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.
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.
18 Kasım 2011 Cuma
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.
Global Warming: How Hot? How Soon?
Global Warming Can Be Stopped, World Climate Experts Say
Global Warming Interactive: Learn About Its Causes and Effects
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.
Here's the lowdown on why it's happening, what's causing it, and how it might change the planet.
Global Warming: How Hot? How Soon?
Global Warming Can Be Stopped, World Climate Experts Say
Global Warming Interactive: Learn About Its Causes and Effects
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.
4 Kasım 2011 Cuma
Stopping global warming is risk management
Stopping global warming is risk management
The issue with stopping or reducing global warming is about risk and managing risk: Science still does not know the exact mechanism by which smoking and its associated chemicals causes cancer. What we do know is that smoking is the biggest risk factor in developing lung cancer. The more you smoke, the more your risk of getting lung cancer. Not everyone who smokes gets lung cancer, and not everyone who gets lung cancer has smoked.
Similarly with Climate Change (global warming), we are seeing that temperatures are rising at the same time that atmospheric greenhouse gas levels have gone off the charts over the last 650,000 years.
If the IPCC is right, and we don't do anything, we risk massive temperature increases that will lead to the loss of the great ice sheets of Greenland and Antarctica, resulting in a 20 foot increase in sea levels.That would take about 100 years if we do nothing. Almost all of the major population centers located on coasts (check out the % of Asia, Europe, and North American cities which would be affected.) Global warming causes huge costs if that is right.
If the IPCC is wrong, and we do everything we can to reduce new emissions of greenhouse gases, we would reduce the annual increase of global GDP by 0.12%. Since global GDP is growing around 3%, that is not a big cost.
This is exactly why people buy insurance. Most Americans will never have a fire. Only about 1% will ever have a house fire. However, most Americans buy fire insurance. Why? Managing risks. Science has told us the facts about global waming. It's up to us to manage the risks involved with global warming.
The issue with stopping or reducing global warming is about risk and managing risk: Science still does not know the exact mechanism by which smoking and its associated chemicals causes cancer. What we do know is that smoking is the biggest risk factor in developing lung cancer. The more you smoke, the more your risk of getting lung cancer. Not everyone who smokes gets lung cancer, and not everyone who gets lung cancer has smoked.
Similarly with Climate Change (global warming), we are seeing that temperatures are rising at the same time that atmospheric greenhouse gas levels have gone off the charts over the last 650,000 years.
If the IPCC is right, and we don't do anything, we risk massive temperature increases that will lead to the loss of the great ice sheets of Greenland and Antarctica, resulting in a 20 foot increase in sea levels.That would take about 100 years if we do nothing. Almost all of the major population centers located on coasts (check out the % of Asia, Europe, and North American cities which would be affected.) Global warming causes huge costs if that is right.
If the IPCC is wrong, and we do everything we can to reduce new emissions of greenhouse gases, we would reduce the annual increase of global GDP by 0.12%. Since global GDP is growing around 3%, that is not a big cost.
This is exactly why people buy insurance. Most Americans will never have a fire. Only about 1% will ever have a house fire. However, most Americans buy fire insurance. Why? Managing risks. Science has told us the facts about global waming. It's up to us to manage the risks involved with global warming.
Cause and effect for global warming
Cause of global warming
Almost 100% of the observed temperature increase over the last 50 years has been due to the increase in the atmosphere of greenhouse gas concentrations like water vapour, carbon dioxide (CO2), methane and ozone. Greenhouse gases are those gases that contribute to the greenhouse effect (see below). The largest contributing source of greenhouse gas is the burning of fossil fuels leading to the emission of carbon dioxide.
The greenhouse effect
When sunlight reaches Earth's surface some is absorbed and warms the earth and most of the rest is radiated back to the atmosphere at a longer wavelength than the sun light. Some of these longer wavelengths are absorbed by greenhouse gases in the atmosphere before they are lost to space. The absorption of this longwave radiant energy warms the atmosphere. These greenhouse gases act like a mirror and reflect back to the Earth some of the heat energy which would otherwise be lost to space. The reflecting back of heat energy by the atmosphere is called the "greenhouse effect".
The major natural greenhouse gases are water vapor, which causes about 36-70% of the greenhouse effect on Earth (not including clouds); carbon dioxide CO2, which causes 9-26%; methane, which causes 4-9%, and ozone, which causes 3-7%. It is not possible to state that a certain gas causes a certain percentage of the greenhouse effect, because the influences of the various gases are not additive. Other greenhouse gases include, but are not limited to, nitrous oxide, sulfur hexafluoride, hydrofluorocarbons, perfluorocarbons and chlorofluorocarbons.
Global warming causes by greenhouse effect
Greenhouse gases in the atmosphere (see above) act like a mirror and reflect back to the Earth a part of the heat radiation, which would otherwise be lost to space. The higher the concentration of green house gases like carbon dioxide in the atmosphere, the more heat energy is being reflected back to the Earth. The emission of carbon dioxide into the environment mainly from burning of fossil fuels (oil, gas, petrol, kerosene, etc.) has been increased dramatically over the past 50 years, see graph below.
Almost 100% of the observed temperature increase over the last 50 years has been due to the increase in the atmosphere of greenhouse gas concentrations like water vapour, carbon dioxide (CO2), methane and ozone. Greenhouse gases are those gases that contribute to the greenhouse effect (see below). The largest contributing source of greenhouse gas is the burning of fossil fuels leading to the emission of carbon dioxide.
The greenhouse effect
When sunlight reaches Earth's surface some is absorbed and warms the earth and most of the rest is radiated back to the atmosphere at a longer wavelength than the sun light. Some of these longer wavelengths are absorbed by greenhouse gases in the atmosphere before they are lost to space. The absorption of this longwave radiant energy warms the atmosphere. These greenhouse gases act like a mirror and reflect back to the Earth some of the heat energy which would otherwise be lost to space. The reflecting back of heat energy by the atmosphere is called the "greenhouse effect".
The major natural greenhouse gases are water vapor, which causes about 36-70% of the greenhouse effect on Earth (not including clouds); carbon dioxide CO2, which causes 9-26%; methane, which causes 4-9%, and ozone, which causes 3-7%. It is not possible to state that a certain gas causes a certain percentage of the greenhouse effect, because the influences of the various gases are not additive. Other greenhouse gases include, but are not limited to, nitrous oxide, sulfur hexafluoride, hydrofluorocarbons, perfluorocarbons and chlorofluorocarbons.
Global warming causes by greenhouse effect
Greenhouse gases in the atmosphere (see above) act like a mirror and reflect back to the Earth a part of the heat radiation, which would otherwise be lost to space. The higher the concentration of green house gases like carbon dioxide in the atmosphere, the more heat energy is being reflected back to the Earth. The emission of carbon dioxide into the environment mainly from burning of fossil fuels (oil, gas, petrol, kerosene, etc.) has been increased dramatically over the past 50 years, see graph below.
Global Warming is caused
Global Warming is caused by many things. The causes are split up into two groups, man-made or anthropogenic causes, and natural causes.
Natural Causes
Natural causes are causes created by nature. One natural cause is a release of methane gas from arctic tundra and wetlands. Methane is a greenhouse gas. A greenhouse gas is a gas that traps heat in the earth's atmosphere. Another natural cause is that the earth goes through a cycle of climate change. This climate change usually lasts about 40,000 years.
Man-made Causes
Man-made causes probably do the most damage. There are many man-made causes. Pollution is one of the biggest man-made problems. Pollution comes in many shapes and sizes. Burning fossil fuels is one thing that causes pollution. Fossil fuels are fuels made of organic matter such as coal, or oil. When fossil fuels are burned they give off a green house gas called CO2. Also mining coal and oil allows methane to escape. How does it escape? Methane is naturally in the ground. When coal or oil is mined you have to dig up the earth a little. When you dig up the fossil fuels you dig up the methane as well.
Another major man-made cause of Global Warming is population. More people means more food, and more methods of transportation, right? That means more methane because there will be more burning of fossil fuels, and more agriculture. Now your probably thinking, "Wait a minute, you said agriculture is going to be damaged by Global Warming, but now you're saying agriculture is going to help cause Global Warming?" Well, have you ever been in a barn filled with animals and you smell something terrible? You're smelling methane. Another source of methane is manure. Because more food is needed we have to raise food. Animals like cows are a source of food which means more manure and methane. Another problem with the increasing population is transportation. More people means more cars, and more cars means more pollution. Also, many people have more than one car.
OverpopulationSince CO2 contributes to global warming, the increase in population makes the problem worse because we breathe out CO2. Also, the trees that convert our CO2 to oxygen are being demolished because we're using the land that we cut the trees down from as property for our homes and buildings. We are not replacing the trees (an important part of our eco system), so we are constantly taking advantage of our natural resources and giving nothing back in return.
Natural Causes
Natural causes are causes created by nature. One natural cause is a release of methane gas from arctic tundra and wetlands. Methane is a greenhouse gas. A greenhouse gas is a gas that traps heat in the earth's atmosphere. Another natural cause is that the earth goes through a cycle of climate change. This climate change usually lasts about 40,000 years.
Man-made Causes
Man-made causes probably do the most damage. There are many man-made causes. Pollution is one of the biggest man-made problems. Pollution comes in many shapes and sizes. Burning fossil fuels is one thing that causes pollution. Fossil fuels are fuels made of organic matter such as coal, or oil. When fossil fuels are burned they give off a green house gas called CO2. Also mining coal and oil allows methane to escape. How does it escape? Methane is naturally in the ground. When coal or oil is mined you have to dig up the earth a little. When you dig up the fossil fuels you dig up the methane as well.
Another major man-made cause of Global Warming is population. More people means more food, and more methods of transportation, right? That means more methane because there will be more burning of fossil fuels, and more agriculture. Now your probably thinking, "Wait a minute, you said agriculture is going to be damaged by Global Warming, but now you're saying agriculture is going to help cause Global Warming?" Well, have you ever been in a barn filled with animals and you smell something terrible? You're smelling methane. Another source of methane is manure. Because more food is needed we have to raise food. Animals like cows are a source of food which means more manure and methane. Another problem with the increasing population is transportation. More people means more cars, and more cars means more pollution. Also, many people have more than one car.
OverpopulationSince CO2 contributes to global warming, the increase in population makes the problem worse because we breathe out CO2. Also, the trees that convert our CO2 to oxygen are being demolished because we're using the land that we cut the trees down from as property for our homes and buildings. We are not replacing the trees (an important part of our eco system), so we are constantly taking advantage of our natural resources and giving nothing back in return.
Kaydol:
Kayıtlar (Atom)