Global warming is the observed increase in the average temperature of the Earth's atmosphere and oceans in recent decades.
The Earth's average near-surface atmospheric temperature rose 0.6 ± 0.2 °Celsius (1.1 ± 0.4 °Fahrenheit) in the 20th century. The prevailing scientific opinion on climate change is that "most of the warming observed over the last 50 years is attributable to human activities"[1].
The increased amounts of carbon dioxide (CO2) and other greenhouse gases (GHGs) are the primary causes of the human-induced component of warming[2]. They are released by the burning of fossil fuels, land clearing and agriculture, etc. and lead to an increase in the greenhouse effect. The first speculation that a greenhouse effect might occur was by the Swedish chemist Svante Arrhenius in 1897, although it did not become a topic of popular debate until some 90 years later. [3]
The measure of the response to increased GHGs, and other anthropogenic and natural climate forcings, is climate sensitivity. It is found by observational [4] and model studies. This sensitivity is usually expressed in terms of the temperature response expected from a doubling of CO2 in the atmosphere. The current literature estimates sensitivity in the range 1.5–4.5 °C (2.7–8.1 °F). Models referenced by the Intergovernmental Panel on Climate Change (IPCC) project that global temperatures might increase between 1.4 and 5.8 °C (2.5 to 10.5 °F) between 1990 and 2100. The uncertainty in this range results from both the difficulty of estimating the volume of future greenhouse gas emissions and uncertainty about climate sensitivity.
An increase in global temperatures can in turn cause other changes, including a rising sea level and changes in the amount and pattern of precipitation. 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, glacial retreat, reduced summer stream flows, 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, warming (and sea level rise due to thermal expansion) is expected to continue past then, since CO2 has an estimated atmospheric lifetime of 50 to 200 years. [5]. Only a small minority of climate scientists discount the role that humanity's actions have played in recent warming. However, the uncertainty is more significant regarding how much climate change should be expected in the future, and there is a hotly contested political and public debate over what, if anything, should be done to reduce or reverse future warming, and how to deal with the predicted consequences.
2006-11-16 15:08:42
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answer #1
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answered by Anonymous
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The observable increase in temperatures, as others describe. While these inceases are documentable, how much of this is due to human activity remains the question - and therefore if modifying human activity can rectify things.
It is true that there have long-term temperature fluctuations on the planet, long before people existed. Through much of earth's history, for instance, there has been no ice pas as we know them; we have been in relative degrees of "ice age" for 10s or 100s of thousands of years.
But a full melt back to "normal" (whether humanity is to blame or not) would have serious impacts on the world as we know it: Say good-bye to Floridam Bangladesh, the Netherlands, and many other low-lying lands. As the human population continues to grow, we'll have more people to share less space, as well as the costs of relocating and rebuilding cities inland.
It also means more severe coastal storms - storms intensify over warmer water. Katrina could be the tip of the iceberg, so to speak.
So the question of how much human causes there are to global warming also add a follow-up? Can we really do anything to prevent it? If so, an ounce of prevention can be worth a pound of cure.
2006-11-17 03:07:22
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answer #2
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answered by kent_shakespear 7
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an increase in the average temperatures across the planet, phrased as 'Global Warming' it is that increase, but blamed on the human population, and extrapolated into the future to cause us to feel guilty and change our actions and attitudes.
The fact is that the planet has cycled through warm and cold periods throughout its history, long before Humans existed and will continue to do so long after we cease to do so. Human history is little more that 5000 years, and even less of that is written analysis of weather patterns. The dinosaurs lived here 65,000,000 years ago, and live was around long before them as well . that is less than 1/13,000th of the time and we forecasting forward assuming that what we have known is the normal status of this world.
2006-11-16 16:07:10
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answer #3
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answered by janssen411 6
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Global warming is the observed increase in the average temperature of the Earth's atmosphere and oceans in recent decades.
The Earth's average near-surface atmospheric temperature rose 0.6 ± 0.2 °Celsius (1.1 ± 0.4 °Fahrenheit) in the 20th century. The prevailing scientific opinion on climate change is that "most of the warming observed over the last 50 years is attributable to human activities".
The increased amounts of carbon dioxide (CO2) and other greenhouse gases (GHGs) are the primary causes of the human-induced component of warming[2]. They are released by the burning of fossil fuels, land clearing and agriculture, etc. and lead to an increase in the greenhouse effect. The first speculation that a greenhouse effect might occur was by the Swedish chemist Svante Arrhenius in 1897, although it did not become a topic of popular debate until some 90 years later. [3]
The measure of the response to increased GHGs, and other anthropogenic and natural climate forcings, is climate sensitivity. It is found by observational [4] and model studies. This sensitivity is usually expressed in terms of the temperature response expected from a doubling of CO2 in the atmosphere. The current literature estimates sensitivity in the range 1.5–4.5 °C (2.7–8.1 °F). Models referenced by the Intergovernmental Panel on Climate Change (IPCC) project that global temperatures might increase between 1.4 and 5.8 °C (2.5 to 10.5 °F) between 1990 and 2100. The uncertainty in this range results from both the difficulty of estimating the volume of future greenhouse gas emissions and uncertainty about climate sensitivity.
2006-11-16 16:55:29
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answer #4
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answered by Hally berry 3
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If you desire to obtain supply cash for local weather study, do you suppose that you can get a cheque should you say," I want the supply, as I suppose that I can end up that the figures that the present paradigm is situated upon are unsuitable" ? The first-class environmentalist, David Bellamy, has been silenced, and refused airtime. There continues to be no validated causative hyperlink among the volume of Co2 within the surroundings, and an expand in worldwide temperatures. The WWWF pics of the polar bears swimming had been taken within the Arctic summer time; while the ice cap in part melts, as they could not rise up to picture within the wintry weather. The ice used to be too thick! The East-Anglian uni study figures. "Oh! The figures do not fit our expectancies. Oh good. Keep quiet. Because we all know that we're proper." When the perception, and the religion is extra essential than squarely going through the reputable doubts of plenty of non supply-supported scientists, technology has been superceded through devout zealots. As Oliver Cromwell colourfully stated." I pray thee, within the bowels of Christ, recall that thou mayest be unsuitable."
2016-09-01 13:53:59
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answer #5
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answered by jordana 4
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are there actually ppl who still think global warming is a lie? yes democrats r evil n made up global warming(<---sarcasm), even though it is now scientific FACT. genius huh?
2006-11-16 16:27:04
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answer #6
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answered by Anonymous
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an increase in the earth's average atmospheric temperature that causes corresponding changes in climate and that may result from the greenhouse effect. greenhouse effect: 1. an atmospheric heating phenomenon, caused by short-wave solar radiation being readily transmitted inward through the earth's atmosphere but longer-wavelength heat radiation less readily transmitted outward, owing to its absorption by atmospheric carbon dioxide, water vapor, methane, and other gases; thus, the rising level of carbon dioxide is viewed with concern.
2. such a phenomenon on another planet.
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2006-11-16 15:18:44
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answer #7
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answered by tina 3
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A liberal myth concocted mostly be democrats so they can tell you what kind of car you are allowed to buy, what kind of deodorants and hairspray you can use, what kind of refrigerant you can use in your air conditioner, tax you to death, and otherwise control every move you make, make your life a living hell, just the way they like it.
2006-11-16 15:10:20
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answer #8
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answered by Anonymous
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