How global warming is changing Animal kingdom

Scientists take note of shifts in animal behavior

The planet is warming, humans are mostly to blame and plants and animals are going to dramatic lengths to cope. That's the consensus of a number of recent studies that used wildlife to gauge the extent of global warming and its effects.

While the topic of climate change is contentious - including whether the planet is actually heating up - a growing number of documented shifts in traits and behaviors in the wild kingdom is leading many scientists to conclude the world is changing in unnatural ways.

Marmots end their hibernations about three weeks earlier now compared to 30 years ago. Polar bears today are thinner and less healthy than those of 20 years ago. Many fish species are moving northward in search of cooler waters. A fruitfly gene normally associated with hot, dry conditions has spread to populations living in traditionally cooler southern regions.

While We Argue...

Over the past century, Earth's average temperature has risen by about 1 degree Fahrenheit and many scientists believe greenhouse gases and carbon dioxide emissions from human activities are to blame. Left unattended, they warn, temperatures may rise by an additional 2-10 degrees by the end of the century. In the leading computer models, it follows that polar ice will melt and seas would rise drastically, threatening coastal communities around the globe.

A handful of scientists dispute the data. Others say humans aren't to blame.

Terry Root, an environmental science and policy professor at Stanford University, says that as humans argue about thermometer readings, animals are providing evidence that should be figured in to scientific and political decisions.

Animals are "just reacting to what's going on out there," Root says. "And if their behavior is very similar to what we expect with what's going on with global warming - if they're shifting and they're moving, if they're changing their breeding time by 5 days in 10 years - we can use that information to support what the thermometers are also showing."

Climate change can occur naturally, but what worries many scientists the most - and the reason why they don't think this is part of a natural cycle - is the rapid rate at which the current changes are happening - changes that are being reflected in the responses of wildlife.

In a 2003 study published in the journal Nature, Root and her colleagues analyzed numerous studies involving wild plant and animals for changes due to global warming. Out of the nearly 1,500 species examined, the researchers found that about 1,200 exhibited temperature-related changes consistent with what scientists would expect if they were being affected by global warming.

The authors highlighted four possible ways that species might respond to rising temperatures, all of which have been documented by other studies and researchers.

Divide and Destroy

The first is for species to migrate northward or move to higher elevations. The ubiquitous presence of humans, however, is making this option difficult for some species.

"The thing that is very, very different from prehistoric times is that there are now K-Mart parking lots these species have to cross as they try to move north to get away from the heat down south," Root told LiveScience.

As a result, species that can't adapt to urban or agricultural environments become isolated, their lines of retreat cut off.

In a study published last year in the journal PLoS Biology, Elizabeth Hadly, a biologist at Stanford University, examined fossil records from past warming periods and concluded that global warming can reduce genetic diversity by affecting the connections between species populations.

The best way to ensure species survival is to have large, interconnected populations that are genetically diverse, Hadly explained in an email interview.

This means that even if the genetic diversity of a species as a whole is high, if the individuals are scattered and prevented from interbreeding, they can become just as vulnerable to disease and external threats as a species with a small population and low genetic diversity. Like the military strategy of divide-and-conquer, a group that together might have had the resources to withstand an assault can be picked off one by one if split up.

Connections among individuals within a species aren't the only things that can be disrupted: global warming can also threaten the ties that bind members of different species to one another.

Many biologists, including Darwin, once believed that species responded to temperature changes as a group, thus preserving their relationships to one another. But scientists are finding that this is often not the case.

Instead, different species respond to environmental stressors in different ways, and this can lead to what Root calls the "tearing apart of communities."

Intricate Connections

The second prediction was that the timing of natural events like flowering, migration, and egg-laying could shift. Ecosystems are intricately connected webs, and even if a species doesn't rely on temperature and daylight cues to trigger certain behaviors, it may interact with other species that do.

"Thousands of years of co-evolution could easily be disrupted," Root says.

Third, the body size and behaviors of species may change in response to rising temperatures. For example, scientists believe that as a general rule, bodies become smaller in response to general warming and larger with cooling.

A 2003 study led by Philip Gingerich, a geological sciences professor at the University of Michigan, looked at horse fossils from a warming period that occurred 55 million years ago. They found that as temperatures rose, the fossils shrank, from the size a small dog to a house cat. The researchers believed the dwarfing might have resulted from the horses eating plants whose tissues were low in protein but high in toxic compounds - plants that flourished in the carbon dioxide-rich environment of the time.

Finally, species can undergo genetic changes. This last prediction has been documented in at least two species, the red squirrel and the fruitfly Drosophila.

Business as Usual?

Not all scientists are convinced humans have anything to do with climate change or the shifts seen in the animal world.

Michael Patrick, an environmental science professor at the University of Virginia, believes the current warming is part of a natural cycle.

"It's what you'd expect," Patrick told LiveScience. "It's not all a result of human induced climate change. Half of it is at best, probably less than half."

Even if humans are causing global warming, Patrick said, there is little we can do to change it. "If it is an issue, it is one that we will have to adapt to."

Patrick believes the wildlife changes are likewise natural.

"With all due respect, you would expect to see some slight changes in the distribution of plants and animals as the planet warms - or as the planet cools for that matter," Patrick said. "It's hardly newsworthy."

If anything, most species would benefit from an earlier spring, and focusing on global warming is a harmful distraction from more serious problems afflicting wildlife, Patrick says. "If you asked me which one we should worry about more - changes in climate or human-caused changes in habitat - I would say that the latter is much more important."

"Overall climate will change quite a bit," Patrick said. "However, if you change characteristics of the surface - if you turn forest into farmland - that will have more severe effects on wildlife than merely changing the temperature a degree or two."

Stressful Future

Ecosystems and wildlife aren't the only things that increasing temperatures will affect.

"Global warming is going to be a big stress to all animals, including Homo sapiens," said Root.

A recent report issued by the Pew Center for Global Climate Change, a Virginia-based nonprofit organization, warned that rising temperatures could exacerbate health risks such as asthma for the elderly, the infirm and the poor, and especially for those in poor countries.

Even if all pollution were stopped today, the climate will warm at least another degree by the year 2100 and seas will rise 4 inches (11 centimeters), according to one recent study. Another report says warming is unstoppable through the year 2400. Despite the dire warnings, many scientists believe it may not be too late to reverse the trend.

The Pew report suggests creating transitional habitats that link natural areas as a way to help migrating species. Also, alleviating other environmental stressors like habitat destruction could help reduce their combined effects with global warming.

Root is encouraged by the fact that many cities are following higher environmental standards, even if state and national governments are dragging their feet.

In the end, she believes, it will be the relatively small things that people do that will have the biggest impact: "Hummer sales, thank heaven, are dropping since gas prices have gone up, and hybrid [car] sales have gone up. It's that type of stuff."

Extinction

Polar bear 'extinct within 100 years'

The polar bear could be driven to extinction by global warming within 100 years, warns an ecology expert.

The animal, which relies on sea ice to catch seals, is already starting to suffer the effects of climate changes in areas such as Hudson Bay in Canada.

Scientists say Arctic sea ice is melting at a rate of up to 9% per decade. Arctic summers could be ice-free by mid-century. Dr Andrew Derocher, of the University of Alberta, Edmonton, has used the data to assess the impact on the Arctic's top predator.

Top carnivore

He believes the polar bear could disappear in the wild by the end of the century unless the pace of global warming slows.

He told "Polar bears are a species whose whole life history is dependent on having sea ice.

"As the sea ice changes in distribution and pattern we can expect this to have fundamental changes on the ecology of polar bears.

"As the sea ice disappears, so will the polar bears."

Polar bears are uniquely adapted to survival in the Arctic. They are the world's largest land predator, feeding mainly on seals.

They use the sea ice as a floating platform to catch prey and they travel across it on their way to their dens.

British polar expert Dr Peter Wadhams of the University of Cambridge says the bear faces a gloomy future unless it is able to change its habits.

"It could be that a polar bear could adapt to a new habitat and adopt habits like the brown bear in Alaska which hunts salmon in streams and other small animals on land," he said.

Fragile ecology

Scientists believe that Ursus maritimus, the "sea bear", evolved about 200,000 years ago from brown bear ancestors.

Whether it can "change its spots" and behave more like a brown bear is another matter.

Lynn Rosentrater, climate scientist in the WWF International Arctic Programme, thinks it unlikely.

There have been cases of polar bears scavenging in bins for food in summer, she said, but the animals need seal fat to get through the winter.

"In the absence of sea ice the whole basis of polar bear ecology ceases to exist," she explained. Polar bears are currently found in Arctic regions of Alaska, Canada, Russia, Greenland and Norway.

Populations in southern limits such as Hudson Bay are at most risk of dying out.

Bears stand most chance of surviving, in isolated groups, in the western Arctic or the Canadian archipelago.

Polar Bears in recent decades

What has been happening to polar bears in recent decades?

Scott L. Schliebe
Polar Bear Project Leader
U.S. Fish and Wildlife Service/MMM
Anchorage, AK

Polar bears have long captured the attention of the general public but probably at no time in the past have they been more in the forefront of the public's imagination than today. Today's heightened interest in polar bears may be due in part to an enhanced understanding of the ecology of polar bears, their environment, and an increased interest in Arctic issues brought on by concerns for climate change. Results of years of research and studies are now available to an interested public, and efforts to communicate this information to the public has been more effective in recent years than in the past. As a result the current public is generally well-informed and educated regarding the ecology of polar bears. This public, unlike previous publics, has a variety of communication tools that enable it to interact and communicate more effectively with researchers and managers.

What have we learned? We now know that polar bears are not a single large homogeneous population that roams throughout the Arctic. Instead groups of polar bears referred to as stocks or populations, are distributed throughout the Arctic. Research begun in the late 1960s and continuing today also provides a thorough backdrop of information on population demographics, systematically analyzed data on population boundaries, population movements, population size, reproductive and survival parameters, and other useful information about biological, physiological, and ecological aspects of polar bears.

We also realize that polar bears do not occur in large numbers; their ability to replace individuals in the population is very limited and population growth is extremely slow; they are long-lived creatures, which helps to offset the low reproductive potential; their populations fluctuate in response to natural factors such as climate and prey availability; and, populations can also be impacted by humans through factors such as hunting, oil spills, shipping, and other activities. We also realize that the level of human presence and activity in the Arctic continues to build. As a result the potential for humans to impact polar bears has never been greater than today.

Technologically, researchers have been blessed in the last 30 years. Advances in satellite telemetry allowed researchers to follow individual bears over time and greatly enhanced our knowledge of movements and population bounds. Infrared thermal sensory equipment is providing promise in detecting polar bear dens beneath the snow. Extended time-series of data now available for some populations documents trends that were previously not apparent. Improvements in aircraft and vessel transportation have provided access to a larger portion of the range of polar bears than was previously accessible. Finally, technologic advances have allowed for multi-disciplinary Arctic research, which is in many cases supported by polar-class icebreakers. All of these advances plus greater understanding of population dynamics and population modeling now allow for greater precision in making management decisions and a better understanding of risks and consequences of management actions.

In the past, one of the greatest saving graces for polar bear populations was the fact that their habitat was relatively pristine and secure from alteration. In fact a very large portion of the high arctic was void of any human presence. Hence at that time the greatest concern for polar bear populations were over harvest and human development that was occurring at the fringes of the range of polar bears.

Polar bears and their prey have evolved to living in the extreme conditions of the Arctic. Polar bears and seals are dependent on sea-ice for foraging, resting, and reproduction. The Arctic ecosystem was shaped by climate and continues to be driven today by climate. Polar bears and ice seals, primarily ringed seals, serve as key indicators of the effects of climate change on the Arctic environment. Today, polar bear populations are facing threats previously unprecedented during recorded history in the Arctic. Recent climate change scenarios based upon modeling of climate trend data predict that the Arctic region will experience major changes in the upcoming decades. On the most drastic end of the spectrum one model predicts that the Arctic basin may be void of ice within 50 years. Other models have shown that ice thickness has decreased by 40% during the past 30 years and the average annual extent of ice coverage in the polar region has diminished substantially, with an average annual reduction of over 1 million square kilometers.

While the ultimate or progressively evolving effects of climatic change on polar bear populations is not certain, we do recognize that even minor climate changes could likely have a profound effect on polar bears. The following is from the IUCN/Species Survival Commission, Polar Bear Specialist Group (PBSG) web site and in summary indicates the following:

Climate changes on prey species will have a negative effect on polar bears

• increased snow can result in reduced success in successfully entering seal birth lairs



• decreased snow or increased seasonal rain patterns could effect seal pupping by not providing adequate snow for construction of birth lairs or if rain fall by collapsing birth lairs thus reducing seal productivity



• prey reductions could effect polar bear condition and ultimately cub production and survival

Changes that alter the period of ice coverage could affect distribution and impact polar bears

• bears may spend greater amounts of time on land


• extended use of terrestrial areas would ultimately effect physical condition of bears when forced to rely on fat stores


• decreased physical condition could effect production and survival


• bears using deteriorating pack ice may experience increased energetic costs associated with movements and swimming

Denning could be impacted by unusual warm spells

• access to high quality denning areas may be limited or restricted
  
• use of less desirable denning habitat could have impacts on reproduction and survival
  
• rain or warming could directly cause snow dens to collapse or be opened to ambient conditions


• loss of thermal insulative properties in opened dens could affect litter survival

As a case in point, in Western Hudson Bay researchers have collected demographic information on polar bears since 1981. Over this time frame and location the sea ice breakup has been occurring earlier. The earlier breakup has been related to the poorer condition of polar bears and there is a correlation between the earlier breakup and a decadal scale pattern of warming air temperatures during the spring between 1950 and 1990. It appears that earlier breakup caused by warmer temperatures has resulted in declines in physical and reproductive parameters of polar bears in this area. This is the only study to date to demonstrate the effects of changed environment resulting from climate changes, and a corresponding effect on polar bears. Climate change is not uniform in all areas of the Arctic, however. Since Hudson Bay is located at the southern most extent of the range of polar bears, findings here may be a forewarning of changes to come in future years for other areas of the Arctic. Clearly, climate change and its effect on sea ice and polar bears should be closely monitored in future years.

Environmental contaminants in the form of persistent organic pollutants (POPs) pose an additional area of increased concern for polar bears. Recent documentation of baseline contaminant levels in the circumpolar environment and in key species has dramatically expanded the knowledge of regional presence and levels of these pollutants over the past 10 years. Polar bears, as an apical predator that tends to amplify the accumulation organochlorines compounds, are a perfect candidate for studies in evaluating trends. We now know that polar bears inhabiting certain areas of the Arctic exhibit elevated levels of organochlorines, particularly PCB's (poly chlorinated biphenyls) while populations inhabiting other areas have lower levels. Laboratory experiments involving elevated levels of organochlorines have been associated with a range of effects including neurological, reproductive, and immunological changes. Studies are continuing to evaluate the effect of persistent organic pollutants on essential life functions of polar bears and other marine animals with an emphasis on evaluating immune and hormonal systems.

International involvement in polar bear conservation dates back to 1965 when scientists from Canada, Norway, Denmark, USSR, and the United States met in Fairbanks to discuss polar bear conservation due to widespread concern that populations were being over harvested. Until this time there had been very little management of polar bears in the Arctic and no coordinated effort among arctic countries. Harvest rates were rising rapidly in most areas except Russia which had enacted a ban on hunting in 1956. The Fairbanks meeting resulted in the formation of the IUCN/SSC Polar Bear Specialist Group (PBSG) whose mission was to coordinate polar bear research and management programs on an international basis and to exchange information on each country's programs.

Members of the PBSG and the countries they represent developed and negotiated the International Agreement on the Conservation of Polar Bears (Agreement), which was signed in Oslo, Norway in May, 1973. Among other conditions the Parties agreed through Article VII to "conduct national research programs on polar bears, particularly research relating to the conservation and management of the species. They shall, as appropriate, coordinate such research with the research carried out by other Parties, consult with other Parties on management of migrating polar bear populations, and exchange information on research and management programs, research results, and data on bears taken." The PBSG meets every three to five years with a goal of advancing the principles of the Agreement. The most recent meeting was held June 2001 in Nuuk, Greenland. The proceedings of the working group meetings are published in the IUCN series.

Highlights of recent activities include: conducting ecotoxological studies to evaluate potential effects on polar bear immune and hormone systems in the Svalsbard Island complex; continuing efforts to refine population boundaries and better understand sustainable harvest levels or the effects of harvests on populations; evaluating new techniques to conduct aerial population surveys; evaluating the relationship between bears, seals, and sea ice conditions; population genetics studies; and research to evaluate the effectiveness of thermal sensory technology to detect polar bear dens beneath snow.

Gore Shares Peace Prize for Climate Change Work

By WALTER GIBBS and SARAH LYALL

Published: October 13, 2007

OSLO, Oct. 12 — Former Vice President Al Gore, who emerged from his loss in the muddled 2000 presidential election to devote himself to his passion as an environmental crusader, was awarded the 2007 Nobel Peace Prize on Friday, sharing it with the Intergovernmental Panel on Climate Change, a United Nation network of scientists.

The Norwegian Nobel Committee praised both "for their efforts to build up and disseminate greater knowledge about man-made climate change."

The prize is a vindication for Mr. Gore, whose cautionary film about the consequences of climate change, "An Inconvenient Truth," won the 2007 Academy Award for best documentary, even as conservatives in the United States denounced it as alarmist and exaggerated.

"I will accept this award on behalf of all the people that have been working so long and so hard to try to get the message out about this planetary emergency," Mr. Gore said Friday in Palo Alto, Calif., standing with his wife, Tipper, and four members of the United Nations climate panel. "I’m going back to work right now," he said.

The award was also a validation for the United Nations panel, which in its early days was vilified by those who disputed the scientific case for a human role in climate change. In New Delhi, the Indian climatologist who heads the panel, Rajendra K. Pachauri, said that science had won out over skepticism.

Mr. Gore, a vociferous opponent of the Bush administration on a range of issues, including the Iraq war, is the second Democratic politician to win the peace prize this decade. Former President Jimmy Carter won in 2002.

Mr. Carter, himself a critic of Mr. Bush, was 78 when he won the prize. But Mr. Gore is just 59 and an active presence in American politics, if only as a large thorn in Mr. Bush’s side — and in the side of Democrats worried that he might challenge them for the 2008 Democratic presidential nomination. Mr. Gore, who lost the 2000 election to Mr. Bush, has regularly said that he will not run for president again. But Friday’s announcement touched off renewed interest in his plans.

Tony Fratto, a White House spokesman, did not go overboard in his praise. "Of course we’re happy for Vice President Gore and the I.P.C.C. for receiving this recognition," he said.

In Oslo, Ole Danbolt Mjoes, chairman of the peace committee, was asked whether the award could be seen as criticism of the Bush administration, which did not subscribe to the Kyoto treaty to cap greenhouse gases. He replied that the Nobel was not meant to be a "kick in the leg to anyone" — the Norwegian expression for "kick in the teeth."

"We would encourage all countries, including the big countries, and challenge them to think again and to say what they can do to conquer global warming," Dr. Mjoes said in Oslo.

The four other members of the peace committee generally refuse to comment on the thinking behind the award, which in recent years has moved toward issues at a degree of remove from armed conflict, like social justice, poverty remediation and environmentalism. But in a telephone interview, Berge Furre, one of the four, said, "I hope this will have an effect on the attitudes of Americans as well as people in other countries."

In its formal citation, the Nobel committee called Mr. Gore "probably the single individual who has done most to create greater worldwide understanding of the measures that need to be adopted." It praised the United Nations panel, which is made up of 2,000 scientists and is considered the world’s leading authority on climate change, for creating "an ever-broader informed consensus about the connection between human activities and global warming."

While the world’s major environmental groups all praised Mr. Gore for his role in raising public awareness, they praised the panel for, in the words of Greenpeace International, "meticulous scientific work."

The two approaches both play a part, scientists said Friday. "The noble prize is honoring the science and the publicity, and they’re necessarily different," said Spencer R. Weart, a historian at the American Institute of Physics.

Mr. Gore, who announced he would give his portion of the $1.5 million prize money to the nonprofit organization he founded last year, the Alliance for Climate Protection, said he was honored to share the prize with the panel, calling it "the world’s pre-eminent scientific body devoted to improving our understanding of the climate crisis."

Mr. Pachauri said, "The message that it sends is that the Nobel Prize committee realized the value of knowledge in tackling the problem of climate change." He said the award was an acknowledgment of the panel’s "impartial and objective assessment of climate change."

The climate panel, established in 1988, has issued a series of increasingly grim reports in the last two decades assessing issues surrounding climate change. It is expected to issue another report in the next few months, before the United Nations Climate Change Conference in Indonesia on Dec. 3. Some 180 countries are scheduled to begin negotiations there on a successor to the Kyoto Protocol, which expires in 2012.

Hans Joachim Schellnhuber, the climate adviser to Chancellor Angela Merkel of Germany and a leading contributor to the United Nations panel’s reports, said they were the result of "a painstaking process of self-interrogation."

The committee acts at "about the highest level of complexity you can manage in such a scientific assessment," Dr. Schellnhuber said in a telephone interview from Milan.

For a scientist, he said, taking part on the climate change panel entails considerable sacrifices. "It drives you absolutely crazy," Dr. Schellnhuber said. "You fly to distant places; you stay up all night negotiating; you listen to hundreds of sometimes silly interventions. You go through so many mundane things to produce the big picture."

The Nobel prizes are meant to be apolitical, and are awarded independently of one another. (The peace prize is awarded in Oslo, while the others are awarded by various academies in Sweden.) But a number of recent winners have expressed their opposition to Bush administration policies.

The 2005 literature winner, the British playwright Harold pinter, turned his Nobel address into a blistering indictment of American foreign policy since the Second World War. A co-winner of the peace prize that year, Mohamed ElBaradei, the director of the International Atomic Energy Agency, made no secret of his opposition to the American invasion of Iraq and has angered the Bush administration by his measured methods for trying to rein in nuclear proliferation, particularly in Iran.

In its citation on Friday, the Norwegian Nobel Committee said the United Nations panel and Mr. Gore had focused "on the processes and decisions that appear to be necessary to protect the world’s future climate, and thereby reduce the future threat to the security of mankind."

It concluded, "Action is necessary now, before climate change moves beyond man’s control."

Walter Gibbs reported from Oslo, and Sarah Lyall from London. Reporting was contributed by Jesse McKinley from Palo Alto, Calif., Somini Sengupta from New Delhi, Mark Landler from Frankfurt, David Rampe from Paris, and Andrew C. Revkin from New York.

New York times report on the climate change

June 23, 2008
1988-2008: Climate Then and Now


By

Andrew c. Revkin
Global warming has felt like breaking news a few times in recent years. But the first big pulse of coverage and public attention came in 1988, when the Amazon Rainforest and Yellowstone were ablaze, a searing drought had farmers kicking dusty fields in frustration, and global temperatures had seen enough of a rise that a NASA climate expert, James Hansen, asserted before a Senate panel that statistics showed "the greenhouse effect has been detected and is changing our climate now."
I thought it might be worth inviting you all to read and "annotate" (as we’ve done with a couple of climate speeches and polar bear decision recently) my cover story for Discover Magazine, reported through that hot year and published in the October 1988 edition. I asked the current management there if they’d post the original article. They liked the idea, but the article was so old that it wasn’t

even available in electronic form, so they had to type it up. Here’s the story, Melissa Lafsky of the magazine also did a brief e-mail interview with me, which is on their Reality base blog.

I’ll start by posting some relevant sections below and offering some reflections on how the story has stood the test of time. I’d enjoy seeing your reactions, pro or con.


I was not at the Senate Energy Committee hearing when Dr. Hansen testified. But I had been focused on climate and humans since 1984, when I began reporting what would end up being a long cover story for Science Digest magazine assessing nuclear winter, kind of the inverse potential human impact on climate (global cooling from a pall of smoke rising from incinerated cities). I went to Toronto one week after Dr. Hansen’s testimony to report from the first international "Conference on changing Atmosphere" — one of the seminal meetings building momentum toward the first report of the newborn InterGovernmental panel on climate change.


Nuclear winter, as I wrote in 1985, was more nuanced than the initial dramatic concept, morphing from a Page One post-apocalyptic apocalypse into a more subtle phenomenon, labeled "nuclear autumn" by Stephen H. Schneider. What is distinct about global warming is that the basics of 100-year-old theory have stood the test of time (more CO2 = warming world = less ice + higher seas and lots of climate change). Let’s dive into my old story to see what has, and has not, changed.
After an opening section leading off with Dr. Hansen’s testimony:


Until this year, despite dire warnings from climatologists, the greenhouse effect has seemed somehow academic and far off. The idea behind it is simple: gases accumulating in the atmosphere as by-products of human industry and agriculture — carbon dioxide, mostly, but also methane, nitrous oxide, ozone, and chlorofluorocarbon — let in the sun’s warming rays but don’t let excess heat escape. As a result, mean global temperature has probably been rising for decades. But the rise has been so gradual that it has been masked by the much greater, and ordinary, year-to-year swings in world temperature.
In my
YouTube interview with Dr. Hansen, he discusses how the public remains attuned mainly to anomalies on short time scales — cold or warm — and misses the point that it is the long-term trend that he and other experts say will transform the planet, but at a pace invisible day to day.
Not anymore, said Hansen. The 1980s have already seen the four hottest years on record, and 1988 is almost certain to be hotter still. Moreover, the seasonal, regional, and atmospheric patterns of rising temperatures — greater warming in winters than summers, greater warming at high latitudes than near the equator, and a cooling in the stratosphere while the lower atmosphere is warmer — jibe with what computer models predict should happen with greenhouse heating. And the warming comes at a time when, by rights, Earth should actually be cooler than normal. The sun’s radiance has dropped slightly since the 1970s, and dust thrown up by recent volcanic eruptions, especially that of Mexico’s El Chichon in 1982, should be keeping some sunlight from reaching the planet.
What’s important here, and remains important, scientists say, is how the patterns of atmospheric and climatic change reveal the most about the involvement of greenhouse gases, not simply the change in global temperature.

Even though most climatologists think Hansen’s claims are premature, they agree that warming is on the way. Carbon dioxide levels are 25 percent higher now than they were in 1860, and the atmosphere’s burden of greenhouse gases is expected to keep growing. By the middle of the next century the resulting warming could boost global mean temperatures from three to nine degrees Fahrenheit. That doesn’t sound like much, but it equals the temperature rise since the end of the last ice age, and the consequences could be devastating. Weather patterns could shift, bringing drought to once fertile areas and heavy rains to fragile deserts that cannot handle them. As runoff from melting glaciers increases and warming seawater expands, sea level could rise as much as six feet, inundating low-lying coastal areas and islands. There would be dramatic disruptions of agriculture, water resources, fisheries, coastal activity, and energy use.


The range of possible warming from a particular rise in greenhouse gas concentrations is only a little narrower than it was back then. Again, this remains a risk-management challenge. As Dr. Hansen says in the video interview, climate is not something that we will "fix."


"Average climate will certainly get warmer," says Roger Revelle, an oceanographer and climatologist at the University of California at San Diego. "But what’s more serious is how many more hurricanes we’ll have, how many more droughts we’ll have, how many days above one hundred degrees." By Hansen’s reckoning, where Washington now averages one day a year over 100 degrees, it will average 12 such scorchers annually by the middle of the next century.
At the time, the basic notion that warmer seawater would fuel hurricanes was young and untested. Most scientists projecting many more, and stronger storms, including Kerry Emanuel (quoted farther down in my 1988 story), have since shifted to more nuanced projections. Enough time has passed that Dr. Emanuel and some other researchers say intensification has already been seen. But the hurricane-climate connection remains an idea its formative stages.


Comparable climate shifts have happened before, but over tens of centuries, not tens of years. The unprecedented rapid change could accelerate the already high rate of species extinction as plants and animals fail to adapt quickly enough. For the first time in history humans are affecting the ecological balance of not just a region but the entire world, all at once. "We’re altering the environment far faster than we can possibly predict the consequences," says Stephen Schneider, a climate modeler at the National Center for Atmospheric Research in Boulder, Colorado. "This is bound to lead to some surprises."


The situation then remains similar today in that the worst-case outcomes from a greenhouse-warmed world are clearly possible, but with the probability hard to nail down. This is one reason the policy debate, essentially over how much to invest in a climate insurance policy, remains turbulent.
A few themes that are central to climate discussions now were not part of the global warming story in 1988 — most notably the concept of thresholds and nonlinear "tipping points." The evidence that climate can shift abruptly had not yet emerged from ice cores in Greenland. All the curves looking forward were smooth.
The rising role of developing countries was also described in the story, along with the looming challenge posed by the rise of China as an economic, and climatic, force:


In the end, the greatest obstacle facing those who are trying to slow the output of greenhouse gases is the fundamental and pervasive nature of the human activities that are causing the problem: deforestation, industrialization, energy production. As populations boom, productivity must keep up. And even as the developed nations of the world cut back on fossil fuel use, there will be no justifiable way to prevent the Third World from expanding its use of coal and oil. How can the developed countries expect that China, for example, which has plans to double its coal production in the next 15 years in order to spur development, will be willing or even able to change course?
Overall, the story captured the same situation that scientists are still trying to describe now: a world poised for momentous changes that would be hard to reverse; the need for adaptation to inevitable changes and changes in energy choices to cut the chances of utter calamity; and the need to act in the face of uncertainty.


The piece culminated with a quote from Michael McElroy, a climate expert at Harvard, speaking at the Toronto climate conference. It could still be delivered today.
Michael McElroy concluded, "If we choose to take on this challenge, it appears that we can slow the rate of change substantially, giving us time to develop mechanisms so that the cost to society and the damage to ecosystems can be minimized. We could alternatively close our eyes, hope for the best, and pay the cost when the bill comes due."


Again, I’d love to hear your thoughts on particular sections of the story. Point them out in your comment and I’ll post the relevant paragraph and link to your contribution.

UNEP`S research on climate change

Warmer World May Mean Less Fish

Global Warming Adding to Pollution and Over-Harvesting Impacts on the World's Key Fishing Grounds Says New UNEP - "In Dead Water" - Report

Monaco/Nairobi, 22 February 2008 -

Climate change is emerging as the latest threat to the world's dwindling fish stocks a new report by the UN Environment Programme (UNEP) suggests.
At least three quarters of the globe's key fishing grounds may become seriously impacted by changes in circulation as a result of the ocean's natural pumping systems fading and falling they suggest.

These natural pumps, dotted at sites across the world including the Arctic and the Mediterranean, bring nutrients to fisheries and keep them healthy by flushing out wastes and pollution.
The impacts of rising emissions on the marine world are unlikely to end there. Higher sea surface temperatures over the coming decades threaten to bleach and kill up to 80 per cent of the globe's coral reefs-major tourist attractions, natural sea defences and also nurseries for fish.

Meanwhile there is growing concern that carbon dioxide emissions will increase the acidity of seas and oceans. This in turn may impact calcium and shell-forming marine life including corals but also tiny ones such as planktonic organisms at the base of the food chain.

The findings come in a new rapid response report entitled "In Dead Water" which has for the first time mapped the multiple impacts of pollution; alien infestations; over-exploitation and climate change on the seas and oceans.
"The worst concentration of cumulative impacts of climate change with existing pressures of over-harvest, bottom trawling, invasive species infestations, coastal development and pollution appear to be concentrated in 10-15 per cent of the oceans," says the report.

This 10-15 per cent of the oceans is far higher than had previously been supposed and is "concurrent with today's most important fishing grounds" including the estimated 7.5 per cent deemed to be the most economically valuable fishing areas of the world, it adds.

The report, the work of UNEP scientists in collaboration with universities and institutes in Europe and the United States, was launched today during UNEP's Governing Council/Global Ministerial Environment Forum taking place in Monaco.

It is the largest gathering of environment ministers since the climate convention conference in Indonesia just over two months ago where governments agreed the Bali Road Map aimed at delivering a deep and decisive climate regime for post 2012.

Achim Steiner, UN Under-Secretary General and UNEP Executive Director, said:" The theme of the Governing Council is 'Mobilizing Finance for the Climate Challenge for trillions of dollars can flow into climate-friendly energies and technologies if government's can provide the right kind of enabling market mechanisms and fiscal incentives".

"It is sometimes important to remind ourselves why we need to accelerate these transformations towards a Green Economy. In Dead Water has uniquely mapped the impact of several damaging and persistent stresses on fisheries. It also lays on top of these the likely impacts of climate change from dramatic alternations in ocean circulation affecting perhaps a three quarter of key fishing grounds up to the emerging concern of ocean acidification," said Mr Steiner.

"Climate change threatens coastal infrastructure, food and water supplies and the health of people across the world. It is clear from this report and others that it will add significantly to pressures on fish stocks. This is as much a development and economic issue as it is an environmental one. Millions of people including many in developing countries derive their livelihoods from fishing while around 2.6 billion people get their protein from seafood," he said.

The report comes in wake of findings issued last week by a team led by the National Center for Ecological Analysis and Synthesis which estimates that over 40 per cent of the world's oceans have been heavily impacted by humans and that only four per cent remain relatively pristine.
It also comes amid concern that sea bird chicks in the North Sea may be being choked after being fed on a diet of snake pipefish-a very bony species. Over the past five years snake pipefish numbers have boomed a meeting of the Zoological Society in London was told last week.
One reason for their sharp increase in numbers might be changes in ocean currents bringing the fish into North Sea waters, the experts suggest.

The new UNEP report has been compiled by researchers including ones at UNEP's GRID Arendal centre; UNEP's World Conservation Monitoring Centre and UNEP's Division of Early Warning and Assessment.
It draws on a wide range of new and emerging science including the latest assessment report of the Intergovernmental Panel on Climate Change-the 2,000 plus panel of scientists established by UNEP and the World Meteorological Organisation.

Other contributions have come from organizations and institutions including the University of Plymouth; the Norwegian Institute for Nature Research; the University of British Columbia; the Institute of Zoology; Princeton University; the University of Barcelona and the Sustainable Europe.

Live Earth Concerts

CONCERT FOR A CLIMATE IN CRISIS

"Live Earth is a 24-hour, 7-continent concert series taking place on 7/7/07 that will bring together more than 100 music artists and 2 billion people to trigger a global movement to solve the climate crisis.
Live Earth will reach this worldwide audience through an unprecedented global media architecture covering all media platforms - TV, radio, Internet and wireless channels.
Live Earth marks the beginning of a multi-year campaign led by the Alliance for Climate Protection, The Climate Group and other international organizations to drive individuals, corporations and governments to take action to solve global warming. Former U.S. Vice President Al Gore is the Chair of the Alliance and Partner of Live Earth.
Live Earth was founded by Kevin Wall, the Worldwide Executive Producer of Live 8, an event that brought together one of the largest audiences in history to combat poverty. Wall formed a partnership with Al Gore and the Alliance for Climate Protection to ensure that Live Earth inspires behavioral changes long after 7/7/07.Live Earth will stage official concerts at Giants Stadium in New York; Wembley Stadium in London; Aussie Stadium in Sydney; Copacabana Beach in Rio de Janeiro; Maropeng at the Cradle of Humankind in Johannesburg; Makuhari Messe in Tokyo; the Steps of the Oriental Pearl Tower in Shanghai; and HSH Nordbank Arena in Hamburg.

Performers at the London concert include Madonna, Beastie Boys, Keane, Red Hot Chili Peppers, Razorlight, Duran Duran, Black Eyed Peas, Genesis, Bloc Party, Corinne Bailey Rae, David Gray, Foo Fighters, James Blunt, John Legend, Paolo Nutini, Pussycat Dolls and Metallica.
Its not everyday that 2 billion people rally around a single cause for the betterment of the whole of mankind.
I, myself will attend Live Earth, in London, not only to see some of the Earth’s best musical talent (as well as some not so talented), but also to view this ‘Unity in the World’s Undertakings,’ first hand.
Having some of biggest names in the music industry , as well as former U.S. Vice President Al Gore, behind an initiative fighting for a noble cause is a great example co-operation and unity of thought in the world undertakings. The question is, how sustainable is this endeavor? What is the real solution behind climate change?

This question was asked at a conference on Climate Change, at Oxford University,England in October 2006.
The event was was organised by the Baha’i Agency for Social and Economic Development (BASED-UK) and the International Environment Forum (IEF), a Baha’i-inspired organization.
One of the conclusions of the conference was that the challenges posed by global warming will require a far higher level of collective action and international cooperation than is currently practiced.

Below is an excerpt from a Baha’i World News Story reporting on the conference:
Climate change is "testing mankind’s ability to deal with a collective challenge," said Halldor Thorgeirsson, deputy executive secretary of the United Nations Framework Convention on Climate Change Secretariat (UNFCCC). "The solution itself will fundamentally change how governments cooperate."
In an address titled "The international community’s response to climate change," Dr. Thorgeirsson said the role of greenhouse gases, such as carbon dioxide, in global warming is now well established scientifically and "sufficiently clear to justify nations taking prompt action."
"When it comes to climate change it will not be solved by any one actor on its own," said Dr. Thorgeirsson.
IEF President Arthur Dahl said the purpose of the conference was "to unify these perspectives, relate them to each other" and to "engage the Baha’i community in the process of applying spiritual principles to the practical problems of the world."
Dr. Dahl, a former deputy assistant executive director of the United Nation Environment Program, delivered the keynote presentation on "scientific and faith perspectives" on climate change, saying that most scientists have now concluded that there will be significant warming in the coming years.
"Climate change is going to force humanity to recognize its oneness," said Dr. Dahl. "Whole ecosystems will shift over long distances, if they can move fast enough."
"We are looking at a scale of change this planet has not seen before," said Dr. Dahl. "Sea level has been going up and the scenarios show the trend to continue. It will bring other impacts: food insecurity, water shortages."
Such changes, said Dr. Dahl, will require more than technical solutions. Rather, he said, they will require the application of ethical and spiritual principles so as to create "new value-based economic models" that seek to create a "dynamic, just and thriving social order."
Religion, said Dr. Dahl, can play a key role in strengthening the ethical framework for action on climate change by educating people "about values and global responsibility," creating "motivation for change," and encouraging the sacrifices that will be needed to create sustainable development.

Global warming benefits

Global Warming Benefits

WARMER WINTERS ARE HEALTHIER:

From a purely evolutionary point of view, warm periods have always benefited plants and animals. The world has thrived during the warming periods between the ice ages. Cold periods have always caused serious survival problems for all organisms including mankind. Scientific studies show that there will be 40,000 fewer deaths each year in the U.S. In Britain alone, scientists estimate that about 30,000 deaths a year are related to cold winter weather. Warmer temperatures in the U.S. will reduce medical costs by about $20 billion every year.

WARMER WEATHER WILL OPEN THE NORTHWEST PASSAGE:

As rising temperatures melt glaciers in the Arctic and particularly in Alaska, a new, faster trade route will soon open up. The Bering Strait, a legendarily difficult passage for ships, could become an oceanic super-highway between the hemispheres as ice sheets disappear. The seldom-used strait is set to become the Panama Canal of the north, cutting down travel time between Europe, America and Asia by as much as one-third. Experts predict the Northwest Passage will be open for year-round travel within a decade. This would be of particular importance for supertankers which are too big to fit through the Panama Canal and currently are forced to go around the tip of South America. This reduction of sea lane ice in the Arctic will be a dramatic boon to the shipping industry carrying cargo between the continents.

WARMER WEATHER MEANS MORE CROPS:

Satellite measurements now show that our planet has become greener than it was prior to the onset of global warming. The rising carbon dioxide concentrations in the atmosphere dramatically increases overall global food production. The presence of carbon dioxide has a fertilizing effect on the growth of plant life. The warmer weather means a longer growing season, and thus greater output. This, combined with fewer frosts and more precipitation, among other factors, will greatly benefit all of the agricultural economic sectors, plus the positive impacts on forestry and recreation. In addition to the dramatic increase of actual land available for cultivation, natural resources would be much easier to extract. The overall economic impact of global warming on the U.S. economy will actually be positive, creating a measurable increase in Gross Domestic Product.

WARMER WEATHER MEANS MORE USABLE LAND:

As the ice retreats to the poles, more arable land will become available for both residential and agricultural purposes. Large land-masses in the northern hemisphere, just south of the Canadian/U.S. border, have some very extreme climates that can be quite inhospitable for human habitation. Most Canadians live in a belt running along its southern border with the United States. But once global warming is factored in, vast northern regions will become arable and comfortably habitable. All of Canada will welcome an agricultural boon field with long growing seasons. Heretofore uninhabitable land will not only become inhabitable, but even temperate.
The process of converting northern US and Canadian forests and grasses to cropland will have a positive cooling effect, because agricultural crops reflect more sunlight and release more moisture into the air. This expanded agriculture will counteract global warming by as much as fifty-percent across parts of North America, Canada, Europe, and Asia. The old boreal forests of both Canada and Russia add to global warming since these pine and waxy leafed trees are darker, thereby absorbing more heat, and, because of their leaf structure, do not evaporate cooling water into the surrounding air. The replacement of boreal forests with more tropical trees will dramatically aid in balancing and diminishing the negative affects of global warming.

WARMER WINTERS ARE SAFER:

With most streets free from ice and snow, driving will be a lot safer; No need to shovel snow reducing the stress induced heart attacks; Heating bills will be drastically lower; No need to waste money on all of that cold weather gear. Rail, road and air transportation would be positively impacted by a general warming since weather-related delays and accidents would be greatly reduced. Department of Energy studies show that consumer energy bills would be reduced by over $12 billion each year.
Global warming will have no real effect, positive or negative, on economic activities such as manufacturing, retailing, wholesaling, banking, education and the majority of other businesses that are unrelated to cold weather. Of course cold weather activities, such as snow-sports, would be negatively affected.

10 Best ways to reduce global warming

Burning fossil fuels such as natural gas, coal, oil and gasoline raises the level of carbon dioxide in the atmosphere, and carbon dioxide is a major contributor to the green house effect and global warming.

You can help to reduce the demand for fossil fuels, which in turn reduces global warming, by using energy more wisely. Here are 10 simple actions you can take to help reduce global warming.

1. Reduce, Reuse, Recycle
Do your part to reduce waste by choosing reusable products instead of disposables. Buying products with minimal packaging (including the economy size when that makes sense for you) will help to reduce waste. And whenever you can, recycle paper,plastic, newspaper, glass and aluminum cans. If there isn't a recycling programme at your workplace, school, or in your community, ask about starting one. By recycling half of your household waste, you can save 2,400 pounds of carbon dioxide annually.

2. Use Less Heat and Air Conditioning
Adding insulation to your walls and attic, and installing weather stripping or caulking around doors and windows can lower your heating costs more than 25 percent, by reducing the amount of energy you need to heat and cool your home.
Turn down the heat while you’re sleeping at night or away during the day, and keep temperatures moderate at all times. Setting your thermostat just 2 degrees lower in winter and higher in summer could save about 2,000 pounds of carbon dioxide each year.

3. change a light bulb
Wherever practical, replace regular light bulbs with compact fluorescent light (CFL) bulbs. Replacing just one 60-watt incandescent light bulb with a CFL will save you $30 over the life of the bulb. CFLs also last 10 times longer than incandescent bulbs, use two-thirds less energy, and give off 70 percent less heat.
If every U.S. family replaced one regular light bulb with a CFL, it would eliminate 90 billion pounds of greenhouse gases, the same as taking 7.5 million cars off the road.

4. Drive less Drive smart
Less driving means fewer emissions. Besides saving gasoline, walking and biking are great forms of exercise. Explore your community’s mass transit system, and check out options for carpooling to work or school.
When you do drive, make sure your car is running efficiently. For example, keeping your tires properly inflated can improve your gas mileage by more than 3 percent. Every gallon of gas you save not only helps your budget, it also keeps 20 pounds of carbon dioxide out of the atmosphere.

5. Buy Energy-Efficient Products
When it's time to buy a new car, choose one that offers good gas mileage. Home appliances now come in a range of energy-efficient models, and compact florescent bulbs are designed to provide more natural-looking light while using far less energy than standard light bulbs.
Avoid products that come with excess packaging, especially molded plastic and other packaging that can't be recycled. If you reduce your household garbage by 10 percent, you can save 1,200 pounds of carbon dioxide annually.

6. Use Less Hot Water
Set your water heater at 120 degrees to save energy, and wrap it in an insulating blanket if it is more than 5 years old. Buy low-flow showerheads to save hot water and about 350 pounds of carbon dioxide yearly. Wash your clothes in warm or cold water to reduce your use of hot water and the energy required to produce it. That change alone can save at least 500 pounds of carbon dioxide annually in most households. Use the energy-saving settings on your diswasher and let the dishes air-dry.

7. Use the "Off" Switch
Save electricity and reduce global warming by turning off lights when you leave a room, and using only as much light as you need. And remember to turn off your television, video player, stereo and computer when you're not using them.
It's also a good idea to turn off the water when you're not using it. While brushing your teeth, shampooing the dog or washing your car, turn off the water until you actually need it for rinsing. You'll reduce your water bill and help to conserve a vital resource.

8. Plant a tree
If you have the means to plant a tree, start digging. During photosynthesis, trees and other plants absorb carbon dioxide and give off oxygen. They are an integral part of the natural atmospheric exchange cycle here on Earth, but there are too few of them to fully counter the increases in carbon dioxide caused by automobile traffic, manufacturing and other human activities. A single tree will absorb approximately one ton of carbon dioxide during its lifetime.

9. Get a report card from your utility companies
Many utility companies provide free home energy audits to help consumers identify areas in their homes that may not be energy efficient. In addition, many utility companies offer rebate programs to help pay for the cost of energy-efficient upgrades.

10. Encourage Others to Conserve
Share information about recycling and energy conservation with your friends, neighbors and co-workers, and take opportunities to encourage public officials to establish programs and policies that are good for the environment.
These 10 steps will take you a long way toward reducing your energy use and your monthly budget. And less energy use means less dependence on the fossil fuels that create greenhouse gases and contribute to global warming.

Global warming may increase kidney stones

U.S. researchers predict global warming may increase kidney stone incidence

Among the many diseases predicted to come with climate change, a team of U.S. researchers say kidney stones may become more common as the temperature rises across North America. Researchers from University of Texas examined how the incidence of kidney stones would change with increasing temperatures and suggest kidney stones may increase across the United States by as much as 30 percent in the most affected areas.

In addition, they calculate the direct and indirect costs of treating approximately 2 million new kidney stone cases annually could increase by 1 billion U.S. dollars by 2050, which is 25 percent more than the current expenditures.Previous research has found the risk of kidney stone formation is increased by low urine volume, which reflects the state of body hydration.

While the response of kidney stone formation to temperature increase is uncertain, the authors note kidney stone incidence is higher in warmer parts of the country, especially the southeast, presumably due to fluid loss in warm climate.
They caution if the risk increases directly with temperature, high-population coastal regions could see the largest increases.

If the risk suddenly climbs steeply at some threshold temperature, a band stretching from Kentucky to northern California would likely see the most new cases.

The higher temperature may be causing some floating icebergs to melt, but this will not make the oceans rise. Icebergs are large floating chunks of ice. In order to float, the iceberg displaces a volume of water that has a weight equal to that of the iceberg. Submarine use this principle to rise and sink in the water by changing their weight.

But the rising temperature and icebergs could play a small role in the rising ocean level. Icebergs are chunks of frozen glaciers that break off from landmasses and fall into the ocean. The rising temperature may be causing more icebergs to form by weakening the glaciers, causing more cracks and making ice more likely to break off. As soon as the ice falls into the ocean, the ocean rises a little.

If the rising temperature affects glaciers and icebergs, could the polar ice caps be in danger of melting and causing the oceans to rise? This could happen, but no one knows when it might happen.

The main ice covered landmass is Antartica at the South Pole, with about 90 percent of the world's ice (and 70 percent of its fresh water). Antarctica is covered with ice an average of 2,133 meters (7,000 feet) thick. If all of the Antarctic ice melted, sea levels around the world would rise about 61 meters (200 feet). But the average temperature in Antarctica is -37°C, so the ice there is in no danger of melting. In fact in most parts of the continent it never gets above freezing.

At the other end of the world, the North Pole, the ice is not nearly as thick as at the South Pole. The ice floats on the Arctic Ocean. If it melted sea levels would not be affected.
There is a significant amount of ice covering Greenland, which would add another 7 meters (20 feet) to the oceans if it melted. Because Greenland is closer to the equator than Antarctica, the temperatures there are higher, so the ice is more likely to melt.

But there might be a less dramatic reason than polar ice melting for the higher ocean level -- the higher temperature of the water. Water is most dense at 4 degrees Celsius. Above and below this temperature, the density of water decreases (the same weight of water occupies a bigger space). So as the overall temperature of the water increases it naturally expands a little bit making the oceans rise.

In 1995 the Intergovernmental Panel on Climate Change issued a report which contained various projections of the sea level change by the year 2100. They estimate that the sea will rise 50 centimeters (20 inches) with the lowest estimates at 15 centimeters (6 inches) and the highest at 95 centimeters (37 inches). The rise will come from thermal expansion of the ocean and from melting glaciers and ice sheets. Twenty inches is no small amount -- it could have a big effect on coastal cities, especially during storms.)

FACTS ON POLAR ICE CAPS

1.Polar ice cap
(Reference:-Wikipedia,the free encyclopedia.)






A polar ice cap is a high-latitude region of a planet or moon that is covered in ice. There are no requirements with respect to size or composition for a body of ice to be termed a polar ice cap, nor any geological requirement for it to be over land; only that it must be a body of solid phase matter in the polar region. This causes the term 'polar ice cap' to be somewhat of a misnomer, as the term ice cap itself is applied with greater scrutiny as such bodies must be found over land, and possess a surface area of less than 50,000 km²: larger bodies are referred to as ice sheets.


The composition of the ice will vary. For example Earth's polar ice caps are mainly water ice, while Mars's polar ice caps are a mixture of solid phase carbon dioxide and water ice.


Polar ice caps form because high-latitude regions receive less energy in the form of solar radiation from the sun than equatorial regions, resulting in lower surface temperatures.

The polar ice caps have changed dramatically over the last 20 years. According to prevalent scientific theory, this change can be attributed to global warming resulting from climate change caused largely by the burning of fossil fuels. Seasonal variations of the ice caps takes place due to varied solar energy absorption as the planet or moon revolves around the sun. Additionally, in geologic time scales, the ice caps may grow or shrink due to climate variation. See ice age, polar climate.


2.Impacts of global warming on polar ice caps
This is a very important statement to think about how Global warming may have significant impacts on our environment over the next century. Many say that it is currently responsible for changes in weather and climate patterns already. The short-term variability of the weather makes it very hard to base decisions on only a few years’ observations, but the long-term trends (measurements over a hundred years) do indicate that we are on a warming trend.




EARTH POLAR ICE CAPS
North pole
Earth's north pole is covered by floating pack ice (sea ice) over the Arctic Ocean, the Arctic ice pack. Portions of the ice that don't melt seasonally can get very thick, up to 3–4 meters thick over large areas, with ridges up to 20 meters thick. One-year ice is usually about a meter thick. The area covered by sea ice ranges between 9 and 12 million km². In addition, the Greenland ice sheet covers about 1.71 million km² and contains about 2.6 million km³ of ice.

While the International Panel on Climate Change 2001 report predicted that the North polar ice cap would last to 2100 in spite of global warming caused by climate change, the dramatic reduction in the size of the ice cap during the northern summer of 2007 has led some scientists to estimate that there will be no ice at the North Pole by 2030 with devastating effects on the environment.

Other scientists such as Wieslaw Maslowski, a professor at the Naval Postgraduate School, estimate that there will be no summer ice by as soon as 2013. He argues that this projection is already too conservative as his dataset did not include the minima of 2005 and 2007.

Due to the Global warming(climate change)northern polar ice cap is being melted far beyond than the south pole.Melting of north polar ice cap is so rapid.



South pole
The land mass of the Earth's south pole, in Antarctica, is covered by the Antarctic ice sheet. It covers an area of almost 14 million km² and contains 25-30 million km³ of ice. Around 70% of the fresh water on the Earth is held in this ice sheet. In addition, the West Antarctic Ice Sheet covers 3.2 million km² and the Ross Ice Shelf covers 0.5 million km². See Climate of Antarctica.


Global warming has increased the volume of summer meltwater on glaciers, which has weakened ice shelves. The dramatic collapses of The Prince Gustav Channel, Larsen Inlet, Larsen A, Wordie, Muller, and the Jones Ice Shelf show the impacts of climate change on the Antarctic ice cap.




EFFECT OF POLAR ICE CAP MELTATION ON RISE OF OCEAN
You may have heard about global warming. It seems that in the last 100 years the earth's temperature has increased about half a degree Celsius. This may not sound like much, but even half a degree can have an effect on our planet. According to the U.S.
Environmental Protection Agency (EPA) the sea level has risen 6 to 8 inches (15 to 20 cm) in the last 100 years.



MARS POLAR ICE CAP

The planet Mars also has polar ice caps, but they consist of frozen
carbon dioxide as well as water. The ice caps change with the Martian seasons-the carbon dioxide ice sublimes in summer, uncovering a surface of layered rocks, and then reforms in winter. These polar ice caps are one of the main reasons that people believe that life exists on Mars.

Global warming on Mars?
In the other study, led by Michael C. Malin, features at the south pole were observed to retreat by up to 10 feet (3 meters) from one Martian year to the next.

The odd shapes -- circular pits, ridges and mounds -- were first photographed in 1999. Since then, the features have eroded away by up to 50 percent.
The pits are growing, the ridges between them shrinking.
Caplinger and Malin caution that a year's worth of data does not reveal when this erosion began or how long it will continue. Yet they speculate that the features could have been created in a Mars' decade and may erode away completely within one to two decades.
"We know that the pits we see at the surface today are not very old, and that they will not last very long," Malin said.

Water or not on mars?

The rate of erosion suggests the features are made of moderately dense but solid carbon dioxide, rather than water ice, the scientists conclude. But that does not preclude the possibility of water ice at the south pole.
"We don't know what's underneath," Caplinger said. "You could certainly have water ice under carbon dioxide."
He said the only way to find out is to go there and drill down.
The newly observed melting, if it is part of a trend, could pump enough carbon dioxide in the atmosphere of Mars to increase its mass by 1 percent per decade, the scientists said. Already, the atmosphere of Mars is roughly 95 percent carbon dioxide.
Caplinger said no one knows for sure what effect the extra carbon dioxide might have on the climate. "Not much," he figures.
But he said many scientists assume that Mars undergoes climate change. Photos of the surface suggest water may once have flowed on Mars, implying that it would have been warmer. And Earth's ice ages offer the lesson that change is inherent in a climate