short. The 2008 election is critical for the planet. If Americans turn out to pasture the most brontosaurian congressmen, if Washington adapts to address climate change, our children and grandchildren can still hold great expectations.
_____
Dr James Hansen directs the NASA Goddard Institute for Space Studies in New York City and is Adjunct Professor of Earth Sciences at Columbia University's Earth Institute. Since the mid-1970s, Dr Hansen has focused on studies and computer simulations of the Earth's climate, for the purpose of understanding the human impact on global climate. He is best known for his testimony on climate change to Congress in the 1980s that helped raise broad awareness of the global warming issue. In recent years Dr Hansen has drawn attention to the danger of passing climate tipping points, producing irreversible climate impacts that would yield a different planet from the one on which civilization developed. Dr Hansen disputes the contention, of fossil fuel interests and governments that support them, that it is an almost god-given fact that all fossil fuels must be burned with their combustion products discharged into the atmosphere. Instead Dr Hansen has outlined steps that are needed to stabilize climate, with a cleaner atmosphere and ocean, and he emphasizes the need for the public to influence government and industry policies.
Copyright (c) 2008 HuffingtonPost.com, Inc.
http://www.huffingtonpost.com/dr-james-hansen/twenty-years-later-tippin_b_108766.html
http://www.countercurrents.org/hansen250608.htm
_____ _____ _____ _____ _____ _____ _____ _____ _____ _____
Exclusive: No ice at the North Pole
Polar scientists reveal dramatic new evidence of climate change
by Steve Connor, Science Editor
Independent.co.uk (June 27 2008)
It seems unthinkable, but for the first time in human history, ice is on course to disappear entirely from the North Pole this year.
The disappearance of the Arctic sea ice, making it possible to reach the Pole sailing in a boat through open water, would be one of the most dramatic - and worrying - examples of the impact of global warming on the planet. Scientists say the ice at ninety degrees north may well have melted away by the summer.
"From the viewpoint of science, the North Pole is just another point on the globe, but symbolically it is hugely important. There is supposed to be ice at the North Pole, not open water", said Mark Serreze of the US National Snow and Ice Data Centre in Colorado.
If it happens, it raises the prospect of the Arctic nations being able to exploit the valuable oil and mineral deposits below these a bed which have until now been impossible to extract because of the thick sea ice above.
Seasoned polar scientists believe the chances of a totally ice-free North Pole this summer are greater than 50:50 because the normally thick ice formed over many years at the Pole has been blown away and replaced by huge swathes of thinner ice formed over a single year.
This one-year ice is highly vulnerable to melting during the summer months and satellite data coming in over recent weeks shows that the rate of melting is faster than last year, when there was an all-time record loss of summer sea ice at the Arctic.
"The issue is that, for the first time that I am aware of, the North Pole is covered with extensive first-year ice - ice that formed last autumn and winter. I'd say it's even-odds whether the North Pole melts out", said Dr Serreze.
Each summer the sea ice melts before reforming again during the long Arctic winter but the loss of sea ice last year was so extensive that much of the Arctic Ocean became open water, with the water-ice boundary coming just 700 miles away from the North Pole.
This meant that about seventy per cent of the sea ice present this spring was single-year ice formed over last winter. Scientists predict that at least seventy per cent of this single-year ice - and perhaps all of it - will melt completely this summer, Dr Serreze said.
"Indeed, for the Arctic as a whole, the melt season started with even more thin ice than in 2007, hence concerns that we may even beat last year's sea-ice minimum. We'll see what happens, a great deal depends on the weather patterns in July and August", he said.
Ron Lindsay, a polar scientist at the University of Washington in Seattle, agreed that much now depends on what happens to the Arctic weather in terms of wind patterns and hours of sunshine. "There's a good chance that it will all melt away at the North Pole, it's certainly feasible, but it's not guaranteed", Dr Lindsay said.
The polar regions are experiencing the most dramatic increase in average temperatures due to global warming and scientists fear that as more sea ice is lost, the darker, open ocean will absorb more heat and raise local temperatures even further. Professor Peter Wadhams of Cambridge University, who was one of the first civilian scientists to sail underneath the Arctic sea ice in a Royal Navy submarine, said that the conditions are ripe for an unprecedented melting of the ice at the North Pole.
"Last year we saw huge areas of the ocean open up, which has never been experienced before. People are expecting this to continue this year and it is likely to extend over the North Pole. It is quite likely that the North Pole will be exposed this summer - it's not happened before", Professor Wadhams said.
There are other indications that the Arctic sea ice is showing signs of breaking up. Scientists at the Nasa Goddard Space Flight Centre said that the North Water 'polynya' - an expanse of open water surrounded on all sides by ice - that normally forms near Alaska and Banks Island off the Canadian coast, is much larger than normal. Polynyas absorb heat from the sun and eat away at the edge of the sea ice.
Inuit natives living near Baffin Bay between Canada and Greenland are also reporting that the sea ice there is starting to break up much earlier than normal and that they have seen wide cracks appearing in the ice where it normally remains stable. Satellite measurements collected over nearly thirty years show a significant decline in the extent of the Arctic sea ice, which has become more rapid in recent years.
Copyright (c) independent.co.uk
http://www.independent.co.uk/environment/climate-change/exclusive-no-ice-at-the-north-pole-855406.html
Bill Totten http://www.ashisuto.co.jp/english/index.html
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