Climatologists (scientists who study climate) have analyzed the global warming that has occurred since the late 1800's. A majority of climatologists have concluded that human activities are responsible for most of the warming. Human activities contribute to global warming by enhancing Earth's natural greenhouse effect. The greenhouse effect warms Earth's surface through a complex process involving sunlight, gases, and particles in the atmosphere.
The main human activities that contribute to global warming are the burning of fossil fuels (coal, oil, and natural gas) and the clearing of land. Most of the burning occurs in automobiles, in factories, and in electric power plants that provide energy for houses and office buildings. The burning of fossil fuels creates carbon dioxide, whose chemical formula is CO2. CO2 is a greenhouse gas that slows the escape of heat into space.
http://www.nasa.gov/worldbook/global_warming_worldbook.html
Devastating heat waves sweeping across continents. Poisonous plants producing more potent toxins. Air quality plummeting on summer days. Disease-carrying insects swarming mountain villages.These scenarios aren't the recipe for a summer disaster movie. They're some of the widespread health consequences caused by global warming. And they're happening right now, all over the world.
http://www.nrdc.org/health/effects/globalwarming-map/default.asp
How do we know that human activities—namely the emissions from our tailpipes and smokestacks—are responsible for warming the planet? To Benjamin Santer, a climate scientist at the Lawrence Livermore National Laboratory in California, the answer lies clearly within the data. It turns out that, just as perpetrators leave hard evidence like fingerprints and DNA samples at the scene of a crime, the various causes of climate change leave distinct signatures or patterns that climate scientists can identify if they look carefully enough.
http://www.ucsusa.org/global_warmin...cience/climate-scientist-benjamin-santer.html
Scientists' measurements show that sea levels around the globe have risen by about 1.3 inches per decade since 1990. Precise measurements from satellites as well as tide gauges indicate that this rise has accelerated over the past 20 years, up from the previous rate of 0.7 inch per decade in the last half of the twentieth century. New research suggests that if we continue pumping carbon dioxide into our atmosphere at a high rate globally, the water level along the coasts could rise another 2.6 to 5.3 feet in the next 100 years.
http://www.ucsusa.org/global_warming/science_and_impacts/impacts/preparing-for-sea-level-rise.html
The current emissions trajectory—if allowed to continue (and if Earth's response is at the higher end of values of expected sensitivity to heat-trapping-gas forcing)—indicates that in the next couple of centuries some parts of the world are likely to be too hot for humans. "In our study, we just asked the basic questions. If we burn a lot of carbon and the climate system is sensitive to greenhouse-gas emissions, how bad could it get for humans?" Huber said. "We were disturbed to find that it gets really bad."
http://www.ucsusa.org/global_warming/science_and_impacts/impacts/health-effects-of-heat-waves.html
The planet is warming, from North Pole to South Pole, and everywhere in between. Globally, the mercury is already up more than 1 degree Fahrenheit (0.8 degree Celsius), and even more in sensitive polar regions. And the effects of rising temperatures aren’t waiting for some far-flung future. They’re happening right now. Signs are appearing all over, and some of them are surprising. The heat is not only melting glaciers and sea ice, it’s also shifting precipitation patterns and setting animals on the move.
http://environment.nationalgeographic.com/environment/global-warming/gw-effects/
Glaciers are melting, sea levels are rising, cloud forests are drying, and wildlife is scrambling to keep pace. It's becoming clear that humans have caused most of the past century's warming by releasing heat-trapping gases as we power our modern lives. Called greenhouse gases, their levels are higher now than in the last 650,000 years.
http://environment.nationalgeographic.com/environment/global-warming/gw-overview/
Even if we stopped emitting greenhouse gases (GHGs) today, the Earth would still warm by another degree Fahrenheit or so. But what we do from today forward makes a big difference. Depending on our choices, scientists predict that the Earth could eventually warm by as little as 2.5 degrees or as much as 10 degrees Fahrenheit.
http://environment.nationalgeographic.com/environment/global-warming/gw-solutions/
Each year from 1998 through 2007 ranks among the top 25 warmest years on record for the United States, according to the National Oceanic and Atmospheric Administration. Scientists say that the earth could warm by an additional 7.2 degrees Fahrenheit during the 21st century if we fail to reduce emissions from burning fossil fuels, such as coal and oil. This rise in average temperature will have far-reaching effects on the earth's climate patterns and on all living things. Many of these changes have already begun.
http://www.nrdc.org/globalWarming/fcons.asp
The reduction of the permanent Arctic sea ice by 14 percent since the 1970s is causing not only feeding and breeding difficulties, but also drownings and apparent cannibalism among bears. Government scientists have predicted rapid declines of bears in all but the most northern of the range..
http://www.worldviewofglobalwarming.org/pages/alaska.html
Climate-related changes are already observed in the United States and its coastal waters. These include increases in heavy downpours, rising temperature and sea level, rapidly retreating glaciers, thawing permafrost, lengthening growing seasons, lengthening ice-free seasons in the ocean and on lakes and rivers, earlier snowmelt, and alterations in river flows. These changes are projected to grow.
http://www.worldviewofglobalwarming.org/pages/temperate-zone.html
If global warming emissions continue to rise unabated, we will see growing costs related to climate change. This fact sheet reports some of the projected damages—to our coasts, our health, our energy and water resources, our agriculture, our transportation infrastructure, and our recreational resources—that will occur in states and regions throughout the United States. Making the choice to dramatically lower our emissions at least 80 percent from 2005 levels by 2050 will help avoid some of the worst consequences of climate change.
http://www.ucsusa.org/global_warming/science_and_impacts/impacts/climate-costs-of-inaction.html
Melting glaciers, early snowmelt and severe droughts will cause more dramatic water shortages in the American West.
Rising sea levels will lead to coastal flooding on the Eastern seaboard, in Florida, and in other areas, such as the Gulf of Mexico.
Warmer sea surface temperatures will fuel more intense hurricanes in the southeastern Atlantic and Gulf coasts.
Forests, farms and cities will face troublesome new pests and more mosquito-borne diseases.
Disruption of habitats such as coral reefs and alpine meadows could drive many plant and animal species to extinction.
http://www.nrdc.org/globalWarming/f101.asp?gclid=CLmbpI_Fr6MCFdj75woduHsF6A
Scientists are no longer debating the basic facts of climate change. In February 2007, the thousands of scientific experts collectively known as the Intergovernmental Panel on Climate Change (IPCC) concluded that there is greater than 90 percent likelihood that people are causing global warming. (IPCC, 2007)
These latest findings amplify what other highly respected science organizations say:
In a joint statement with 10 other National Academies of Science, the U.S. National Academy of Sciences said:
"The scientific understanding of climate change is now sufficiently clear to justify nations taking prompt action. It is vital that all nations identify cost-effective steps that they can take now, to contribute to substantial and long-term reduction in net global greenhouse gas emissions."—Joint Statement of Science Academies: Global Response to Climate Change, 2005
The American Geophysical Union, a respected organization comprising over 41,000 Earth and space scientists, wrote in its position on climate change that "natural influences cannot explain the rapid increase in global near-surface temperatures observed during the second half of the 20th century."
http://www.edf.org/page.cfm?tagID=35215&source=ggadgw35215&gclid=CLfrmMLVr6MCFRD75wod6FCM4Q
Levels of carbon dioxide in the atmosphere are higher today than at any time in measurable history.
A study published in the journal Science reports that the current level of carbon dioxide (CO2) in the atmosphere — about 390 parts per million — is higher today than at any time in measurable history — at least the last 2.1 million years. Previous peaks of CO2 were never more than 300 ppm over the past 800,000 years, and the concentration is rising by around 2 ppm each year.
http://www.edf.org/article.cfm?contentID=10717
The main human activities that contribute to global warming are the burning of fossil fuels (coal, oil, and natural gas) and the clearing of land. Most of the burning occurs in automobiles, in factories, and in electric power plants that provide energy for houses and office buildings. The burning of fossil fuels creates carbon dioxide, whose chemical formula is CO2. CO2 is a greenhouse gas that slows the escape of heat into space.
http://www.nasa.gov/worldbook/global_warming_worldbook.html
Devastating heat waves sweeping across continents. Poisonous plants producing more potent toxins. Air quality plummeting on summer days. Disease-carrying insects swarming mountain villages.These scenarios aren't the recipe for a summer disaster movie. They're some of the widespread health consequences caused by global warming. And they're happening right now, all over the world.
http://www.nrdc.org/health/effects/globalwarming-map/default.asp
How do we know that human activities—namely the emissions from our tailpipes and smokestacks—are responsible for warming the planet? To Benjamin Santer, a climate scientist at the Lawrence Livermore National Laboratory in California, the answer lies clearly within the data. It turns out that, just as perpetrators leave hard evidence like fingerprints and DNA samples at the scene of a crime, the various causes of climate change leave distinct signatures or patterns that climate scientists can identify if they look carefully enough.
http://www.ucsusa.org/global_warmin...cience/climate-scientist-benjamin-santer.html
Scientists' measurements show that sea levels around the globe have risen by about 1.3 inches per decade since 1990. Precise measurements from satellites as well as tide gauges indicate that this rise has accelerated over the past 20 years, up from the previous rate of 0.7 inch per decade in the last half of the twentieth century. New research suggests that if we continue pumping carbon dioxide into our atmosphere at a high rate globally, the water level along the coasts could rise another 2.6 to 5.3 feet in the next 100 years.
http://www.ucsusa.org/global_warming/science_and_impacts/impacts/preparing-for-sea-level-rise.html
The current emissions trajectory—if allowed to continue (and if Earth's response is at the higher end of values of expected sensitivity to heat-trapping-gas forcing)—indicates that in the next couple of centuries some parts of the world are likely to be too hot for humans. "In our study, we just asked the basic questions. If we burn a lot of carbon and the climate system is sensitive to greenhouse-gas emissions, how bad could it get for humans?" Huber said. "We were disturbed to find that it gets really bad."
http://www.ucsusa.org/global_warming/science_and_impacts/impacts/health-effects-of-heat-waves.html
The planet is warming, from North Pole to South Pole, and everywhere in between. Globally, the mercury is already up more than 1 degree Fahrenheit (0.8 degree Celsius), and even more in sensitive polar regions. And the effects of rising temperatures aren’t waiting for some far-flung future. They’re happening right now. Signs are appearing all over, and some of them are surprising. The heat is not only melting glaciers and sea ice, it’s also shifting precipitation patterns and setting animals on the move.
http://environment.nationalgeographic.com/environment/global-warming/gw-effects/
Glaciers are melting, sea levels are rising, cloud forests are drying, and wildlife is scrambling to keep pace. It's becoming clear that humans have caused most of the past century's warming by releasing heat-trapping gases as we power our modern lives. Called greenhouse gases, their levels are higher now than in the last 650,000 years.
http://environment.nationalgeographic.com/environment/global-warming/gw-overview/
Even if we stopped emitting greenhouse gases (GHGs) today, the Earth would still warm by another degree Fahrenheit or so. But what we do from today forward makes a big difference. Depending on our choices, scientists predict that the Earth could eventually warm by as little as 2.5 degrees or as much as 10 degrees Fahrenheit.
http://environment.nationalgeographic.com/environment/global-warming/gw-solutions/
Each year from 1998 through 2007 ranks among the top 25 warmest years on record for the United States, according to the National Oceanic and Atmospheric Administration. Scientists say that the earth could warm by an additional 7.2 degrees Fahrenheit during the 21st century if we fail to reduce emissions from burning fossil fuels, such as coal and oil. This rise in average temperature will have far-reaching effects on the earth's climate patterns and on all living things. Many of these changes have already begun.
http://www.nrdc.org/globalWarming/fcons.asp
The reduction of the permanent Arctic sea ice by 14 percent since the 1970s is causing not only feeding and breeding difficulties, but also drownings and apparent cannibalism among bears. Government scientists have predicted rapid declines of bears in all but the most northern of the range..
http://www.worldviewofglobalwarming.org/pages/alaska.html
Climate-related changes are already observed in the United States and its coastal waters. These include increases in heavy downpours, rising temperature and sea level, rapidly retreating glaciers, thawing permafrost, lengthening growing seasons, lengthening ice-free seasons in the ocean and on lakes and rivers, earlier snowmelt, and alterations in river flows. These changes are projected to grow.
http://www.worldviewofglobalwarming.org/pages/temperate-zone.html
If global warming emissions continue to rise unabated, we will see growing costs related to climate change. This fact sheet reports some of the projected damages—to our coasts, our health, our energy and water resources, our agriculture, our transportation infrastructure, and our recreational resources—that will occur in states and regions throughout the United States. Making the choice to dramatically lower our emissions at least 80 percent from 2005 levels by 2050 will help avoid some of the worst consequences of climate change.
http://www.ucsusa.org/global_warming/science_and_impacts/impacts/climate-costs-of-inaction.html
Melting glaciers, early snowmelt and severe droughts will cause more dramatic water shortages in the American West.
Rising sea levels will lead to coastal flooding on the Eastern seaboard, in Florida, and in other areas, such as the Gulf of Mexico.
Warmer sea surface temperatures will fuel more intense hurricanes in the southeastern Atlantic and Gulf coasts.
Forests, farms and cities will face troublesome new pests and more mosquito-borne diseases.
Disruption of habitats such as coral reefs and alpine meadows could drive many plant and animal species to extinction.
http://www.nrdc.org/globalWarming/f101.asp?gclid=CLmbpI_Fr6MCFdj75woduHsF6A
Scientists are no longer debating the basic facts of climate change. In February 2007, the thousands of scientific experts collectively known as the Intergovernmental Panel on Climate Change (IPCC) concluded that there is greater than 90 percent likelihood that people are causing global warming. (IPCC, 2007)
These latest findings amplify what other highly respected science organizations say:
In a joint statement with 10 other National Academies of Science, the U.S. National Academy of Sciences said:
"The scientific understanding of climate change is now sufficiently clear to justify nations taking prompt action. It is vital that all nations identify cost-effective steps that they can take now, to contribute to substantial and long-term reduction in net global greenhouse gas emissions."—Joint Statement of Science Academies: Global Response to Climate Change, 2005
The American Geophysical Union, a respected organization comprising over 41,000 Earth and space scientists, wrote in its position on climate change that "natural influences cannot explain the rapid increase in global near-surface temperatures observed during the second half of the 20th century."
http://www.edf.org/page.cfm?tagID=35215&source=ggadgw35215&gclid=CLfrmMLVr6MCFRD75wod6FCM4Q
Levels of carbon dioxide in the atmosphere are higher today than at any time in measurable history.
A study published in the journal Science reports that the current level of carbon dioxide (CO2) in the atmosphere — about 390 parts per million — is higher today than at any time in measurable history — at least the last 2.1 million years. Previous peaks of CO2 were never more than 300 ppm over the past 800,000 years, and the concentration is rising by around 2 ppm each year.
http://www.edf.org/article.cfm?contentID=10717
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