Saturday, August 21, 2010

Discover the scientific facts on global warming

Many observations indicate that global warming has taken place during the 20th century. Global warming has resulted in a increase of the average surface temperature, a decrease in snow cover and ice extent and a rise of the sea level. Moreover, global warming affects precipitation, cloud cover and extreme temperatures.More...

Natural reasons will always affect global warming. However, human activities are increasing significantly the concentrations of greenhouse gases, mainly CO2) in the atmosphere, resulting in global warming. Although more research is needed, understanding of global warming processes and computer models have improved. global warming models conclude that most of the warming over the last 50 years is likely to have been due to man-made activities. Scenarios are developed to predict what global warming are expected for the future and what the likely consequences will be. More...

Read the GreenFacts Digest on the global warming

What causes this global warming?

global warming has and will always vary for natural reasons. However, human activities are increasing significantly the concentrations of some gases in the atmosphere, such as greenhouse gases (mainly CO2), which tend to warm the earth surface, and anthropogenic aerosols, which mostly tend to cool it.

Although more research is needed, understanding of global warming processes and computer models have improved, leading the IPCC to draw the following conclusion:

Most of the global warming over the last 50 years is likely to have been due to man-made activities. More...

Read the GreenFacts Digest on the global warming effects

What global warmings are expected for the future?

To predict the future global warming, several greenhouse gas emission scenarios were developed and fed into computer models.

They project for the next century that, without specific policy changes:

  • global mean temperature should increase by between 1.4 and 5.8°C (2.5 to 10°F).
  • the Northern Hemisphere cover should decrease further, but the Antarctic ice sheet should increase.
  • the sea level should rise by between 9 and 88 cm (3.5" to 35").
  • other changes should occur, including an increase in some extreme weather events.

After 2100, human induced global warming effects is projected to persist for many centuries. The sea level should continue rising for thousands of years after the climate has been stabilized..

The 10 Scary Facts about Global Warming

Global warming is no joke. Here are 10 facts that will make you think twice before dismissing global warming as somebody else's problem. Find out what you can do to slow down or reverse the trend.
8 Warmest Years On
Record All Since 1998

The warmest year on record was 2005. [1] If things keep going like this, your children and grandchildren will inherit a world with a far less hospitable climate.
Scientists Predict 6-Foot
Rise In Global Sea Level

In the past 100 years, sea level has already risen between 5 and 9 inches and it is still going up. You may think that's not a lot, but it is. Even a few feet of rise would put many US coastal cities and a large portion of Florida underwater. [6]
More Hurricanes In 2005
Than In Any Other Year

There were 27 named storms in 2005, a higher number of severe storms and hurricanes than ever before in a single year. The high storm volume may be connected to warmer temperatures in the Atlantic. [1]
Deadly Infectious Diseases
Spread Beyond The Tropics

Within the last decade, there were outbreaks of both malaria and dengue fever in the US. [2] Other tropical diseases will undoubtedly spread north as the temperature rises.

If we don't do something to stop global warming in the coming years, you and your family may be at risk for diseases that used to be confined to the tropics.
Warming To Cause More
Heat Wave-Related Deaths

Heat waves are gaining in intensity and frequency. Europe's 2003 heat wave caused an estimated 35,000 deaths. [7] If you have older relatives, especially if they live alone, increases in heat waves could pose a deadly risk.
Crop Failures Produce
Global Famine

Global warming causes crop failures, especially in the tropics, where temperatures are already on the edge of what is tolerable for many food crops. These failures could lead to famines if warming continues. [3]
Climate Changing Faster Than
Any Time In Past 10,000 Years
What's scary about this statistic is that rapid change will have unpredictable effects. With this kind of instability, no one knows what our climate will be like in 25, 50, or 100 years. You could be standing in a future desert or a future ocean. One thing is certain, though, our planet as a whole will be a lot better off if we can stabilize global carbon output. [9]
Sixteen Million New Cars
On The Road Every Year

That's really scary when you consider that automobiles are one of the major sources of global carbon emissions. [4]
Global Fossil Fuel
Use Still Increasing
More people than ever are aware that fossil fuel consumption is one of the biggest drivers of global warming. And yet, global fossil fuel use is still going up every single year. Yikes! [9]

Here are a few things you can do to bring down your contribution.
This Whole Mess Is Our Fault

There is a broad scientific consensus that humans are causing global warming by burning fossil fuels when we drive, fly, and use electricity.

Your use of fossil fuels is actually changing the composition of the atmosphere. The US and China are the two biggest emitters of carbon dioxide worldwide.[5]

If we don't make some changes soon, the prognosis is pretty grim. It is up to you to take action. Don't miss your chance.

Top 50 Things To Do To Stop Global Warming

Global Warming is a dramatically urgent and serious problem. We don't need to wait for governments to find a solution for this problem: each individual can bring an important help adopting a more responsible lifestyle: starting from little, everyday things. It's the only reasonable way to save our planet, before it is too late.

Here is a list of 50 simple things that everyone can do in order to fight against and reduce the Global Warming phenomenon: some of these ideas are at no cost, some other require a little effort or investment but can help you save a lot of money, in the middle-long term! - Note: you can read this list in italian too: fermare il riscaldamento globale.

  1. Replace a regular incandescent light bulb with a compact fluorescent light bulb (cfl)
    CFLs use 60% less energy than a regular bulb. This simple switch will save about 300 pounds of carbon dioxide a year.
    We recommend you purchase your CFL bulbs at, they have great deals on both screw-in and plug-in light bulbs.

  2. Install a programmable thermostat
    Programmable thermostats will automatically lower the heat or air conditioning at night and raise them again in the morning. They can save you $100 a year on your energy bill.

  3. Move your thermostat down 2° in winter and up 2° in summer
    Almost half of the energy we use in our homes goes to heating and cooling. You could save about 2,000 pounds of carbon dioxide a year with this simple adjustment.

  4. Clean or replace filters on your furnace and air conditioner
    Cleaning a dirty air filter can save 350 pounds of carbon dioxide a year.

  5. Choose energy efficient appliances when making new purchases
    Look for the Energy Star label on new appliances to choose the most energy efficient products available.

  6. Do not leave appliances on standby
    Use the "on/off" function on the machine itself. A TV set that's switched on for 3 hours a day (the average time Europeans spend watching TV) and in standby mode during the remaining 21 hours uses about 40% of its energy in standby mode.

  7. Wrap your water heater in an insulation blanket
    You’ll save 1,000 pounds of carbon dioxide a year with this simple action. You can save another 550 pounds per year by setting the thermostat no higher than 50°C.

  8. Move your fridge and freezer
    Placing them next to the cooker or boiler consumes much more energy than if they were standing on their own. For example, if you put them in a hot cellar room where the room temperature is 30-35ºC, energy use is almost double and causes an extra 160kg of CO2 emissions for fridges per year and 320kg for freezers.

  9. Defrost old fridges and freezers regularly
    Even better is to replace them with newer models, which all have automatic defrost cycles and are generally up to two times more energy-efficient than their predecessors.

  10. Don't let heat escape from your house over a long period
    When airing your house, open the windows for only a few minutes. If you leave a small opening all day long, the energy needed to keep it warm inside during six cold months (10ºC or less outside temperature) would result in almost 1 ton of CO2 emissions.

  11. Replace your old single-glazed windows with double-glazing
    This requires a bit of upfront investment, but will halve the energy lost through windows and pay off in the long term. If you go for the best the market has to offer (wooden-framed double-glazed units with low-emission glass and filled with argon gas), you can even save more than 70% of the energy lost.

  12. Get a home energy audit
    Many utilities offer free home energy audits to find where your home is poorly insulated or energy inefficient. You can save up to 30% off your energy bill and 1,000 pounds of carbon dioxide a year. Energy Star can help you find an energy specialist.

  13. Cover your pots while cooking
    Doing so can save a lot of the energy needed for preparing the dish. Even better are pressure cookers and steamers: they can save around 70%!

  14. Use the washing machine or dishwasher only when they are full
    If you need to use it when it is half full, then use the half-load or economy setting. There is also no need to set the temperatures high. Nowadays detergents are so efficient that they get your clothes and dishes clean at low temperatures.

  15. Take a shower instead of a bath
    A shower takes up to four times less energy than a bath. To maximize the energy saving, avoid power showers and use low-flow showerheads, which are cheap and provide the same comfort.

  16. Use less hot water
    It takes a lot of energy to heat water. You can use less hot water by installing a low flow showerhead (350 pounds of carbon dioxide saved per year) and washing your clothes in cold or warm water (500 pounds saved per year) instead of hot.

  17. Use a clothesline instead of a dryer whenever possible
    You can save 700 pounds of carbon dioxide when you air dry your clothes for 6 months out of the year.

  18. Insulate and weatherize your home
    Properly insulating your walls and ceilings can save 25% of your home heating bill and 2,000 pounds of carbon dioxide a year. Caulking and weather-stripping can save another 1,700 pounds per year. Energy Efficient has more information on how to better insulate your home.

  19. Be sure you’re recycling at home
    You can save 2,400 pounds of carbon dioxide a year by recycling half of the waste your household generates.

  20. Recycle your organic waste
    Around 3% of the greenhouse gas emissions through the methane is released by decomposing bio-degradable waste. By recycling organic waste or composting it if you have a garden, you can help eliminate this problem! Just make sure that you compost it properly, so it decomposes with sufficient oxygen, otherwise your compost will cause methane emissions and smell foul.

  21. Buy intelligently
    One bottle of 1.5l requires less energy and produces less waste than three bottles of 0.5l. As well, buy recycled paper products: it takes less 70 to 90% less energy to make recycled paper and it prevents the loss of forests worldwide.

  22. Choose products that come with little packaging and buy refills when you can
    You will also cut down on waste production and energy use... another help against global warming.

  23. Reuse your shopping bag
    When shopping, it saves energy and waste to use a reusable bag instead of accepting a disposable one in each shop. Waste not only discharges CO2 and methane into the atmosphere, it can also pollute the air, groundwater and soil.

  24. Reduce waste
    Most products we buy cause greenhouse gas emissions in one or another way, e.g. during production and distribution. By taking your lunch in a reusable lunch box instead of a disposable one, you save the energy needed to produce new lunch boxes.

  25. Plant a tree
    A single tree will absorb one ton of carbon dioxide over its lifetime. Shade provided by trees can also reduce your air conditioning bill by 10 to 15%. The Arbor Day Foundation has information on planting and provides trees you can plant with membership.

  26. Switch to green power
    In many areas, you can switch to energy generated by clean, renewable sources such as wind and solar. In some of these, you can even get refunds by government if you choose to switch to a clean energy producer, and you can also earn money by selling the energy you produce and don't use for yourself.

  27. Buy locally grown and produced foods
    The average meal in the United States travels 1,200 miles from the farm to your plate. Buying locally will save fuel and keep money in your community.

  28. Buy fresh foods instead of frozen
    Frozen food uses 10 times more energy to produce.

  29. Seek out and support local farmers markets
    They reduce the amount of energy required to grow and transport the food to you by one fifth. Seek farmer’s markets in your area, and go for them.

  30. Buy organic foods as much as possible
    Organic soils capture and store carbon dioxide at much higher levels than soils from conventional farms. If we grew all of our corn and soybeans organically, we’d remove 580 billion pounds of carbon dioxide from the atmosphere!

  31. Eat less meat
    Methane is the second most significant greenhouse gas and cows are one of the greatest methane emitters. Their grassy diet and multiple stomachs cause them to produce methane, which they exhale with every breath.

  32. Reduce the number of miles you drive by walking, biking, carpooling or taking mass transit wherever possible
    Avoiding just 10 miles of driving every week would eliminate about 500 pounds of carbon dioxide emissions a year! Look for transit options in your area.

  33. Start a carpool with your coworkers or classmates
    Sharing a ride with someone just 2 days a week will reduce your carbon dioxide emissions by 1,590 pounds a year. runs a free service connecting north american commuters and travelers.

  34. Don't leave an empty roof rack on your car
    This can increase fuel consumption and CO2 emissions by up to 10% due to wind resistance and the extra weight - removing it is a better idea.

  35. Keep your car tuned up
    Regular maintenance helps improve fuel efficiency and reduces emissions. When just 1% of car owners properly maintain their cars, nearly a billion pounds of carbon dioxide are kept out of the atmosphere.

  36. Drive carefully and do not waste fuel
    You can reduce CO2 emissions by readjusting your driving style. Choose proper gears, do not abuse the gas pedal, use the engine brake instead of the pedal brake when possible and turn off your engine when your vehicle is motionless for more than one minute. By readjusting your driving style you can save money on both fuel and car mantainance.

  37. Check your tires weekly to make sure they’re properly inflated
    Proper tire inflation can improve gas mileage by more than 3%. Since every gallon of gasoline saved keeps 20 pounds of carbon dioxide out of the atmosphere, every increase in fuel efficiency makes a difference!

  38. When it is time for a new car, choose a more fuel efficient vehicle
    You can save 3,000 pounds of carbon dioxide every year if your new car gets only 3 miles per gallon more than your current one. You can get up to 60 miles per gallon with a hybrid! You can find information on fuel efficiency on FuelEconomy and on GreenCars websites.

  39. Try car sharing
    Need a car but don’t want to buy one? Community car sharing organizations provide access to a car and your membership fee covers gas, maintenance and insurance. Many companies – such as Flexcar - offer low emission or hybrid cars too! Also, see ZipCar.

  40. Try telecommuting from home
    Telecommuting can help you drastically reduce the number of miles you drive every week. For more information, check out the Telework Coalition.

  41. Fly less
    Air travel produces large amounts of emissions so reducing how much you fly by even one or two trips a year can reduce your emissions significantly. You can also offset your air travel carbon emissions by investingin renewable energy projects.

  42. Encourage your school or business to reduce emissions
    You can extend your positive influence on global warming well beyond your home by actively encouraging other to take action.

  43. Join the virtual march
    The Stop Global Warming Virtual March is a non-political effort to bring people concerned about global warming together in one place. Add your voice to the hundreds of thousands of other people urging action on this issue.

  44. Encourage the switch to renewable energy
    Successfully combating global warming requires a national transition to renewable energy sources such as solar, wind and biomass. These technologies are ready to be deployed more widely but there are regulatory barriers impeding them. U.S. citizens, take action to break down those barriers with Vote Solar.

  45. Protect and conserve forest worldwide
    Forests play a critical role in global warming: they store carbon. When forests are burned or cut down, their stored carbon is release into the atmosphere - deforestation now accounts for about 20% of carbon dioxide emissions each year. Conservation International has more information on saving forests from global warming.

  46. Consider the impact of your investments
    If you invest your money, you should consider the impact that your investments and savings will have on global warming. Check out SocialInvest and Ceres to can learn more about how to ensure your money is being invested in companies, products and projects that address issues related to climate change.

  47. Make your city cool
    Cities and states around the country have taken action to stop global warming by passing innovative transportation and energy saving legislation. If you're in the U.S., join the cool cities list.

  48. Tell Congress to act
    The McCain Lieberman Climate Stewardship and Innovation Act would set a firm limit on carbon dioxide emissions and then use free market incentives to lower costs, promote efficiency and spur innovation. Tell your representative to support it.

  49. Make sure your voice is heard!
    Americans must have a stronger commitment from their government in order to stop global warming and implement solutions and such a commitment won’t come without a dramatic increase in citizen lobbying for new laws with teeth. Get the facts about U.S. politicians and candidates at Project Vote Smart and The League of Conservation Voters. Make sure your voice is heard by voting!

  50. Share this list!
    Send this page via e-mail to your friends! Spread this list worldwide and help people doing their part: the more people you will manage to enlighten, the greater YOUR help to save the planet will be (but please take action on first person too)!

global warming

I'm referring to news articles rather than scientific articles, and avoiding technical discussions in order to keep this article readable to everybody.)

If I told you that the Ganges and the Brahmaputra will both dry up by the year 2035, how hard would you laugh at me? Now, what if it was the world's leading scientific authority on climate change that told you?

I'm sure every one of us knows at least a little bit about global warming: that it is primarily caused by the greenhouse effect, and that greenhouse gas levels in the atmosphere have been rising because of industrialization and deforestation, that rising global temperatures will melt polar ice caps thus causing sea levels to rise, and so on. However, until recently, we've all been led to believe that we have a century or two to cut greenhouse emissions and quell the problem. The key phrase there is "until recently", because climate science has now progressed enough to tell us how bad the situation really is.

How bad will India be hit?
The first sentence of this article must have sent alarm bells ringing in your head. But a little thought will tell you why the Ganges will dry up, if not when: the Ganges, and indeed all perennial rivers in North India, are fed by glaciers in the Himalayas. As global temperatures rise, the glaciers receive snow later and start melting earlier, causing them to gradually fall back to the colder regions. This news article [1] in the Hindu has a detailed discussion about the effect of global warming on glaciers. The world's leading authority on climate change, the Intergovernmental Panel on Climate Change (IPCC), believes that all North Indian rivers will turn seasonal, and ultimately dry up by the year 2035 itself if global warming remains unchecked.

But there's more. Another news article [2] confirms our worst fears: inundation of low-lying areas along the coastline owing to rising sea levels; drastic increase in heat-related deaths; dropping water tables; decreased crop productivity are some of the horrors outlined for us. Falling crop productivity due to the change in the length of the seasons is of particular concern, because there is an acute shortage of arable land in our country. With the population still growing rapidly, and crop productivity dropping, combined with the fact that we are already facing a grain shortage this year and have been forced to procure from abroad, the situation appears dire.

Is it fair? The major contributors to the greenhouse effect thus far are the developed nations, and even on an absolute basis (let us not even go into a per-capita basis), India's contribution to global warming is very little. And yet, we will be among the first to suffer its effects, as the change in climate will decrease crop productivity near the equator but actually increase it in the temperate regions. Effectively, the third world has been offered a very raw deal: suffer for something you didn't do, and still bear the yoke of cutting emissions because, frankly, at this point our planet needs all the help it can get.

How high is safe?
Let us leave India's concerns aside for now, take a step back and look at the global picture. Global temperatures have risen about 0.6 C on an average in the past century. There is a worldwide consensus among scientific circles that the adverse effects of global warming will probably be manageable for a rise in temperature upto 2 C, but beyond that, melting ice caps, unbalanced ecosystems, drastically reduced crop yields, etc. will cause worldwide disaster of monstrous proportions. If I haven't painted the picture clearly enough for you, read this article [3] and this article [4] detailing exactly what countries like Canada and Australia can expect in terms of "disaster".

But, is this where you heave a sigh and think, if it takes a century for the temperature to rise 0.6 C, then we have plenty of time to remedy the situation before the rise reaches 2 C? Wrong. You see, there is a lag between the rise in greenhouse gases and the rise in global temperatures. Scientists give the analogy of heating a metal plate directly, and then indirectly, by placing a metal block between the plate and the heat source: when you place the block, it takes some time before an increase in temperature at the heat source affects the plate; at the same time, if the heat source stabilizes or drops in temperature, the plate will continue to increase in temperature for a while before stabilizing or dropping. Thus, the increase in temperature now is a direct effect of rising greenhouse gas levels sometime in the 20th century. We are yet to reap the effect of the carbon dioxide we are currently dumping into the atmosphere! And the fact is, the amount of greenhouse gases that have been going into the atmosphere has been steadily accelerating over the past century.

So, where should we hold greenhouse gas levels in order to hold the global temperature rise to 2 C? The answer cannot be explained in one sentence, because there is some statistics involved. We cannot accurately predict the temperature rise from carbon dioxide levels yet; we have to talk in terms of probabilities. A recent study by Meinshausen et al. [5] gives some startling numbers. This is actually explained in much simpler terms in this press article [6]. The gist of it is that, we are already past the safe limit! You see, the current level of greenhouse gases in the atmosphere stands at 459 ppm of carbon dioxide equivalent (the actual concentration of CO2, corrected to include the effect of other greenhouse gases). According to the Meinshausen study, if atmospheric greenhouse concentrations are maintained at 450 ppm, the probability of global temperature rise crossing 2 C reaches unacceptable levels (> 50%). The current EU target is 550 ppm - at that level, we will be looking at a rise of around 3 C! In other words, emissions across the world should already be decreasing, not increasing at an accelerating pace. Countries around the world should be spending a significant percentage of their GDPs to save the planet, but everyone seems reluctant to move.

Panels and Reports
I had mentioned the IPCC earlier. The IPCC was formed by the UN and has actually been around since 1988. Over the years, it has established itself as the world's leading authority on climate change. It publishes its findings periodically, the assessment reports published this year being the fourth set, and the most controversial one because it reads more like a disaster movie script than a scientific report. Actually, there had been protests over the previous report that the IPCC is being alarmist, and the UK government ordered an independent study be made (a committee was appointed, led by Nicholas Stern), and its findings were released at the end of October 2006. The Stern Review actually reported that the IPCC had understated the situation in the third assessment report. You see, climate science is far from exact, and the IPCC tends to err on the conservative side. There are already publications that say that the IPCC has been conservative even in the fourth report - read this news article [7].

Perhaps the most important thing that the fourth assessment report has accomplished is that it has finally laid to rest claims that global warming is a myth. Yes, until a few years ago, there wasn't even a global consensus on whether global warming is the fault of man, because the waters got muddied by studies that showed that greenhouse gases, while absorbing heat radiated by the earth, happened to reflect sunlight coming in, thus reducing temperatures. Further, it is believed that geologically, the world is headed towards an ice age. Increasing global temperatures were attributed to periodic properties of the Sun! Now, at last, all these speculations have been laid to rest, and IPCC has stated that there is a 90% probability that the phenomenon of increasing global temperatures is anthropogenic (caused by man), and primarily because of greenhouse gases - what we've suspected all along. India, too, has finally woken up to the threat, and has set up a panel [Citation needed] to investigate the specific effects of global warming on India over the next few decades, and what remedial measures are feasible. The panel is to be headed by Mr. Pachauri himself, the current head of the IPCC.

Global Warming Fast Facts

Global warming, or climate change, is a subject that shows no sign of cooling down.

Here's the lowdown on why it's happening, what's causing it, and how it might change the planet.

Is It Happening?

Yes. Earth is already showing many signs of worldwide climate change.

• Average temperatures have climbed 1.4 degrees Fahrenheit (0.8 degree Celsius) around the world since 1880, much of this in recent decades, according to NASA's Goddard Institute for Space Studies.

• The rate of warming is increasing. The 20th century's last two decades were the hottest in 400 years and possibly the warmest for several millennia, according to a number of climate studies. And the United Nations' Intergovernmental Panel on Climate Change (IPCC) reports that 11 of the past 12 years are among the dozen warmest since 1850.

• The Arctic is feeling the effects the most. Average temperatures in Alaska, western Canada, and eastern Russia have risen at twice the global average, according to the multinational Arctic Climate Impact Assessment report compiled between 2000 and 2004.

• Arctic ice is rapidly disappearing, and the region may have its first completely ice-free summer by 2040 or earlier. Polar bears and indigenous cultures are already suffering from the sea-ice loss.

• Glaciers and mountain snows are rapidly melting—for example, Montana's Glacier National Park now has only 27 glaciers, versus 150 in 1910. In the Northern Hemisphere, thaws also come a week earlier in spring and freezes begin a week later.

• Coral reefs, which are highly sensitive to small changes in water temperature, suffered the worst bleaching—or die-off in response to stress—ever recorded in 1998, with some areas seeing bleach rates of 70 percent. Experts expect these sorts of events to increase in frequency and intensity in the next 50 years as sea temperatures rise.

• An upsurge in the amount of extreme weather events, such as wildfires, heat waves, and strong tropical storms, is also attributed in part to climate change by some experts.

Are Humans Causing It?

The report, based on the work of some 2,500 scientists in more than 130 countries, concluded that humans have caused all or most of the current planetary warming. Human-caused global warming is often called anthropogenic climate change.

• Industrialization, deforestation, and pollution have greatly increased atmospheric concentrations of water vapor, carbon dioxide, methane, and nitrous oxide, all greenhouse gases that help trap heat near Earth's surface. (See an interactive feature on how global warming works.)

• Humans are pouring carbon dioxide into the atmosphere much faster than plants and oceans can absorb it.

• These gases persist in the atmosphere for years, meaning that even if such emissions were eliminated today, it would not immediately stop global warming.

• Some experts point out that natural cycles in Earth's orbit can alter the planet's exposure to sunlight, which may explain the current trend. Earth has indeed experienced warming and cooling cycles roughly every hundred thousand years due to these orbital shifts, but such changes have occurred over the span of several centuries. Today's changes have taken place over the past hundred years or less.

• Other recent research has suggested that the effects of variations in the sun's output are "negligible" as a factor in warming, but other, more complicated solar mechanisms could possibly play a role.

What's Going to Happen?

A follow-up report by the IPCC released in April 2007 warned that global warming could lead to large-scale food and water shortages and have catastrophic effects on wildlife.

• Sea level could rise between 7 and 23 inches (18 to 59 centimeters) by century's end, the IPCC's February 2007 report projects. Rises of just 4 inches (10 centimeters) could flood many South Seas islands and swamp large parts of Southeast Asia.

• Some hundred million people live within 3 feet (1 meter) of mean sea level, and much of the world's population is concentrated in vulnerable coastal cities. In the U.S., Louisiana and Florida are especially at risk.

• Glaciers around the world could melt, causing sea levels to rise while creating water shortages in regions dependent on runoff for fresh water.

• Strong hurricanes, droughts, heat waves, wildfires, and other natural disasters may become commonplace in many parts of the world. The growth of deserts may also cause food shortages in many places.

More than a million species face extinction from disappearing habitat, changing ecosystems, and acidifying oceans.

• The ocean's circulation system, known as the ocean conveyor belt, could be permanently altered, causing a mini-ice age in Western Europe and other rapid changes.

• At some point in the future, warming could become uncontrollable by creating a so-called positive feedback effect. Rising temperatures could release additional greenhouse gases by unlocking methane in permafrost and undersea deposits, freeing carbon trapped in sea ice, and causing increased evaporation of water.

What is Climategate?

In late November 2009, hackers unearthed hundreds of emails at the U.K.'s University of East Anglia that exposed private conversations among top-level British and U.S. climate scientists discussing whether certain data should be released to the public. [Do we know who the hackers were? Were they skeptics? Might be worth noting]

The email exchanges also refer to statistical tricks used to illustrate climate change? trends, and call climate skeptics idiots, according to the New York Times.

One such trick was used to create the well-known hockey-stick graph, which shows a sharp uptick in temperature increases during the 20th century. Former U.S vice president Al Gore relied heavily on the graph as evidence of human-caused climate change in the documentary An Inconvenient Truth.

The data used for this graph come from two sources: thermostat readings and tree-ring samples.

While thermostat readings have consistently shown a temperature rise over the past hundred years, tree-ring samples show temperature increases stalling around 1960.

On the hockey-stick graph, thermostat-only data is grafted onto data that incorporates both thermostat and tree-ring readings, essentially presenting a seamless picture of two different data sets, the hacked emails revealed.

But scientists argue that dropping the tree-ring data was no secret and has been written about in the scientific literature for years.

Climate change skeptics have heralded the emails as an attempt to fool the public, according to the Times.

Yet climate scientists maintain that these controversial points are small blips that are inevitable in scientific research, and that the evidence for human-induced climate change is much broader and still widely accepted............