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Old Saturday, July 15, 2006
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Default Global warming

Global warming will be the greatest environmental challenge in the 21st century."
- Vice President, Albert Gore.
One of the most current and widely discussed factor which could lead to the ultimate end of existence of Earth and man is global warming and its devastating effects. Scientists have asked how fast the Earth is heating up, and how the warming effects on Earth may effect crops and climatic conditions. Several current trends clearly demonstrate that global warming is directly impacting on; rising sea levels, the melting of icecaps, and significant worldwide climatic changes.
is important to understand and discuss the significance of global warming. Global warming is also known as the "Greenhouse effect". The "Greenhouse Earth" is surrounded by a shield of atmospheric gases, rather than a glass or a plastic cover. The air that makes up our atmosphere consists primarily of nitrogen and oxygen molecules (N2 at 78% and O2 at 21%). A large number of "trace gases" make up the remainder of air's composition. Many of these, including carbon dioxide (CO2) and methane (CH4) are the so called "greenhouse" gases
According to scientists, we can with "99% confidence conclude that current temperatures represent a real warming trend rather than a chance fluctuation over the 30-year period." Most scientists agree that the planet's temperature has risen 0.5 degrees Celsius since 1900, and will continue to increase at an increasing rate. The environment is responding to this warming. For instance, a study of mountain plants in the Alps (Europe), shows that some cold-loving plants are starting to move to higher and cooler altitudes. That is a possible response to increasing temperatures.
Global warming has great effect on crops and weather conditions around the world. The northern hemisphere contains more land area than the southern hemisphere, and conversely, a lower percentage of the world's oceans.Global warming has great effect on crops and weather conditions around the world. The northern hemisphere contains more land area than the southern hemisphere, and conversely, a lower percentage of the world's oceans.
Technology is partly responsible for explosive population growth and responsible for the resulting damage to Earth's resources. The industrial revolution caused a rapid increase in the Population growth, as oil and gas fuels were exploited for our use. There is a clear link between the problems of global warming and overpopulation, as increases in CO2 levels follows growth in population.
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Old Sunday, July 16, 2006
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Unfortunatly for Gore, he also said he invented the internet. Should you believe any polititian? i would have my reservations with that.

The fact is that the temperature of earth has constantly been changing. We dont have accurate records from a longer period of time to really compare the data. We all know that the temperature of earth changed on its own. And saying that temperature increased .5 C over last 30 years due to the human activities must not be taken with seriousness.
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Old Monday, July 17, 2006
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Interesting debate !

Well a nominal rise of .5 C maybe dismissed with a shake of head but try ignoring a global rise of 3 DEGREES CENTIGRADE this century.It means frequent floods,skin cancers,standing crop damage and fatal natural calamities.
But look at the brighter side : We get to ride in solar energy cars!!
No one is listening,until you make a mistake !!
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Old Monday, January 15, 2007
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Red face Global Warming

CONSIDER the humble polar bear: Ursus maritimus to the scientists who admire it for its intelligence. Now consider President Bush, who might be classified as Executum obstreperum by the thousands of scientists who say his administration fails to appreciate the gravity of global warming. Is it possible that the polar bear can do what the scientists cannot?
What the polar bear could do, essentially, is force the administration to take steps to curb global warming. With its proposal, announced last week, to list polar bears as a threatened species, the US Fish and Wildlife Service for the first time acknowledged that global warming is the driving force behind an animal’s potential extinction.

If the polar bear is listed as endangered, then the US government would be bound by law to protect it — and protecting it may require regulations to reduce greenhouse gas emissions.

In the polar bear, the administration may have met its match. This isn’t just any animal — it is a creature at once majestic and cuddly, the star attraction at countless zoos and featured in so many TV commercials it practically qualifies for a SAG card.

If that’s not enough, the same type of habitat loss threatening the bears’ survival also endangers the penguin, which had a better year at the box office than all but a few humans.

Less popular is the administration’s stance on global warming. Bush has acknowledged the phenomenon, but he’s reluctant to require industry to cut greenhouse gas emissions. If the polar bear is listed as an endangered species, would the government have to crack down on the carbon emissions that are threatening its existence?

Interior Secretary Dirk Kempthorne passed the buck on that question, saying such regulations fall to other departments. That’s arguable; Fish and Wildlife is the lead agency charged with protecting species from the effects of pollution. If nothing else, a listing for the polar bear would expose Fish and Wildlife to lawsuits from environmentalists similar to the one against the Environmental Protection Agency that is now before the Supreme Court; a dozen states, including California, say the agency is ignoring its duty to protect public health by not regulating greenhouse gases.

—Los Angeles Times

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Old Tuesday, March 20, 2007
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Default environment shows risks

environment shows risks

Global warming is 'very likely' caused by humans and that climate change will continue for centuries even if heat-trapping gases are reduced. Despite the dire outlook, rise in sea level and the most catastrophic storms and droughts can be avoided if prompt action is taken

By 2020, the United States will emit almost one-fifth more gases that lead to global warming than it did in 2000, increasing the risks of drought and scarce water supplies.

The United States already is responsible for one-quarter of the world's carbon dioxide and other 'greenhouse' gases that scientists blame for global warming.

The report, projects that the current administration's climate policy would result in the emission of 9.2 billion tons of greenhouse gases in 2020, a 19 percent increase from 7.7 billion tons in 2000.

According to a UN report, global warming is 'very likely' caused by mankind and that climate change will continue for centuries even if heat-trapping gases are reduced. The report was approved by 113 nations including the United States. Despite the dire outlook, most scientists say, huge sea level rises and the most catastrophic storms and droughts can be avoided if prompt action is taken.

"We're on a path to exceeding levels of global warming that will cause catastrophic consequences, and we really need to be seriously reducing emissions, not just reducing the growth rate as the president is doing," said Michael McCracken, chief scientist at the nonpartisan climate institute in Washington.

Among the consequences of a warming world is 'a distinct reduction in spring snow pack in the northwestern United States,' which supplies much of that regions' water, said Rick Piltz, director of Climate Science Watch, a nonprofit watchdog programme. Final report will evade a full discussion of how global warming might affect the nation.

"I think it is very likely that the main reason the report has been held up for more than a year beyond the deadline is because the administration is reluctant to make an honest statement about likely climate change impacts on this country," said Piltz, a former senior associate with the Federal Climate Change Science Programme.

Shortly after taking office, Bush rejected the 1997 Kyoto Protocol, a UN treaty that was to have required industrial nations to cut global warming gases by 2012 by an average five percent below 1990 levels.

He argued that cutting the US share to below six billion tons a year, as the treaty would have required, would have cost five million US jobs. He objected, too, that such high-polluting developing nations as China and India are not required to reduce emissions.

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Old Tuesday, April 10, 2007
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Default Global warming

Global warming

Global Warming, is increase in the average temperature of the atmosphere, oceans, and landmasses of Earth. The planet has warmed (and cooled) many times during the 4.65 billion years of its history. At present Earth appears to be facing a rapid warming, which most scientists believe results, at least in part, from human activities. The prevailing scientific opinion on climate change is that "most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations," by the burning of fossil fuels, such as coal, oil, and natural gas, which releases into the atmosphere carbon dioxide and other substances known as greenhouse gases , land clearing, and agriculture which leads to warming of the surface and lower atmosphere by increasing the greenhouse effect. Other phenomena such as solar variation and volcanoes have had smaller but non-negligible effects on global mean temperature since 1950. A few scientists disagree about the primary causes of the observed warming. As the atmosphere becomes richer in these gases, it becomes a better insulator, retaining more of the heat provided to the planet by the Sun.

The average surface temperature of Earth is just below 15°C (59°F). Over the last century, this average has risen by about 0.6 Celsius degree (1 Fahrenheit degree). Scientists predict further warming of 1.4 to 5.8 Celsius degrees (2.5 to 10.4 Fahrenheit degrees) by the year 2100. This global temperature rise is expected to melt polar ice caps and glaciers as well as warm the oceans, all of which will expand ocean volume and raise sea level by an estimated 9 to 100 cm (4 to 40 in), flooding some coastal regions and even entire islands. changes in the amount and pattern of precipitation Some regions in warmer climates will receive more rainfall than before, but soils will dry out faster between storms. These changes may increase the frequency and intensity of extreme weather events, such as floods, droughts, heat waves, hurricanes, and tornados. Other consequences include higher or lower agricultural yields, glacier retreat, reduced summer streamflows, species extinctions and increases in the ranges of disease vectors. Warming is expected to affect the number and magnitude of these events; however, it is difficult to connect particular events to global warming. Although most studies focus on the period up to 2100, even if no further greenhouse gases were released after this date warming (and sea level) would be expected to continue to rise for more than a millennium, since carbon dioxide (CO2) has a long average atmospheric lifetime.

This soil desiccation may damage food crops, disrupting food supplies in some parts of the world. Plant and animal species will shift their ranges toward the poles or to higher elevations seeking cooler temperatures, and species that cannot do so may become extinct. The potential consequences of global warming are so great that many of the world's leading scientists have called for international cooperation and immediate action to counteract the problem.
An increase in temperatures can in turn cause other changes, including a rising sea level and. Remaining scientific uncertainties include the exact degree of climate change expected in the future, and especially how changes will vary from region to region across the globe. A hotly contested political and public debate also has yet to be resolved, regarding whether anything should be done, and what could be cost-effectively done to reduce or reverse future warming, or to deal with the expected consequences. Most national governments have signed and ratified the Kyoto Protocol aimed at combating global warming.

History of Global warming

Relative to the period 1860-1900, global temperatures on both land and sea have increased by 0.75 °C (1.4 °F), according to the instrumental temperature record; the urban heat island is not believed to be significant. Since 1979, land temperatures have increased about twice as fast as ocean temperatures (0.25 °C/decade against 0.13 °C/decade). Temperatures in the lower troposphere have increased between 0.12 and 0.22 °C (0.22 and 0.4 °F) per decade since 1979, according to satellite temperature measurements. Over the one or two thousand years before 1850, temperature is believed to have been relatively stable, with possibly regional fluctuations such as the Medieval Warm Period or the Little Ice Age.
Based on estimates by NASA's Goddard Institute for Space Studies, 2005 was the warmest year since reliable, widespread instrumental measurements became available in the late 1800s, exceeding the previous record set in 1998 by a few hundredths of a degree. Estimates prepared by the World Meteorological Organization and the UK Climatic Research Unit concluded that 2005 was the second warmest year, behind 1998.
The attribution of recent climate change is clearest for the most recent period of the last 50 years, for which the most detailed data are available.
The anthropogenic emissions of other pollutants-notably sulphate aerosols-exert a cooling effect; this partially accounts for the plateau/cooling seen in the temperature record in the middle of the twentieth century, though this may also be due to intervening natural cycles
Here are gathered in chronological sequence the most important events in the history of climate change science. The list of milestones includes major influences external to the science itself.


Level of carbon dioxide gas (CO2) in the atmosphere, as later measured in ancient ice, is about 290 ppm (parts per million).

First Industrial Revolution. Coal, railroads, and land clearing speed up greenhouse gas emission, while better agriculture and sanitation speed up population growth.


Joseph Fourier calculates that the Earth would be far colder if it lacked an atmosphere.


Tyndall discovers that some gases block infrared radiation. He suggests that changes in the concentration of the gases could bring climate change.


Arrhenius publishes first calculation of global warming from human emissions of CO2.


Chamberlin produces a model for global carbon exchange including feedbacks.


Second Industrial Revolution. Fertilizers and other chemicals, electricity, and public health further accelerate growth.


World War I. Governments learn to mobilize and control industrial societies.


Opening of Texas and Persian Gulf oil fields inaugurates era of cheap energy.


Global warming trend since late 19th century reported.

Milankovitch proposes orbital changes as the cause of ice ages.


Callendar argues that CO2 greenhouse global warming is underway, reviving interest in the question.


World War II. Grand strategy is largely driven by a struggle to control oil fields.


U.S. Office of Naval Research begins generous funding of many fields of science, some of which happen to be useful for understanding climate change.


Ewing and Donn offer a feedback model for quick ice age onset.

Phillips produces a somewhat realistic computer model of the global atmosphere.

Plass calculates that adding CO2 to the atmosphere will have a significant effect on the radiation balance.


Launch of Soviet Sputnik satellite. Cold War concerns support 1957-58 International Geophysical Year, bringing new funding and coordination to climate studies.

Revelle finds that CO2 produced by humans will not be readily absorbed by the oceans.


Telescope studies show a greenhouse effect raises temperature of the atmosphere of Venus far above the boiling point of water.


Downturn of global temperatures since the early 1940s is reported.

Keeling accurately measures CO2 in the Earth’s atmosphere and detects an annual rise. The level is 315 ppm.


Cuban Missile Crisis, peak of the Cold War.


Calculations suggest that feedback with water vapor could make the climate acutely sensitive to changes in CO2 level.


Boulder meeting on causes of climate change, in which Lorenz and others point out the chaotic nature of the climate system and the possibility of sudden shifts.


Emiliani’s analysis of deep-sea cores shows the timing of ice ages was set by small orbital shifts, suggesting that the climate system is sensitive to small changes.


International Global Atmospheric Research Program established, mainly to gather data for better short-range weather prediction but including climate.

Manabe and Wetherald make a convincing calculation that doubling CO2 would raise world temperatures a couple of degrees.


Studies suggest a possibility of collapse of Antarctic ice sheets, which would sea levels catastrophically.


Astronauts walk on the Moon, and people perceive the Earth as a fragile whole.

Budyko and Sellers present models of catastrophic ice-albedo feedbacks.

Nimbus III satellite begins to provide comprehensive global atmospheric temperature measurements.


First Earth Day. Environmental movement attains strong influence, spreads concern about global degradation.

Creation of U.S. National Oceanic and Atmospheric Administration, the world’s leading funder of climate research.

Aerosols from human activity are shown to be increasing swiftly. Bryson claims they counteract global warming and may bring serious cooling.


SMIC conference of leading scientists reports a danger of rapid and serious global climate change caused by humans, calls for an organized research effort.

Mariner 9 spacecraft finds a great dust storm warming the atmosphere of Mars, plus indications of a radically different climate in the past.


Ice cores and other evidence show big climate shifts in the past between relatively stable modes in the span of a thousand years or so.


Oil embargo and price rise bring first “energy crisis.”


Serious droughts and other unusual weather since 1972 increase scientific and public concern about climate change, with cooling from aerosols suspected to be as likely as warming; journalists talk of ice age.


Concern about environmental effects of airplanes leads to investigations of trace gases in the stratosphere and discovery of danger to ozone layer.

Manabe and collaborators produce complex but plausible computer models which show a temperature rise of several degrees for doubled CO2.


Studies find that CFCs (1975) and also methane and ozone (1976) can make a serious contribution to the greenhouse effect

Deep-sea cores show a dominating influence from 100,000-year Milankovitch orbital changes, emphasizing the role of feedbacks.

Deforestation and other ecosystem changes are recognized as major factors in the future of the climate.

Eddy shows that there were prolonged periods without sunspots in past centuries, corresponding to cold periods.


Scientific opinion tends to converge on global warming as the biggest climate risk in next century.


Attempts to coordinate climate research in U.S. end with an inadequate National Climate Program Act, accompanied by temporary growth in funding.


Second oil “energy crisis.” Strengthened environmental movement encourages renewable energy sources, inhibits nuclear energy growth.

U.S. National Academy of Sciences report finds it highly credible that doubling CO2 will bring 1.5-4.5EC global warming.

World Climate Research Programme launched to coordinate international research.


Election of Reagan brings backlash against environmental movement; political conservatism is linked to skepticism about global warming.

IBM Personal Computer introduced. Advanced economies are increasingly delinked from energy.

Hansen and others show that sulfate aerosols can significantly cool the climate, raising confidence in models showing future greenhouse warming.

Some scientists predict greenhouse warming “signal” should be visible by about the year 2000.


Greenland ice cores reveal drastic temperature oscillations in the span of a century in the distant past.

Strong global warming since mid-1970s is reported, with 1981 the warmest year on record.


Reports from U.S. National Academy of Sciences and Environmental Protection Agency spark conflict, as greenhouse warming becomes prominent in mainstream politics.


Villach conference declares expert consensus that some global warming seems inevitable, calls on governments to consider international agreements to restrict emissions.

Antarctic ice cores show that CO2 and temperature went up and down together through past ice ages, pointing to powerful biological and geochemical feedbacks.

Broecker speculates that a reorganization of North Atlantic Ocean circulation can bring swift and radical climate change.


Montreal Protocol of theVienna Convention imposes international restrictions on emission of ozone-destroying gases.


News media coverage of global warming leaps upward following record heat and droughts plus testimony by Hansen.

Toronto Conference calls for strict, specific limits on greenhouse gas emissions.

Ice-core and biology studies confirm living ecosystems make climate feedback by way of methane, which could accelerate global warming.

Intergovernmental Panel on Climate Change (IPCC) is established.

Level of CO2 in the atmosphere reaches 350 ppm.

After 1988 it is difficult to identify historical milestones. Not only do we lack perspective, but the effort was so large that progress on a given topic, even more than before, came through a variety of results spread over several groups and several years.



Fossil-fuel and other industries form Global Climate Coalition in US to lobby politicians and convince the media and public that climate science is too uncertain to justify action.


First IPCC report says world has been warming and future warming seems likely. Industry lobbyists and some scientists dispute the tentative conclusions.


Mt. Pinatubo explodes; Hansen predicts cooling pattern, verifying (by 1995) computer models of aerosol effects.

Global warming skeptics emphasize studies indicating that a significant part of 20th-century temperature changes were due to solar influences. (The correlation would fail in the following decade.)

Studies from 55 million years ago show possibility of eruption of methane from the seabed with enormous self-sustained warming.


Conference in Rio de Janeiro produces UN Framework Convention on Climate Change, but US blocks calls for serious action.

Study of ancient climates reveals climate sensitivity in same range as predicted independently by computer models.


Greenland ice cores suggest that great climate changes (at least on a regional scale) can occur in the space of a single decade.


Second IPCC report detects "signature" of human-caused greenhouse effect warming, declares that serious warming is likely in the coming century.

Reports of the breaking up of Antarctic ice sheets and other signs of actual current warming in polar regions begin affecting public opinion.


Toyota introduces Prius in Japan, first mass-market electric hybrid car; swift progress in large wind turbines and other energy alternatives.

International conference produces Kyoto Protocol, setting targets to reduce greenhouse gas emissions if enough nations sign onto a treaty.


The warmest year on record, globally averaged (1995, 1997, and 2001-2006 were near the same level). Borehole data confirm extraordinary warming trend.

Qualms about arbitrariness in computer models diminish as teams model ice-age climate and dispense with special adjustments to reproduce current climate.


Criticism that satellite measurements show no warming are dismissed by National Academy Panel.

Ramanathan detects massive "brown cloud" of aerosols from South Asia.


Global Climate Coalition dissolves as many corporations grapple with threat of warming, but oil lobby convinces US administration to deny problem.

Variety of studies emphasize variability and importance of biological feedbacks in carbon cycle, liable to accelerate warming.


Third IPCC report states baldly that global warming, unprecedented since end of last ice age, is "very likely," with possible severe surprises. Effective end of debate among all but a few scientists.

Bonn meeting, with participation of most countries but not US, develops mechanisms for working towards Kyoto targets.

National Academy panel sees a "paradigm shift" in scientific recognition of the risk of abrupt climate change (decade-scale).

Warming observed in ocean basins; match with computer models gives a clear signature of greenhouse effect warming.


Studies find surprisingly strong "global dimming," due to pollution, has retarded arrival of greenhouse warming, but dimming is now decreasing.


Variety of studies increase concern that collapse of ice sheets (West Antarctica, perhaps Greenland) can raise sea levels faster than most had believed.

Deadly summer heat wave in Europe accelerates divergence between European and US public opinion.


In controversy over temperature data covering past millenium, most conclude climate variations were substantial, but not comparable to the post-1980 warming.

First major book, movie and art work featuring global warming appear.


Kyoto treaty goes into effect, signed by major industrial nations except US. Japan, Western Europe, regional US entities accelerate work to retard emissions.
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Old Tuesday, April 10, 2007
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carbondioxide variations

Carbon dioxide during the last 400,000 years and the rapid rise since the Industrial Revolution; changes in the Earth's orbit around the Sun, known as Milankovitch cycles, are believed to be the pacemaker of the 100,000 year ice age cycle.
The climate system varies through natural, internal processes and in response to variations in external "forcing" from both human and natural causes. These forcing factors include solar activity, volcanic emissions, variations in the earth's orbit (orbital forcing) and greenhouse gases. The detailed causes of the recent warming remain an active field of research, but the scientific consensus identifies greenhouse gases as the main influence.
Contrasting with this consensus view, other hypotheses have been proposed to explain all or most of the observed increase in global temperatures, including: the warming is within the range of natural variation; the warming is a consequence of coming out of a prior cool period, namely the Little Ice Age; and the warming is primarily a result of variances in solar radiation.
Adding carbon dioxide (CO2) or methane (CH4) to Earth's atmosphere, with no other changes, will make the planet's surface warmer. Greenhouse gases create a natural greenhouse effect without which temperatures on Earth would be an estimated 30 °C (54 °F) lower, so that Earth would be uninhabitable. It is therefore not correct to say that there is a debate between those who "believe in" and "oppose" the greenhouse effect as such. Rather, the debate concerns the net effect of the addition of greenhouse gases when allowing for compounding or mitigating factors.
One example of an important feedback process is ice-albedo feedback. The increased CO2 in the atmosphere warms the Earth's surface and leads to melting of ice near the poles. As the ice melts, land or open water takes its place. Both land and open water are on average less reflective than ice, and thus absorb more solar radiation. This causes more warming, which in turn causes more melting, and this cycle continues.
Due to the thermal inertia of the Earth's oceans and slow responses of other indirect effects, the Earth's current climate is not in equilibrium with the forcing imposed by increased greenhouse gases. Climate commitment studies indicate that, even if greenhouse gases were stabilized at present day levels, a further warming of about 0.5 °C (0.9 °F) would still occur.

Types of Greenhouse Gases

Recent increases in atmospheric CO2. The monthly CO2 measurements display small seasonal oscillations in an overall yearly uptrend; each year's maximum is reached during the northern hemisphere's late spring, and declines during the northern hemisphere growing season as plants remove some CO2 from the atmosphere.

The greenhouse effect, first discovered by Joseph Fourier in 1824, and first investigated quantitatively by Svante Arrhenius in 1896, is the process in which the emission of infrared radiation by atmospheric gasses warms a planet's surface. On Earth, the major natural greenhouse gases are water vapor, which causes about 36-70% of the greenhouse effect (not including clouds); carbon dioxide, which causes 9-26%; methane, which causes 4-9%, and ozone, which causes 3-7%.

Greenhouse gases occur naturally in the environment and also result from human activities. By far the most abundant greenhouse gas is water vapor, which reaches the atmosphere through evaporation from oceans, lakes, and rivers.
Carbon dioxide is the next most abundant greenhouse gas. It flows into the atmosphere from many natural processes, such as volcanic eruptions; the respiration of animals, which breathe in oxygen and exhale carbon dioxide; and the burning or decay of organic matter, such as plants. Carbon dioxide leaves the atmosphere when it is absorbed into ocean water and through the photosynthesis of plants, especially trees. Photosynthesis breaks up carbon dioxide, releasing oxygen into the atmosphere and incorporating the carbon into new plant tissue.
Humans escalate the amount of carbon dioxide released to the atmosphere when they burn fossil fuels, solid wastes, and wood and wood products to heat buildings, drive vehicles, and generate electricity. At the same time, the number of trees available to absorb carbon dioxide through photosynthesis has been greatly reduced by deforestation, the long-term destruction of forests by indiscriminate cutting of trees for lumber or to clear land for agricultural activities.
Ultimately, the oceans and other natural processes absorb excess carbon dioxide in the atmosphere. However, human activities have caused carbon dioxide to be released to the atmosphere at rates much faster than that at which Earth’s natural processes can cycle this gas. In 1750 there were about 281 molecules of carbon dioxide per million molecules of air (abbreviated as parts per million, or ppm). In 2006 two major scientific organizations-the World Meteorological Organization (WMO) and the United States National Oceanic and Atmospheric Administration (NOAA)-reported that levels of carbon dioxide in the atmosphere had hit a record high. Using different measurement techniques, the WMO said carbon dioxide levels had risen to 377 ppm, an annual increase of 1.8 ppm, and the NOAA reported a figure of 381 ppm for a yearly increase of 2.6 ppm. If current predictions prove accurate, by the year 2100 carbon dioxide will reach concentrations of more than 540 to 970 ppm. At the highest estimation, this concentration would be triple the levels prior to the Industrial Revolution, the widespread replacement of human labor by machines that began in Britain in the mid-18th century and soon spread to other parts of Europe and to the United States. Methane is an even more effective insulator, trapping over 20 times more heat than does the same amount of carbon dioxide. Methane is emitted during the production and transport of coal, natural gas, and oil. Methane also comes from rotting organic waste in landfills, and it is released from certain animals, especially cows, as a byproduct of digestion. Since the beginning of the Industrial Revolution in the mid-1700s, the amount of methane in the atmosphere has more than doubled.
Nitrous oxide is a powerful insulating gas released primarily by burning fossil fuels and by plowing farm soils. Nitrous oxide traps about 300 times more heat than does the same amount of carbon dioxide. The concentration of nitrous oxide in the atmosphere has increased 17 percent over preindustrial levels.

In addition, greenhouse gases are produced in many manufacturing processes. Perfluorinated compounds result from the smelting of aluminum. Hydrofluorocarbons form during the manufacture of many products, including the foams used in insulation, furniture, and car seats. Refrigerators built in some developing nations still use chlorofluorocarbons as coolants. In addition to their ability to retain atmospheric heat, some of these synthetic chemicals also destroy Earth’s high-altitude ozone layer, the protective layer of gases that shields Earth from damaging ultraviolet radiation. For most of the 20th century these chemicals have been accumulating in the atmosphere at unprecedented rates. But since 1995, in response to regulations enforced by the Montréal Protocol on Substances that Deplete the Ozone Layer and its amendments, the atmospheric concentrations of many of these gases are either increasing more slowly or decreasing.
Scientists are growing concerned about other gases produced from manufacturing processes that pose an environmental risk. In 2000 scientists identified a substantial rise in atmospheric concentrations of a newly identified synthetic compound called trifluoromethyl sulfur pentafluoride. Atmospheric concentrations of this gas are rising quickly, and although it still is extremely rare in the atmosphere, scientists are concerned because the gas traps heat more effectively than all other known greenhouse gases. Perhaps more worrisome, scientists have been unable to confirm the industrial source of the gas.
Even a modest rise in sea level will greatly change coastal ecosystems. A 50-cm (20-in) rise will submerge about half of the present coastal wetlands of the United States. New marshes will form in many places, but not where urban areas and developed landscapes block the way. This sea-level rise will cover much of the Florida Everglades.
Scientists use elaborate computer models of temperature, precipitation patterns, and atmosphere circulation to study global warming. Based on these models, scientists have made several predictions about how global warming will affect weather, sea levels, coastlines, agriculture, wildlife, and human health.

Earth's Protection Shield is Being Destroyed -Ozone Depletion and Global Warming

Stratospheric Ozone
The Earth's atmosphere is made up of different layers. The layer closest to the surface is called the troposphere which extends from the Earth's surface up to about 10 kilometers. The ozone layer is located above the troposphere in the stratosphere (10 km to about 50 km high). Stratospheric ozone is Earth's natural protection for all life forms, shielding our planet from harmful ultraviolet-B (UV-B) radiation. UV-B radiation is harmful to humans, animals, and plant life. The ozone layer is being destroyed by certain industrial chemicals including ozone depleting refrigerants, halons, and methyl bromide, a deadly pesticide used on crops.
Ozone depletion damage gets much worse when the stratosphere is very cold. This has been the case the past two years, causing extensive ozone depletion. This past winter, ozone depletion reached the most severe levels ever recorded over the Northern Hemisphere. Western United States ozone levels also continue to drop 3-4 percent per decade. Even if all of our efforts to stop harmful emissions are successful, the ozone layer is not expected to begin recovery until around 2020 at the earliest.

Global Warming Can Increase Ozone Depletion

Scientist's are concerned that continued global warming will accelerate ozone destruction and increase stratospheric ozone depletion. Ozone depletion gets worse when the stratosphere (where the ozone layer is), becomes colder. Because global warming traps heat in the troposphere, less heat reaches the stratosphere which will make it colder. Greenhouse gases act like a blanket for the troposphere and make the stratosphere colder. In other words, global warming can make ozone depletion much worse right when it is supposed to begin its recovery during the next century.

After carbon emissions caused by humans, deforestation is the second principle cause of atmospheric carbn dioxide.Deforestation is responsible for 25% of all carbon emissions entering the atmosphere, by the burning and cutting of about 34 million acres of trees each year. We are losing millions of acres of rainforests each year, the equivalent in area to the size of Italy.The destroying of tropical forests alone is throwing hundreds of millions of tons of carbon dioxide into the atmosphere each year. We are also losing temperate forests. The temperate forests of the world account for an absorption rate of 2 billion tons of carbon annually. In the temperate forests of Siberia alone, the earth is losing 10 million acres per year.
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Effects of global warming

A Weather

Scientists predict that during global warming, the northern regions of the Northern Hemisphere will heat up more than other areas of the planet, northern and mountain glaciers will shrink, and less ice will float on northern oceans. Regions that now experience light winter snows may receive no snow at all. In temperate mountains, snowlines will be higher and snowpacks will melt earlier. Growing seasons will be longer in some areas. Winter and nighttime temperatures will tend to rise more than summer and daytime ones.

The warmed world will be generally more humid as a result of more water evaporating from the oceans. Scientists are not sure whether a more humid atmosphere will encourage or discourage further warming. On the one hand, water vapor is a greenhouse gas, and its increased presence should add to the insulating effect. On the other hand, more vapor in the atmosphere will produce more clouds, which reflect sunlight back into space, which should slow the warming process

Greater humidity will increase rainfall, on average, about 1 percent for each Fahrenheit degree of warming. (Rainfall over the continents has already increased by about 1 percent in the last 100 years.) Storms are expected to be more frequent and more intense. However, water will also evaporate more rapidly from soil, causing it to dry out faster between rains. Some regions might actually become drier than before. Winds will blow harder and perhaps in different patterns. Hurricanes, which gain their force from the evaporation of water, are likely to be more severe. Against the background of warming, some very cold periods will still occur. Weather patterns are expected to be less predictable and more extreme.

B Sea Levels
As the atmosphere warms, the surface layer of the ocean warms as well, expanding in volume and thus raising sea level. Warming will also melt much glacier ice, especially around Greenland, further swelling the sea. Sea levels worldwide rose 10 to 25 cm (4 to 10 in) during the 20th century, and IPCC scientists predict a further rise of 9 to 88 cm (4 to 35 in) in the 21st century.

Sea-level changes will complicate life in many coastal regions. A 100-cm (40-in) rise could submerge 6 percent of The Netherlands, 17.5 percent of Bangladesh, and most or all of many islands. Erosion of cliffs, beaches, and dunes will increase. Storm surges, in which winds locally pile up water and raise the sea, will become more frequent and damaging. As the sea invades the mouths of rivers, flooding from runoff will also increase upstream. Wealthier countries will spend huge amounts of money to protect their shorelines, while poor countries may simply evacuate low-lying coastal regions.

Global warming making hurricanes worse
Global warming doesn't create hurricanes, but it does make them stronger and more dangerous. Because the ocean is getting warmer, tropical storms can pick up more energy and become more powerful. So global warming could turn, say, a category 3 storm into a much more dangerous category 4 storm. In fact, scientists have found that the destructive potential of hurricanes has greatly increased along with ocean temperature over the past 35 years. Hurricane Katrina and other major tropical storms spur debate over impact of global warming on storm intensity.

Effect on glaciers

Global warming has led to negative glacier mass balance, causing glacier retreat around the world. There is a net decline in 142 of the 144 mountain glaciers with records from 1900 to 1980. Since 1980 global glacier retreat has increased significantly. Similarly, Dyurgerov and Meier (2005) averaged glacier data across large-scale regions (e.g. Europe) and found that every region had a net decline from 1960 to 2002, though a few local regions (e.g. Scandinavia) have shown increases. Some glaciers that are in disequilibrium with present climate have already disappeared and increasing temperatures are expected to cause continued retreat in the majority of alpine glaciers around the world. Upwards of 90% of glaciers reported to the World Glacier Monitoring Service have retreated since 1995

Of particular concern is the potential for failure of the Hindu Kush and Himalayan glacial melts. The melt of these glaciers is a large and reliable source of water for China, India, and much of Asia, and these waters form a principal dry-season water source. Increased melting would cause greater flow for several decades, after which "some areas of the most populated region on Earth are likely to 'run out of water'

D Agriculture

A warmed globe will probably produce as much food as before, but not necessarily in the same places. Southern Canada, for example, may benefit from more rainfall and a longer growing season. At the same time, the semiarid tropical farmlands in some parts of Africa may become further impoverished. Desert farm regions that bring in irrigation water from distant mountains may suffer if the winter snowpack, which functions as a natural reservoir, melts before the peak growing months. Crops and woodlands may also be afflicted by more insects and plant diseases.

E. Animals and Plants

Animals and plants will find it difficult to escape from or adjust to the effects of warming because humans occupy so much land. Under global warming, animals will tend to migrate toward the poles and up mountainsides toward higher elevations, and plants will shift their ranges, seeking new areas as old habitats grow too warm. In many places, however, human development will prevent this shift. Species that find cities or farmlands blocking their way north or south may die out. Some types of forests, unable to propagate toward the poles fast enough, may disappear.

Global Warming Could Doom Male Crocodiles
Rising temperatures could force the birth of more female crocodiles and fewer males, an expert said today. The scenario could cause some croc populations to disappear.
Crocodile gender is determined by temperature during incubation. Nest temperatures of 89.6 to 91.4 degrees Fahrenheit (32-33 Celsius) result in males. Anything warmer or cooler produces females. Temperatures typically vary from the top of a nest to the bottom, producing both genders.
A difference of 0.5 - 1º [Celsius] in incubation temperature results in markedly different sex ratios,More female hatchlings due to the cooler or hotter incubation temperatures could lead to eventual extirpation of the species from an area

Global Warming Could Trigger Insect Population Boom

A rise in the Earth’s temperature could lead to an increase in the number of insects worldwide, with potentially dire consequences for humans, a new study suggests.

New research shows that insect species living in warmer areas are more likely to undergo rapid population growth because they have higher metabolic rates and reproduce more frequently. The finding has scientists concerned that global warming could give rise to more fast-growing insect populations and that we could see a spike in the number of six-legged critters.
Insect-borne diseases are also a worry. Malaria, Lyme Disease and a host of others rely on insect vectors to spread among humans, and a swell in their populations could mean more infections.
Already, scientists have observed a widening of malarial zones with new cases appearing in previously unaffected areas. The change is thought to be due to rising temperatures and an expansion of areas habitable for mosquitoes. The new research, detailed in the October issue of The American Naturalist, shows rising temperatures would mean insects would not only spread out, but also multiply more quickly.

Oceans Warming With Coral Bleaching & Disintegration In March, 2006 researchers discovered devastating loss of coral in the Caribbean off Puerto Rico and the Virgin Islands. "It's an unprecedented die-off,"The mortality is of the extremely slow-growing reef-building corals. These are corals that are the foundation of the reef ...
The Caribbean is actually better off than areas of the Indian and Pacific ocean where mortality rates - mostly from warming waters - have been in the 90 percent range in past years.

In October, 2000 at the Ninth International Coral Reef Symposium, held on the island of Bali, researchers warned that more than 25% of the world's coral reefs have been destroyed by pollution and global warming. Scientists emphasized that most of the damage to coral is inflicted by global warming through coral bleaching, the result of higher water temperatures heating the coral. The warming waters stress the coral, which then expels the microscopic plants or algae that give the coral color and nourishes it. Most of the remaining coral could be dead in 20 years, if global warming and pollution continue. Coral reefs around the Maldives and Seychelles islands in the Indian Ocean have taken the brunt of warming seas, as 90% of these corals have been killed over the past two years. Some of the coral reefs, long described as undersea rainforests, home to marine ecosystems that sustain thousands of species of fish and other marine life, have been alive for up to 2.5 million years.

According to Rupert Ormond, a marine biologist from Glasgow University, the world's coral reefs will be dead within 50 years because of global warming, and there is nothing we can do to save

Global Warming Sparks Increased Plant Production in Arctic Lakes
Biological activity in some Arctic lakes has ratcheted up dramatically over the past 150 years as a result of global warming, according to a new study.In six lakes, researchers dug deep into the sediment to measure the amount "chlorophyll-a," the main pigment involved in photosynthesis. When plants convert sunlight to energy, they make chlorophyll-a.The amount of chlorophyll-a is two to five times higher in recent times compared to ancient sediment.The results mean there is more biological activity, more production, in the lakes now compared to the past.

Allergies Getting Worse Due to Global Warming
Sea levels are rising, polar ice caps are melting, hurricanes are getting stronger, and thanks to climate change, people are sneezing more.

The rapid rise in occurrence of allergic symptoms over the past few decades may be due to environmental changes such as mounting carbon dioxide and a warmer atmosphere, a new study finds.

Approximately 40 million Americans suffer from hay fever, while 16 million adults endure asthma. Although genetics play an important role in these conditions, recent research is finding that higher temperatures and more carbon dioxide are making allergy seasons worse, stimulating plants to produce more pollen and increasing fungi growth.
Flowering earlier

Due to global warming and climate change there is the change in plant flowering times and airborne pollen concentrations over the last few decades. The results mean an increase in photosynthesis and more plant growth. Plants are flowering significantly earlier over time and advancing the season by approximately 0.8 days per year

A separate study found plant growth is increasing in Arctic lakes, for example. In addition, total seasonal pollen is increasing for many plants, an example of which is ragweed.

The actual cause of the increase in allergic diseases is due to many factors such as lifestyle changes, obesity, and pollution. This leaves a much larger population sensitive to the increase in aeroallergens, airborne particles that cause allergies. Because of climate change, these aeroallergens are becoming more abundant in the environment and causing all those newly allergic people to potentially have stronger or more frequent symptoms.
More mold

Other studies predict that a warming planet will bring more intense rainstorms. Carbon dioxide levels are expected to elevate further. In response, molds are likely to become common in more homes.

"With an increase in moisture as we might expect as a result of climate change, we can expect more fungal growth on damp interior surfaces, Exposure to fungi is very clearly associated with both allergy and asthma symptoms."

Effect on Infectious Diseases

Most infectious diseases are transmitted by insects and rodents. Transmitters of disease are called vectors. For example, mosquitoes transmit malaria, dengue and viral encephalitis (inflammation of the brain). Like other animals and plants, vectors are accustomed to certain climate conditions. If the climate becomes warmer, the mosquito will try to fly to new places where it can survive and expose more people to the disease. Changes in sea surface temperature and sea level can lead to higher incidence of water-borne infectious and toxin-related illnesses such as malaria (severe chills and fever), cholera (intestinal disease), dengue (characterized by severe pains in the joints and back), and leishmaniasis (skin ulcers).
Human susceptibility to infections can be further compounded by malnutrition. UV-B radiation from ozone depletion damages both plants and animals. UV-B harms amphibian eggs, midge larvae and trout. Crops that are damaged will reduce food availability. UV-B also can damage mammalian immune systems which makes humans and other animals more susceptible to infectious diseases.

Effects on Earth's Food Chain

Ozone depletion and global warming have harmful effects on plants and animals. If allowed to continue, our food chain will be seriously disrupted. For example, phytoplantkton are tiny floating algae in the ocean which are the base of the marine food chain. In Antarctica, there has been upwards of 50 percent ozone depletion. This means that an unusually high amount of UV-B radiation has reached the Earth's surface in the Antarctic region. UV-B harms the productivity of phytoplankton, thereby reducing the available food for animals that feed on phytoplankton. Krill eat phytoplankton and penguins eat krill. From a climate change perspective, phytoplankton normally absorb a lot of carbon from the air. As phytoplankton dies from UV-B radiation, this carbon is no longer absorbed. This means that more carbon will be left in the atmosphere, contributing to more global warming. More global warming can increase ozone depletion, which kills more phytoplankton, and the process repeats itself.
Approximately 92 million people are expected to become refugees from global warming and climate change by 2100, not including any added from population growth.

What country is the largest source of global warming pollution?

The United States. Though Americans make up just 4 percent of the world's population, we produce 25 percent of the carbon dioxide pollution from fossil-fuel burning -- by far the largest share of any country. In fact, the United States emits more carbon dioxide than China, India and Japan, combined. Clearly America ought to take a leadership role in solving the problem. And as the world's top developer of new technologies, we are well positioned to do so -- we already have the know-how.

Mitigation of global warming
The scientific consensus on global warming, together with the precautionary principle and the fear of non-linear climate transition is leading to increasing action to mitigate global warming.
The European Union has set a target of limiting the global temperature rise to 2 °C compared to preindustrial levels, of which 0.8 °C has already taken place and another 0.5 °C is already committed.

The 2 °C rise is typically associated in climate models with a carbon dioxide concentration of 400-500 ppm by volume; the current level as at 2007.Jan is 383 ppm by volume, and rising at 2 ppm annually. Hence, to avoid a very likely breach of the 2 °C target, CO2 levels would have to be stabilised very soon; this is generally regarded as unlikely, based on current programs in place to date.

There are five categories of actions that can be taken to mitigate global warming:

· Reduction of energy use (per person)
· Shifting from carbon-based fossil fuels to alternative energy sources
· Carbon capture and storage
· Geoengineering including carbon sequestration
· Birth control, to lessen demand for resources such as energy and land clearing.
Strategies for mitigation of global warming include development of new technologies; carbon offsets; renewable energy such as biodiesel, solar power, tidal and ocean energy, geothermal power, and wind power; electric or hybrid automobiles; fuel cells; energy conservation; carbon credits; carbon taxes; enhancing natural carbon dioxide sinks; population control; and carbon capture and storage. Many environmental groups encourage individual-lifestyle and political action against global warming, and there has been business action on climate change.

Debates Over Global Warming
Scientists do not all agree about the nature and impact of global warming. A few observers still question whether temperatures have actually been rising at all. Others acknowledge past change but argue that it is much too early to be making predictions for the future. Such critics may also deny that the evidence for the human contribution to warming is conclusive, arguing that a purely natural cycle may be driving temperatures upward. The same dissenters tend to emphasize the fact that continued warming could have benefits in some regions.

Scientists who question the global warming trend point to three puzzling differences between the predictions of the global warming models and the actual behavior of the climate. First, the warming trend stopped for three decades in the middle of the 20th century; there was even some cooling before the climb resumed in the 1970s. Second, the total amount of warming during the 20th century was only about half what computer models predicted. Third, the troposphere, the lower region of the atmosphere, did not warm as fast as the models forecast. However, global warming proponents believe that two of the three discrepancies have now been explained.

The lack of warming at midcentury is now attributed largely to air pollution that spews particulate matter, especially sulfates, into the upper atmosphere. These particulates, also known as aerosols, reflect some incoming sunlight out into space. Continued warming has now overcome this effect, in part because pollution control efforts have made the air cleaner.

The unexpectedly small amount of total warming since 1900 is now attributed to the oceans absorbing vast amounts of the extra heat. Scientists long suspected that this was happening but lacked the data to prove it. In 2000 the U.S. National Oceanic and Atmospheric Administration (NOAA) offered a new analysis of water temperature readings made by observers around the world over 50 years. Records showed a distinct warming trend: World ocean temperatures in 1998 were higher than the 50-year average by 0.2 Celsius degree (0.3 Fahrenheit degree), a small but very significant amount.

The third discrepancy is the most puzzling. Satellites detect less warming in the troposphere than the computer models of global climate predict. According to some critics, the atmospheric readings are right, and the higher temperatures recorded at Earth’s surface are not to be trusted. In January 2000 a panel appointed by the National Academy of Sciences to weigh this argument reaffirmed that surface warming could not be doubted. However, the lower-than-predicted troposphere measurements have not been entirely explained.

National and Local Programs
The developed countries are all working to reduce greenhouse emissions. Several European countries impose heavy taxes on energy usage, designed partly to curb such emissions. Norway taxes industries according to the amount of carbon dioxide they emit. In The Netherlands, government and industry have negotiated agreements aimed at increasing energy efficiency, promoting alternative energy sources, and cutting down greenhouse gas output.

In the United States, the Department of Energy, the Environmental Protection Agency, product manufacturers, local utilities, and retailers have collaborated to implement the Energy Star program. This voluntary program rates appliances for energy use and gives some money back to consumers who buy efficient machines. The Canadian government has established the FleetWise program to cut carbon dioxide emissions from federal vehicles by reducing the number of vehicles it owns and by training drivers to use them more efficiently.

Many local governments are also working against greenhouse emissions by conserving energy in buildings, modernizing their vehicles, and advising the public. Individuals, too, can take steps. The same choices that reduce other kinds of pollution work against global warming. Every time a consumer buys an energy-efficient appliance; adds insulation to a house; recycles paper, metal, and glass; chooses to live near work; or commutes by public transportation, he or she is fighting global warming.

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Post global warming and kyoto protocol

Kyoto protocol
Kyoto Protocol, international treaty adopted in 1997 that sets concrete targets for developed countries to reduce the greenhouse gas emissions that contribute to global warming, also known as climate change. The Kyoto Protocol is a supplementary treaty to the United Nations Framework Convention on Climate Change (UNFCCC) and went into force in February 2005. More than 130 countries are party to it, with this figure set to rise; so far, however, the United States has refused to ratify the treaty.

Under the Kyoto Protocol, developed, or industrialized, countries are subject to legally binding commitments to curb their emissions of the six main greenhouse gases: carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. The targets are based mostly on the emission levels of these pollutants in 1990. In general the treaty calls for industrialized nations to reduce their greenhouse gas emissions by 5 percent below 1990 levels. The target goals must be accomplished by 2012, and commitments to start achieving the targets begin in 2008. Developing countries—that is, most countries in Africa, Asia, and Latin America—are only subject to general commitments.

The Kyoto Protocol is a flexible treaty, allowing individual governments to decide what specific policies and reforms to implement to meet their commitments. It also allows countries to offset some of their emissions by increasing the carbon dioxide absorbed, or sequestered, by trees and other vegetation. However, eligible sequestration activities, and the amount of offsetting allowed, are tightly controlled.

In addition, the Kyoto Protocol established three market-based mechanisms to help bring down the costs of lowering emissions. These mechanisms are known as joint implementation, the clean development mechanism (CDM), and emissions trading. Under joint implementation and the CDM, a country can invest in a project to curb emissions in another country, where it is cheaper to do so, and thereby acquire the resulting credit to offset against its own target. Under emissions trading, a country that exceeds its own target of lowering emissions can transfer the surplus credits to another country that is finding it more difficult to reduce its emissions. Developing countries can participate, but only through the CDM. Safeguards are in place to ensure that emission credits are genuine.

Developed countries are subject to stringent reporting requirements, and a compliance committee considers any suspected noncompliance. Countries commit to achieve a certain level of their target goal beginning in 2008. Any country that fails to meet its emissions target may be penalized by having to meet a proportionally higher target for the following commitment period and by having to prepare an action plan to show how emissions will be reined in.

The entry into force of the Kyoto Protocol was delayed for several years while countries finalized its details. A package of decisions, known as the Marrakech Accords, was finally agreed in 2001, setting out in detail how the protocol’s rules and mechanisms will work. Implementation is now underway, with the CDM already operational. Many businesses are especially keen to participate in the market mechanisms, and the European Union (EU) launched a regional emissions trading system in January 2005. Meeting the protocol’s targets, however, will be a challenge for many countries.

Talks are due to start soon on next steps in the international effort to control climate change. Key controversial issues will include when and how to negotiate stronger commitments for developing countries, and how to secure the participation of the United States. Under the administration of Democratic president Bill Clinton, the United States supported the protocol but never submitted it to Congress for ratification because of opposition from the Republican Party. When Republican George W. Bush became president in 2001, the U.S. withdrew its support for the protocol. Bush claimed that the treaty would harm the U.S. economy and was unfair to industrialized nations because developing countries were not required to control their emissions.
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Arrow In Arctic Ice, Lessons on Effects of Warming

Researchers Drill, Map, Blast In Greenland in Hunt for Clues

If Manhattan floods, it may start here, on an ice field that stretches in frozen silence to every horizon.
Global warming is working away at the Greenland ice cap. The frozen interior of the Arctic island is shedding ice much faster than simple melting should explain. And George Tsoflias wants to know why.
A sharp wind knifes at the hands of the scientist as he struggles -- gloves off in the bitter cold -- to make adjustments to his radar. His instrument is strapped to an unwieldy wooden sled adorned with batteries and cables and two sets of flat antennas that extend like flapping wings over the snow. He hopes it will peer through the ice to the ground two miles below.
Dozens of scientific teams are scattered over the frigid Greenland snowscape, sent by the National Science Foundation, NASA and universities around the world. They are drilling the ice to collect samples, flying over it with radar and lasers, listening to its creaks and groans with seismometers, fitting it with GPS receivers to measure its pace, and photographing it as it slides to the sea and breaks into icebergs.
Their quest is crucial: If all the ice on Greenland were to melt, the seas around the world would rise by 23 feet, submerging countless coastal cities. A modest three-foot rise would endanger 70 million people. "Greenland has the potential to put a lot of water, a lot of ice, into the sea," said Tsoflias, a researcher from the University of Kansas.
Greenland's ice cap contains 800 trillion gallons of water and several outlet glaciers, huge rivers of ice that act as faucets from the ice cap. Those faucets are running faster. The Jakobshavn Glacier where Tsoflias works has doubled its speed in five years and every day dumps enough ice into the sea to supply 20 to 30 New York Cities with water.
From the air, the Jakobshavn looks like a still-life portrait of a river in white, rippled with frozen waves, sinuous as it moves toward the ocean at a rate of 135 feet per day.
"It's the fastest-flowing glacier in the world," said Don Voigt, huddled in a tent a few yards from Tsoflias' people, on a 3-degree day, trying to warm up with hot chocolate and the tiny blue flame of a camp stove. "The question is, why is it flowing so fast?"
Voigt, 53, a white-bearded veteran of 14 field seasons in Greenland and Antarctica, leads a team from Pennsylvania State University mapping the bottom of the ice by setting off explosives and recording the seismic reverberations.
They will live out here for a month, sleeping in tents in the brutal weather, preparing explosive charges with cold-numbed hands, wiping snow off their instruments. They give nicknames to their jobs: "shooter," "recorder" and "potato planter" -- the one who shoves the small charges into the snow.
Scientists have a working theory for the glacier's speed. The Jakobshavn is churning toward the sea over land that forms a trough deeper than the Grand Canyon. As higher temperatures melt ice and snow on the surface, the water is pouring down through crevasses to the rock. There, it is acting as a lubricant, lifting and carrying the glacier faster toward the sea.
"It's like a slick griddle," Paul Winberry, 28, a geophysics doctoral student, said as he tested a steam drill to plant explosives. The ice cap stretches to the horizon in all directions, a perfectly scribed white line against the blue sky. "As soon as that water hits the bottom of the ice sheet, the ice sheet hits the gas and starts to accelerate."
As ice on glaciers moves over rock, it snags and lurches. That creates "icequakes" measurable in the same way as earthquakes. In 1993, there were seven such quakes in Greenland. In 2005, as the ice accelerated, there were 32.
"For a long time it was thought that a change of climate could affect the ice sheets very slowly," said Meredith Nettles, a scientist from Lamont-Doherty Earth Observatory at Columbia University, who monitors a large glacier in eastern Greenland. "Now we believe the Greenland ice can respond to changes in climate much more quickly than anyone thought."
In geologic terms, "quickly" still means decades or centuries. But some scientists say the Earth is approaching a point when the process cannot be stopped. Only in recent years did scientists conclude that sea levels are rising twice as fast as they had estimated, said H. Jay Zwally, a senior research scientist from NASA's Goddard Space Flight Center in Greenbelt, Md.
"We are seeing things taking place in the ice now that weren't expected, that five years ago we didn't even know about," said Zwally, who will spend his 14th summer on the Greenland ice cap this year. "I think eventually Greenland will reach a point that the change is irreversible in the current climate."
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