15 依依不捨
16 丟三落四
17 接二連三
18 一問三不知
2013年9月22日 星期日
2013年9月21日 星期六
Global Warming
Global Warming
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This article is about global warming changes. General discussion about the Earth changes , see " climate change ."
From 1958 Molao carbon dioxide content in the island
Ambient gas cycle diagram
U.S. a petrochemical plant exhaust
Global warming (global warming) refers to the period of time , the Earth's atmosphere and oceans rise in temperature due to the greenhouse effect caused by the climate change phenomenon , as one tragedy of the commons , and the effects they have caused global warming is called of effect .
In the 20th century , the global average temperature of the atmosphere near the ground rose 0.74 degrees Celsius . In general , the scientific community over the past 50 years found that climate change can be observed velocity is doubled over the past 100 years , so the inference that period the climate change driven by human activity .
Carbon dioxide and other greenhouse gases content continues to increase. It is the human factor in global warming, the main part . According to information , the atmospheric nitrous oxide (N20) content than the mid-18th century ( AD 1750 ) the industrial revolution began from 275ppbv to 310ppbv, carbon dioxide (CO2) levels increased from 280ppmv 360ppmv, methane ( CH4) from 700ppbv to 1720ppbv, this growth trend is mainly due to human activities . The burning of fossil fuels, forest clearing and farming , and so have enhanced greenhouse effect. Since 1950 , changes in solar radiation and volcanic activity produced by warming effect than human emissions of greenhouse gases even lower . These conclusions were more than 30 countries from the Group of Eight research groups recognized .
Scientists at the University of California, Hawaii, Central Pacific Ocean established on Mauna Loa peak 4 7 meters high and a 27 -meter-high tower sampling , sampling four times per hour , analyze the changes in carbon dioxide . ( At right )
The current global average temperature, carbon dioxide concentration changes with temperature rise , in fact, there is no direct relationship , from the industrial revolution , carbon dioxide levels increased dramatically, although the plant photosynthesis absorbs a large part of carbon dioxide dissolved in the ocean is also a part of carbon dioxide into calcium carbonate and fixed , but the content of carbon dioxide in the air is gradually increased. According to the American University of Virginia and the University of East Anglia joint research results in the latter half of the 20th century , global temperatures rising trend is very clear , the temperature changes shown below.
Global temperature increase to bring include rising sea levels and rainfall and snowfall in amount and style on the changes. These changes may induce stronger and more frequent extreme weather events , such as floods, droughts , heat waves , hurricanes and tornadoes. In addition, there are other consequences, including higher or lower agricultural yields, glacier retreat, reduced summer river flows , species extinction and rampant diseases . Events due to global warming is expected to cause the number and intensity ; these special events , but it is difficult to connect to the global warming. Because carbon dioxide in the atmosphere for 50 years to 200 years of life , many studies focused on or before time 2100 . But whatever the causes of climate change, or the outcome, many people are very concerned about ; but also for the consequences of policies to meet predicted how to implement , causing a wide range of global political debate , public debate and a variety of academic research . These policy discussions focus should reduce or reverse future warming and how to meet the anticipated consequences.
Contents
A nomenclature
Nomenclature
In principle, the " global warming " the word on the cause of neutral point of view , but according to popular usage, " global warming " means that the human impact on the environment . Other organizations use the " anthropogenic climate change " (anthropogenic climate change) representative of the factors leading to change.
The history of global warming
Depending on the reorganization of the show in the past in 2000 , the average surface temperature . Every ten years to find an average. Special show 2004 the temperature reference.
According to the instrumental record , relative to the 1860-1900 period, the global land and ocean temperature has increased by 0.75 degrees Celsius . Since 1979 , land temperatures rise faster than twice as fast as ocean temperatures ( land temperature has increased by 0.25 degrees Celsius , while the ocean temperature has increased by 0.13 degrees Celsius ) . According to satellite temperature detection , tropospheric temperature 0.12 degrees Celsius per decade rise to 0.22 degrees . In 1850 twelve thousand years ago , although there have Medieval Warm Period and Little Ice Age , but the public believe that global temperatures are relatively stable .
According to the U.S. National Aeronautics and Space Administration 's Goddard Institute for Space Studies research report estimated that since the 1800s there began measuring instrument widely used in 2005, the Earth has a temperature second warmest year since records began , more than 1998 annual average record low surface temperature of 0.06 degrees Celsius. World Meteorological Organization and the UK Climate Research Unit has a similar estimate was expected in 2005 is second only to 1998 second warmest year .
In the modern history of mankind have several temperature records. These records are from different places, accuracy and reliability are not the same. In 1860 global temperatures have similar instrumental record , I believe that when the records are rarely urban heat island effect . From the recent multi- year record millennium show the long-term outlook , the temperature for the past 1000 records can be seen in the discussions of the differences . The last 50 years, the process of climate change is very clear , thanks to detailed temperature records. By 1979 , humans have started to use satellite temperature measurements to measure the temperature of the troposphere .
In 2000 , the local high temperature records are often broken. For example : 11 August 2003 , the town of Logrono Rui Shige recorded 41.5 degrees Celsius , breaking the 139 years of records. In the same year , on August 10 , London, England the temperature reached 38.1 degrees Celsius , breaking the 1990 record. Meanwhile, south of Paris at night minimum temperature measured at 25.5 degrees Celsius , breaking the record since 1873 . August 7 at night , Germany also broke the centuries maximum temperature records. In the summer of 2003 , Taipei, Shanghai , Hangzhou, Wuhan, Fuzhou local high temperature records were broken , and more quickly , Zhejiang Province, China repeatedly breaking high temperatures recorded 67 weather stations in 40 to refresh records. July 2004 , Guangzhou rare high temperature broke the record of 53 years . July 2005 , the United States has two hundred cities have hit a historic high temperature records. August 16, 2006 , China Chongqing highest temperature up to 43 degrees . Yilan, Taiwan in July 8, 2006 temperatures up to 38.8 degrees , breaking the 1997 record. August 16, 2007 , Saitama, Japan Kumagaya temperatures up to 40.9 degrees , breaking the 1933 record of Yamagata, Japan .
Genesis
See also: Recent climate change causes and scientific views of climate change
Carbon dioxide levels over the past 40 years since the industrial revolution and the rapid surge ; cyclical changes in the Earth's orbit ( also known as Milankovitch cycles ) is believed to be one hundred thousand years behind the ice age cycle promoters .
Changes in the climate system from natural or internal operations and external changes to the power response . These external forces include the human and non-human factors, such as solar activity , volcanic activity and greenhouse gases. More than climatologists agree that the earth has been warming in recent years . Modern causes of climate change is still active research areas , but the scientific consensus that the greenhouse gases are the main cause of global warming . However, outside of the scientific community is still disputed this conclusion .
In the Earth's atmosphere of carbon dioxide and methane emissions , while other things equal , will lead to the ground warming, greenhouse gases natural greenhouse effect. Without it, the Earth's temperature will be 30 degrees Celsius lower than it is now , the planet is not fit for human habitation . Therefore, in the supporting and opposing arguments between this warming theory is incorrect , but should focus on the atmosphere of carbon dioxide and methane content increases arising from the final results, what time or what should be promoted when it agreed to make ease .
For an example of an important feedback process is ice- albedo feedback. Increase in carbon dioxide in the atmosphere warming the Earth's surface , causing polar ice caps to dissolve. Land and open water to occupy more places . Both even less reflective than ice , so absorb more solar radiation . This makes warming intensifies, the end result in more ice melts , circulating constantly sustained .
Because the earth's thermal inertia and other indirect effects on the slow response of the Earth's climate in today's ever-increasing greenhouse gases under become unbalanced . Climate behavioral studies indicate that even maintain current levels of greenhouse gases , the global average temperature rise may still be 0.5 to 1 degree Celsius .
Greenhouse gases in the atmosphere
In the past 65 years , atmospheric carbon dioxide and global temperature charts
1980 to 2003 , the world's major greenhouse gas trends
Fuels emissions from comparison
Greenhouse gases shortwave radiation of the sun is transparent. However, they are absorbed from the earth has issued ( blackbody radiation ) part of the long-wave infrared radiation. This makes difficult to cool the planet . They can be based on how much warming the Earth as an indicator of global warming potential .
Atmospheric concentrations of carbon dioxide and methane since 1750 than pre-industrial levels ( 280 ppm ) were increased by 31% and 149% . And now the level has been higher than 380 parts per million . Ice cores extracted from reliable data that in the past 65 million years for comparison , this is a significant surge . From some non- direct geological evidence , reason to believe that carbon dioxide levels over the past 4000 years is relatively high . In the past 20 years , about three-quarters of all man-made carbon dioxide emissions from burning fossil fuels. Other anthropogenic emissions are land use, especially deforestation .
Big Island of Hawaii in 1958, about 3,400 meters above sea level Mauna Loa on the mixing ratio of carbon dioxide launched the longest continuous measurement instrument . From then on, it was found that the measurement results annually rising as Keeling curve (Keeling Curve) shows that the value from the original 315 ppm up to 2006 more than 380 parts per million , an increase of about 21%. showed that carbon dioxide levels in the month mild seasonal changes throughout the year as a whole is on the rise.
Methane is the main component of natural gas , most of the biological production and from natural gas pipelines and other infrastructure leak out. Some methane is natural biological sources , such as termites. But other sources are caused by human -driven increase in agricultural activities , such as rice farming. Recent evidence shows that the forest may be a source of methane . If true, this would be an additional contribution to the natural greenhouse effect , rather than man-made greenhouse effect .
Although the actual trajectory depends on the trend of uncertain economic , social , technological and natural development , expected future level of carbon dioxide because of the use of fossil fuels will continue to rise . The Intergovernmental Panel on Climate Change , " a special report emissions " of carbon dioxide set out the many different circumstances in 2100 can be achieved by the 541-970 ppm level. If the coal and tar are widely adopted , the existing reserves of fossil fuels is the ability to achieve this level in 2100 and continued after discharge .
In 2000 anthropogenic emissions of greenhouse gases of the various components
Major global anthropogenic emissions of greenhouse gases from burning fuels. Most of the rest comes from " short fuels" ( production and delivery of fuel consumed ) , industrial and agricultural body increased. Production emissions. In 1990 , their proportion was 5.8% , 5.2 % and 3.3% . The current data are available for comparison. About 17 % of the fuel consumed by power generation . Few from nature and man-made biological sources , only about 6.3% of methane generated from agriculture and nitrous oxide .
Positive feedback effect will lead to more sources of greenhouse gases . For example, from the Siberian permafrost peat bog in the release of methane may be as many as 7 million tons. Note that human emissions of pollutants such as sulphate aerosols have a cooling effect . Although disturbed the natural cycle of the mid- twentieth century may result seen in the plateau temperature record , but those human emissions of pollutants in a certain extent, also lead to similar temperature record
Trends in atmospheric carbon dioxide concentration studies
By discussing the existing 60 years ( 1948 to 2008 ) of atmospheric carbon dioxide (CO2) concentration data (From reports of Pieter Tans. Etal) the distribution , using trend analysis , given the specific trends in equation form . And ice core analysis or observational data comparison results show that the equation of the curve trend in line with the existing data , and then from 2010 to 2016 are given between atmospheric CO2 concentrations predicted value (389 ~ 402ppmv), and thus the concentration of CO2 and climate change relationship to be a preliminary study .
Without the greenhouse effect, people can not survive. Just make greenhouse gas carbon dioxide increases .
Other theories
Mankind has attempted to measure concerning "Over the past 50 years, the majority of observed warming is caused by human activity ," the degree of scientific consensus . in the journal Science , the University of California, San Diego history professor Naomi · Ole Velazquez secret information from the scientific institutions in 928 parts of the scientific literature to find a summary of global climate change (global climate change). He concluded , express or implied, of which 75% accepted this view of public opinion . However, Professor Ole Velazquez indicated in the summary did not say how many human-induced warming effect .
In addition to this public opinion , there are other hypotheses to try to explain all or part of the causes of the rise in global temperatures . Some hypotheses are as follows:
Global temperatures is still a natural temperature variation range.
Global temperatures is a small ice age to come.
The reason is that the global temperature changes in solar radiation and cloud cover moderating effect .
Global temperature rise is a reflection of urban heat island effect . Because many readings are in densely populated areas or are expanding .
Solar variation theory
Over the past 30 years, changes in solar radiation map
Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report elaborated model of the last 40 to 50 years found that climate change does not require changes in solar luminosity . These findings volcanic and solar activity can affect only 1,950 years ago, half the temperature changes , but this has recently been offset by the forces of nature . In particular, since the 1750 greenhouse gas driven climate change over the same period increased solar activity driven eight times higher .
Some studies (Lean et al , 2002 ; Wang et al , 2005 ) that the pre-industrial era solar luminosity than the third assessment report referred to in the recovery record ( for example : Hoyt and Schatten, 1993年; Lean, 2000 ) is also three to four times less . Other researchers believe that the sun luminosity effects on global warming has been underestimated. They estimate that solar activity has recently prompted 16% of the greenhouse effect , or 36%. Others it is recommended that clouds and other feedback processes exacerbated by changes in solar activity impact . If that is true , changes in solar activity really been underestimated. From the general scientific understanding, solar luminosity changes on historical contribution to climate change is very small .
Now the level of solar activity is historically high . Scientist Sami Suolan Ji (Sami Solanki) Dr. think the last 60 years to 70 years, solar activity is eight thousand years of the peak. Muscheler and others that have occurred over the past few years are similar to the peak period . Solanki Dr decided on the basis of their analysis of solar activity in the next 50 years will reduce the chance rate is about 92%. Furthermore, researchers at Duke University in 2005 found that over the past two decades of change in the 10 to 30 percent may come from the increased output of the sun . reviewed the existing literature , Foukal et al concluded that since the mid-1970s, changes in solar output is difficult to exacerbate global warming and there is no evidence to suggest that the luminosity of the sun during this period increased.
Vegetation, forest resources and global warming relations
Global forest resources are effective tools for preventing global warming . Through photosynthesis, trees absorb carbon dioxide in air to produce oxygen and sugar . When humans are part of forest destruction will be used as a fuel for heating or firing into a wood . In the use of the combustion process produces carbon dioxide , increasing the content of carbon dioxide in the atmosphere , further aggravating the greenhouse effect, accelerating global warming . Thus, on the one hand reduce the absorption of carbon dioxide, a major greenhouse gas quantity , on the other hand will increase carbon dioxide emissions. So break or unreasonable use of forest resources, resources are severely damaged the environment , global warming is a major incentive . a large area of grassland and vegetation to absorb carbon dioxide and also has the function of groundwater conservation , grassland and vegetation severely damaged areas will also cause severe sandstorms, accelerating desertification of grassland and vegetation .
Moral , social and political controversies
See also: Global warming controversy
Over the past few years, public awareness of global warming and the degree of attention improved significantly. people to the cause of global warming and the scientific explanation of attention , but caused a political and economic debate. Although poor areas , especially in Africa is very small emissions , but face significant risks arising from global warming . Meanwhile, the U.S. dissatisfaction with developing countries to relieve the constraints of the Kyoto Protocol , and use this as a reason to refuse to sign the agreement . In Western society, compared to the U.S. , Europe has a lot of people to accept the human influence on climate warming and efforts to fight these allegations .
Organizations and companies such as fossil fuels by Philip Cooney (Philip Cooney) , and some think tanks - Competitive Enterprise Institute and the Cato Institute, represented by the American Petroleum Institute and Exxon Mobil to use some exercise to dilute the risks of global warming . Environmental groups and public figures , it held campaign to emphasize the risk of them . Recently, some companies have reduced fossil fuel desalination movement , and even called for a policy to avoid global warming .
Restrictions on this issue spurs industrial greenhouse gas emissions impact on economic activity debate . In the United States , and reports of the scientific evidence for political manipulation has become an important issue. Other states will most likely discuss the reduction to be taken when other more clean energy cost required .
Others focus of debate lies in some of the newly industrialized countries such as India and China in efforts to curb emissions should be how much. 2007 , China 's carbon dioxide emissions have overtaken the United States , China argues that because China's per capita emissions are one-third of the United States ( 2010 ) , so there is no great responsibility in reducing emissions . United States argued that if they bear the necessary abatement costs , China also . India will soon become one of the big industrial emissions will be the same with China facing the same problem .
Impact
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Please help by adding reliable sources multifaceted improve this article .
Main article: Effects of global warming
By the effects of global warming , in the Swiss Alps, the Aletsch glacier is constantly Back
One thousand years the Northern Hemisphere temperature trends ( 1000 - 1950 degrees per minute 50 years per decade 1950-2000 moment degrees )
As ocean temperatures , sea water volume expansion , the Antarctic and Greenland continental glacier melt will accelerate , leading to rising sea levels will submerge low-lying coastal areas, such as Oceania islands Tuvalu have been flooded . Worldwide there are 3 /4 of the population live in less than 500 km from the coast where the land area is reduced greatly affect human living environment , and may even lead to war . River seawall establishment , can reduce the impact of rising sea levels and protect low-lying areas . ( Note that the widely circulated " floating on the oceans and melting of glaciers and sea level rise " argument is wrong. According to Archimedes' principle , in fact , melting glaciers floating on the ocean sea levels will remain after unchanged only when the land into the ocean after melting glaciers will change sea level )
As ocean temperatures , water evaporates faster, a lot of water vapor is transported into the atmosphere will lead to a sudden increase in rainfall in some areas within a short time , so that heavy rain will cause flooding, landslides, mudslides and other more frequent occurrence in the city is located along the river and the river downstream of the vast region therefore subject to flooding , flood area because of short-term and rapid expansion of heavy precipitation , soil erosion problems are more severe than in the past .
As atmospheric temperature, resulting in proliferation of tropical infectious diseases to high latitudes , there are already signs of the spread of tropical diseases . In the past, at low temperatures, the virus is difficult to survive winter temperatures rise as there may be activities throughout the year , the most recent monitoring found that in the past has been the control of diseases such as tuberculosis , which are likely to break out again .
As atmospheric temperature increases, so evaporation rise in the previous drought areas face a more severe test without proper farming methods is likely to allow previously vegetated semi-arid areas unprotected become semi-desert region , which resulted in the accelerated desertification land areas , deserts expand danger ( in fact desertification problem has plagued East and Central Asian countries , in the Sahara border region is worrying situation ) .
As temperature increases, if the top of the food chain in the upper layer and the corresponding changes in biological if it will not make a serious crisis to breeding populations and development of the entire biological diversity will be threatened, many species will accelerate the pace of extinction .
As polar ice collapses , Scandinavia, South America, near-polar where the temperature will drop rapidly ( due to ice melt has melted latent heat , a lot of ice also melts will absorb a lot of energy for melting , and therefore the near-polar where the temperature will drop rapidly ) , will seriously affect the local ecosystem , causing irreversible changes.
Australia epidemiologist Antonio McMichael (Anthony McMichael) in the American Society for Microbiology 's meeting warned that global warming makes a variety of epidemic outbreak of epidemic mode change to increase opportunities .
Due to extreme weather causes crop failure , reduced food supplies in some areas causing serious economic losses, and even lead to famine , such as droughts cause desertification in Africa, to expand the scope of agricultural land decreased productivity .
Other views on global warming
(※ The views are independent )
In fact , the Earth 4.6 billion years ago, continue to experience the cold of global warming , sea level rise and fall, when carbon dioxide levels are high and sometimes low , and some times even much higher than the current level , not fixed . Since the air temperature, sea level , carbon dioxide levels are constantly changing, and the most recent decades temperature , sea level and changes in the level of carbon dioxide in the natural range of variation completely . Now " prevent global warming " in trying to make the Earth's temperature behavior to maintain a certain violation of the laws of nature .
" Average temperature " , the temperature should be what age is ambiguous as standard , not to mention billions of years of Earth's history, nearly two thousand years of human history , there have been Medieval Warm Period and Little Ice Age both average temperature extreme opposite situation , in the absence of criteria for determining what temperature is considered unreasonable to talk about preventing global warming .
Sea level in the tens of thousands of years has been on the rise , with little human activity . Initially, Asia and the Americas , Japan, Taiwan and the Asian continent , the United Kingdom and continental Europe are linked together , and later was only separated from sea level rise , so will sea level rise is mainly attributable to human inappropriate, is the lack of scientific knowledge embodied .
" Carbon " and " prevent global warming " and other slogans actually become political show, signed the " Kyoto Protocol" countries do not actively saving, and even increased . ( See the relevant chapter Kyoto Protocol ) make people suspect it is the politicians in order to scare up votes means.
Some countries in order to " prevent global warming " as the name of levying various taxes , increasing national burden , so that the original line of the population living in poverty is more poverty. These countries do not focus on improving technology to reduce carbon emissions but seeking only to collect taxes , attracting people's criticism. So that people suspected " global warming " is a multi- government to collect taxes from the people who deliberately exaggerated.
Business benefits: Many businesses put " low carbon " as a propaganda tool , and low-carbon products are often more expensive than other products , if forced to give up ordinary products and switched to a low-carbon products will increase the burden on the poor is immoral .
Some claimed to be able to reduce greenhouse gas emissions approach , in fact it will increase greenhouse gas emissions , such as biofuels ; while the effect of planting is suspected because of this process and the plant itself greenhouse gas emissions may be higher than it could be effective in reducing more greenhouse gas emissions .
According to chemical principles , " lights a candle " actually emit more carbon . Therefore, the "Earth Hour " lights a candle in fact, many people with their carbon reduction claims contrary , show more ingredients .
So that those who died in the cold wave to reduce global warming , said to refer to the heat wave killed more people than cold . Some people think that global warming makes the high latitudes in summer hotter , colder winter climate extremes often occur . But in fact , the occurrence of cold wave is just proof of global warming the earth did not happen . Moreover, warming , cooling blame global warming is clearly an unscientific irrational , contrary to the scientific principle of falsifiability .
2013 Arctic summer cover area than in 2012 increased by 60 % over one million square miles. Scientists warned that the world is experiencing rapid decline in temperature , may face global cooling . Temperatures will continue to drop rapidly after the middle of this century . According to the computer before this catastrophic climate warming is predicted dangerously misleading
Wikipedia , the free encyclopedia
This entry need to be proficient or familiar with this topic and assistance of professionals involved in editing.
Please invite suitable individuals to assist or reference to the relevant professional literature , self- improvement this entry. More details and entry details , see the talk page .
Globe icon
This entry has only part of the area of the information or opinions , can not be done and the full expression of the universal common area contains extensive information and perspectives .
Please help supplement the content in order to avoid bias , or discuss this issue.
This article is about global warming changes. General discussion about the Earth changes , see " climate change ."
From 1958 Molao carbon dioxide content in the island
Ambient gas cycle diagram
U.S. a petrochemical plant exhaust
Global warming (global warming) refers to the period of time , the Earth's atmosphere and oceans rise in temperature due to the greenhouse effect caused by the climate change phenomenon , as one tragedy of the commons , and the effects they have caused global warming is called of effect .
In the 20th century , the global average temperature of the atmosphere near the ground rose 0.74 degrees Celsius . In general , the scientific community over the past 50 years found that climate change can be observed velocity is doubled over the past 100 years , so the inference that period the climate change driven by human activity .
Carbon dioxide and other greenhouse gases content continues to increase. It is the human factor in global warming, the main part . According to information , the atmospheric nitrous oxide (N20) content than the mid-18th century ( AD 1750 ) the industrial revolution began from 275ppbv to 310ppbv, carbon dioxide (CO2) levels increased from 280ppmv 360ppmv, methane ( CH4) from 700ppbv to 1720ppbv, this growth trend is mainly due to human activities . The burning of fossil fuels, forest clearing and farming , and so have enhanced greenhouse effect. Since 1950 , changes in solar radiation and volcanic activity produced by warming effect than human emissions of greenhouse gases even lower . These conclusions were more than 30 countries from the Group of Eight research groups recognized .
Scientists at the University of California, Hawaii, Central Pacific Ocean established on Mauna Loa peak 4 7 meters high and a 27 -meter-high tower sampling , sampling four times per hour , analyze the changes in carbon dioxide . ( At right )
The current global average temperature, carbon dioxide concentration changes with temperature rise , in fact, there is no direct relationship , from the industrial revolution , carbon dioxide levels increased dramatically, although the plant photosynthesis absorbs a large part of carbon dioxide dissolved in the ocean is also a part of carbon dioxide into calcium carbonate and fixed , but the content of carbon dioxide in the air is gradually increased. According to the American University of Virginia and the University of East Anglia joint research results in the latter half of the 20th century , global temperatures rising trend is very clear , the temperature changes shown below.
Global temperature increase to bring include rising sea levels and rainfall and snowfall in amount and style on the changes. These changes may induce stronger and more frequent extreme weather events , such as floods, droughts , heat waves , hurricanes and tornadoes. In addition, there are other consequences, including higher or lower agricultural yields, glacier retreat, reduced summer river flows , species extinction and rampant diseases . Events due to global warming is expected to cause the number and intensity ; these special events , but it is difficult to connect to the global warming. Because carbon dioxide in the atmosphere for 50 years to 200 years of life , many studies focused on or before time 2100 . But whatever the causes of climate change, or the outcome, many people are very concerned about ; but also for the consequences of policies to meet predicted how to implement , causing a wide range of global political debate , public debate and a variety of academic research . These policy discussions focus should reduce or reverse future warming and how to meet the anticipated consequences.
Contents
A nomenclature
Nomenclature
In principle, the " global warming " the word on the cause of neutral point of view , but according to popular usage, " global warming " means that the human impact on the environment . Other organizations use the " anthropogenic climate change " (anthropogenic climate change) representative of the factors leading to change.
The history of global warming
Depending on the reorganization of the show in the past in 2000 , the average surface temperature . Every ten years to find an average. Special show 2004 the temperature reference.
According to the instrumental record , relative to the 1860-1900 period, the global land and ocean temperature has increased by 0.75 degrees Celsius . Since 1979 , land temperatures rise faster than twice as fast as ocean temperatures ( land temperature has increased by 0.25 degrees Celsius , while the ocean temperature has increased by 0.13 degrees Celsius ) . According to satellite temperature detection , tropospheric temperature 0.12 degrees Celsius per decade rise to 0.22 degrees . In 1850 twelve thousand years ago , although there have Medieval Warm Period and Little Ice Age , but the public believe that global temperatures are relatively stable .
According to the U.S. National Aeronautics and Space Administration 's Goddard Institute for Space Studies research report estimated that since the 1800s there began measuring instrument widely used in 2005, the Earth has a temperature second warmest year since records began , more than 1998 annual average record low surface temperature of 0.06 degrees Celsius. World Meteorological Organization and the UK Climate Research Unit has a similar estimate was expected in 2005 is second only to 1998 second warmest year .
In the modern history of mankind have several temperature records. These records are from different places, accuracy and reliability are not the same. In 1860 global temperatures have similar instrumental record , I believe that when the records are rarely urban heat island effect . From the recent multi- year record millennium show the long-term outlook , the temperature for the past 1000 records can be seen in the discussions of the differences . The last 50 years, the process of climate change is very clear , thanks to detailed temperature records. By 1979 , humans have started to use satellite temperature measurements to measure the temperature of the troposphere .
In 2000 , the local high temperature records are often broken. For example : 11 August 2003 , the town of Logrono Rui Shige recorded 41.5 degrees Celsius , breaking the 139 years of records. In the same year , on August 10 , London, England the temperature reached 38.1 degrees Celsius , breaking the 1990 record. Meanwhile, south of Paris at night minimum temperature measured at 25.5 degrees Celsius , breaking the record since 1873 . August 7 at night , Germany also broke the centuries maximum temperature records. In the summer of 2003 , Taipei, Shanghai , Hangzhou, Wuhan, Fuzhou local high temperature records were broken , and more quickly , Zhejiang Province, China repeatedly breaking high temperatures recorded 67 weather stations in 40 to refresh records. July 2004 , Guangzhou rare high temperature broke the record of 53 years . July 2005 , the United States has two hundred cities have hit a historic high temperature records. August 16, 2006 , China Chongqing highest temperature up to 43 degrees . Yilan, Taiwan in July 8, 2006 temperatures up to 38.8 degrees , breaking the 1997 record. August 16, 2007 , Saitama, Japan Kumagaya temperatures up to 40.9 degrees , breaking the 1933 record of Yamagata, Japan .
Genesis
See also: Recent climate change causes and scientific views of climate change
Carbon dioxide levels over the past 40 years since the industrial revolution and the rapid surge ; cyclical changes in the Earth's orbit ( also known as Milankovitch cycles ) is believed to be one hundred thousand years behind the ice age cycle promoters .
Changes in the climate system from natural or internal operations and external changes to the power response . These external forces include the human and non-human factors, such as solar activity , volcanic activity and greenhouse gases. More than climatologists agree that the earth has been warming in recent years . Modern causes of climate change is still active research areas , but the scientific consensus that the greenhouse gases are the main cause of global warming . However, outside of the scientific community is still disputed this conclusion .
In the Earth's atmosphere of carbon dioxide and methane emissions , while other things equal , will lead to the ground warming, greenhouse gases natural greenhouse effect. Without it, the Earth's temperature will be 30 degrees Celsius lower than it is now , the planet is not fit for human habitation . Therefore, in the supporting and opposing arguments between this warming theory is incorrect , but should focus on the atmosphere of carbon dioxide and methane content increases arising from the final results, what time or what should be promoted when it agreed to make ease .
For an example of an important feedback process is ice- albedo feedback. Increase in carbon dioxide in the atmosphere warming the Earth's surface , causing polar ice caps to dissolve. Land and open water to occupy more places . Both even less reflective than ice , so absorb more solar radiation . This makes warming intensifies, the end result in more ice melts , circulating constantly sustained .
Because the earth's thermal inertia and other indirect effects on the slow response of the Earth's climate in today's ever-increasing greenhouse gases under become unbalanced . Climate behavioral studies indicate that even maintain current levels of greenhouse gases , the global average temperature rise may still be 0.5 to 1 degree Celsius .
Greenhouse gases in the atmosphere
In the past 65 years , atmospheric carbon dioxide and global temperature charts
1980 to 2003 , the world's major greenhouse gas trends
Fuels emissions from comparison
Greenhouse gases shortwave radiation of the sun is transparent. However, they are absorbed from the earth has issued ( blackbody radiation ) part of the long-wave infrared radiation. This makes difficult to cool the planet . They can be based on how much warming the Earth as an indicator of global warming potential .
Atmospheric concentrations of carbon dioxide and methane since 1750 than pre-industrial levels ( 280 ppm ) were increased by 31% and 149% . And now the level has been higher than 380 parts per million . Ice cores extracted from reliable data that in the past 65 million years for comparison , this is a significant surge . From some non- direct geological evidence , reason to believe that carbon dioxide levels over the past 4000 years is relatively high . In the past 20 years , about three-quarters of all man-made carbon dioxide emissions from burning fossil fuels. Other anthropogenic emissions are land use, especially deforestation .
Big Island of Hawaii in 1958, about 3,400 meters above sea level Mauna Loa on the mixing ratio of carbon dioxide launched the longest continuous measurement instrument . From then on, it was found that the measurement results annually rising as Keeling curve (Keeling Curve) shows that the value from the original 315 ppm up to 2006 more than 380 parts per million , an increase of about 21%. showed that carbon dioxide levels in the month mild seasonal changes throughout the year as a whole is on the rise.
Methane is the main component of natural gas , most of the biological production and from natural gas pipelines and other infrastructure leak out. Some methane is natural biological sources , such as termites. But other sources are caused by human -driven increase in agricultural activities , such as rice farming. Recent evidence shows that the forest may be a source of methane . If true, this would be an additional contribution to the natural greenhouse effect , rather than man-made greenhouse effect .
Although the actual trajectory depends on the trend of uncertain economic , social , technological and natural development , expected future level of carbon dioxide because of the use of fossil fuels will continue to rise . The Intergovernmental Panel on Climate Change , " a special report emissions " of carbon dioxide set out the many different circumstances in 2100 can be achieved by the 541-970 ppm level. If the coal and tar are widely adopted , the existing reserves of fossil fuels is the ability to achieve this level in 2100 and continued after discharge .
In 2000 anthropogenic emissions of greenhouse gases of the various components
Major global anthropogenic emissions of greenhouse gases from burning fuels. Most of the rest comes from " short fuels" ( production and delivery of fuel consumed ) , industrial and agricultural body increased. Production emissions. In 1990 , their proportion was 5.8% , 5.2 % and 3.3% . The current data are available for comparison. About 17 % of the fuel consumed by power generation . Few from nature and man-made biological sources , only about 6.3% of methane generated from agriculture and nitrous oxide .
Positive feedback effect will lead to more sources of greenhouse gases . For example, from the Siberian permafrost peat bog in the release of methane may be as many as 7 million tons. Note that human emissions of pollutants such as sulphate aerosols have a cooling effect . Although disturbed the natural cycle of the mid- twentieth century may result seen in the plateau temperature record , but those human emissions of pollutants in a certain extent, also lead to similar temperature record
Trends in atmospheric carbon dioxide concentration studies
By discussing the existing 60 years ( 1948 to 2008 ) of atmospheric carbon dioxide (CO2) concentration data (From reports of Pieter Tans. Etal) the distribution , using trend analysis , given the specific trends in equation form . And ice core analysis or observational data comparison results show that the equation of the curve trend in line with the existing data , and then from 2010 to 2016 are given between atmospheric CO2 concentrations predicted value (389 ~ 402ppmv), and thus the concentration of CO2 and climate change relationship to be a preliminary study .
Without the greenhouse effect, people can not survive. Just make greenhouse gas carbon dioxide increases .
Other theories
Mankind has attempted to measure concerning "Over the past 50 years, the majority of observed warming is caused by human activity ," the degree of scientific consensus . in the journal Science , the University of California, San Diego history professor Naomi · Ole Velazquez secret information from the scientific institutions in 928 parts of the scientific literature to find a summary of global climate change (global climate change). He concluded , express or implied, of which 75% accepted this view of public opinion . However, Professor Ole Velazquez indicated in the summary did not say how many human-induced warming effect .
In addition to this public opinion , there are other hypotheses to try to explain all or part of the causes of the rise in global temperatures . Some hypotheses are as follows:
Global temperatures is still a natural temperature variation range.
Global temperatures is a small ice age to come.
The reason is that the global temperature changes in solar radiation and cloud cover moderating effect .
Global temperature rise is a reflection of urban heat island effect . Because many readings are in densely populated areas or are expanding .
Solar variation theory
Over the past 30 years, changes in solar radiation map
Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report elaborated model of the last 40 to 50 years found that climate change does not require changes in solar luminosity . These findings volcanic and solar activity can affect only 1,950 years ago, half the temperature changes , but this has recently been offset by the forces of nature . In particular, since the 1750 greenhouse gas driven climate change over the same period increased solar activity driven eight times higher .
Some studies (Lean et al , 2002 ; Wang et al , 2005 ) that the pre-industrial era solar luminosity than the third assessment report referred to in the recovery record ( for example : Hoyt and Schatten, 1993年; Lean, 2000 ) is also three to four times less . Other researchers believe that the sun luminosity effects on global warming has been underestimated. They estimate that solar activity has recently prompted 16% of the greenhouse effect , or 36%. Others it is recommended that clouds and other feedback processes exacerbated by changes in solar activity impact . If that is true , changes in solar activity really been underestimated. From the general scientific understanding, solar luminosity changes on historical contribution to climate change is very small .
Now the level of solar activity is historically high . Scientist Sami Suolan Ji (Sami Solanki) Dr. think the last 60 years to 70 years, solar activity is eight thousand years of the peak. Muscheler and others that have occurred over the past few years are similar to the peak period . Solanki Dr decided on the basis of their analysis of solar activity in the next 50 years will reduce the chance rate is about 92%. Furthermore, researchers at Duke University in 2005 found that over the past two decades of change in the 10 to 30 percent may come from the increased output of the sun . reviewed the existing literature , Foukal et al concluded that since the mid-1970s, changes in solar output is difficult to exacerbate global warming and there is no evidence to suggest that the luminosity of the sun during this period increased.
Vegetation, forest resources and global warming relations
Global forest resources are effective tools for preventing global warming . Through photosynthesis, trees absorb carbon dioxide in air to produce oxygen and sugar . When humans are part of forest destruction will be used as a fuel for heating or firing into a wood . In the use of the combustion process produces carbon dioxide , increasing the content of carbon dioxide in the atmosphere , further aggravating the greenhouse effect, accelerating global warming . Thus, on the one hand reduce the absorption of carbon dioxide, a major greenhouse gas quantity , on the other hand will increase carbon dioxide emissions. So break or unreasonable use of forest resources, resources are severely damaged the environment , global warming is a major incentive . a large area of grassland and vegetation to absorb carbon dioxide and also has the function of groundwater conservation , grassland and vegetation severely damaged areas will also cause severe sandstorms, accelerating desertification of grassland and vegetation .
Moral , social and political controversies
See also: Global warming controversy
Over the past few years, public awareness of global warming and the degree of attention improved significantly. people to the cause of global warming and the scientific explanation of attention , but caused a political and economic debate. Although poor areas , especially in Africa is very small emissions , but face significant risks arising from global warming . Meanwhile, the U.S. dissatisfaction with developing countries to relieve the constraints of the Kyoto Protocol , and use this as a reason to refuse to sign the agreement . In Western society, compared to the U.S. , Europe has a lot of people to accept the human influence on climate warming and efforts to fight these allegations .
Organizations and companies such as fossil fuels by Philip Cooney (Philip Cooney) , and some think tanks - Competitive Enterprise Institute and the Cato Institute, represented by the American Petroleum Institute and Exxon Mobil to use some exercise to dilute the risks of global warming . Environmental groups and public figures , it held campaign to emphasize the risk of them . Recently, some companies have reduced fossil fuel desalination movement , and even called for a policy to avoid global warming .
Restrictions on this issue spurs industrial greenhouse gas emissions impact on economic activity debate . In the United States , and reports of the scientific evidence for political manipulation has become an important issue. Other states will most likely discuss the reduction to be taken when other more clean energy cost required .
Others focus of debate lies in some of the newly industrialized countries such as India and China in efforts to curb emissions should be how much. 2007 , China 's carbon dioxide emissions have overtaken the United States , China argues that because China's per capita emissions are one-third of the United States ( 2010 ) , so there is no great responsibility in reducing emissions . United States argued that if they bear the necessary abatement costs , China also . India will soon become one of the big industrial emissions will be the same with China facing the same problem .
Impact
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Main article: Effects of global warming
By the effects of global warming , in the Swiss Alps, the Aletsch glacier is constantly Back
One thousand years the Northern Hemisphere temperature trends ( 1000 - 1950 degrees per minute 50 years per decade 1950-2000 moment degrees )
As ocean temperatures , sea water volume expansion , the Antarctic and Greenland continental glacier melt will accelerate , leading to rising sea levels will submerge low-lying coastal areas, such as Oceania islands Tuvalu have been flooded . Worldwide there are 3 /4 of the population live in less than 500 km from the coast where the land area is reduced greatly affect human living environment , and may even lead to war . River seawall establishment , can reduce the impact of rising sea levels and protect low-lying areas . ( Note that the widely circulated " floating on the oceans and melting of glaciers and sea level rise " argument is wrong. According to Archimedes' principle , in fact , melting glaciers floating on the ocean sea levels will remain after unchanged only when the land into the ocean after melting glaciers will change sea level )
As ocean temperatures , water evaporates faster, a lot of water vapor is transported into the atmosphere will lead to a sudden increase in rainfall in some areas within a short time , so that heavy rain will cause flooding, landslides, mudslides and other more frequent occurrence in the city is located along the river and the river downstream of the vast region therefore subject to flooding , flood area because of short-term and rapid expansion of heavy precipitation , soil erosion problems are more severe than in the past .
As atmospheric temperature, resulting in proliferation of tropical infectious diseases to high latitudes , there are already signs of the spread of tropical diseases . In the past, at low temperatures, the virus is difficult to survive winter temperatures rise as there may be activities throughout the year , the most recent monitoring found that in the past has been the control of diseases such as tuberculosis , which are likely to break out again .
As atmospheric temperature increases, so evaporation rise in the previous drought areas face a more severe test without proper farming methods is likely to allow previously vegetated semi-arid areas unprotected become semi-desert region , which resulted in the accelerated desertification land areas , deserts expand danger ( in fact desertification problem has plagued East and Central Asian countries , in the Sahara border region is worrying situation ) .
As temperature increases, if the top of the food chain in the upper layer and the corresponding changes in biological if it will not make a serious crisis to breeding populations and development of the entire biological diversity will be threatened, many species will accelerate the pace of extinction .
As polar ice collapses , Scandinavia, South America, near-polar where the temperature will drop rapidly ( due to ice melt has melted latent heat , a lot of ice also melts will absorb a lot of energy for melting , and therefore the near-polar where the temperature will drop rapidly ) , will seriously affect the local ecosystem , causing irreversible changes.
Australia epidemiologist Antonio McMichael (Anthony McMichael) in the American Society for Microbiology 's meeting warned that global warming makes a variety of epidemic outbreak of epidemic mode change to increase opportunities .
Due to extreme weather causes crop failure , reduced food supplies in some areas causing serious economic losses, and even lead to famine , such as droughts cause desertification in Africa, to expand the scope of agricultural land decreased productivity .
Other views on global warming
(※ The views are independent )
In fact , the Earth 4.6 billion years ago, continue to experience the cold of global warming , sea level rise and fall, when carbon dioxide levels are high and sometimes low , and some times even much higher than the current level , not fixed . Since the air temperature, sea level , carbon dioxide levels are constantly changing, and the most recent decades temperature , sea level and changes in the level of carbon dioxide in the natural range of variation completely . Now " prevent global warming " in trying to make the Earth's temperature behavior to maintain a certain violation of the laws of nature .
" Average temperature " , the temperature should be what age is ambiguous as standard , not to mention billions of years of Earth's history, nearly two thousand years of human history , there have been Medieval Warm Period and Little Ice Age both average temperature extreme opposite situation , in the absence of criteria for determining what temperature is considered unreasonable to talk about preventing global warming .
Sea level in the tens of thousands of years has been on the rise , with little human activity . Initially, Asia and the Americas , Japan, Taiwan and the Asian continent , the United Kingdom and continental Europe are linked together , and later was only separated from sea level rise , so will sea level rise is mainly attributable to human inappropriate, is the lack of scientific knowledge embodied .
" Carbon " and " prevent global warming " and other slogans actually become political show, signed the " Kyoto Protocol" countries do not actively saving, and even increased . ( See the relevant chapter Kyoto Protocol ) make people suspect it is the politicians in order to scare up votes means.
Some countries in order to " prevent global warming " as the name of levying various taxes , increasing national burden , so that the original line of the population living in poverty is more poverty. These countries do not focus on improving technology to reduce carbon emissions but seeking only to collect taxes , attracting people's criticism. So that people suspected " global warming " is a multi- government to collect taxes from the people who deliberately exaggerated.
Business benefits: Many businesses put " low carbon " as a propaganda tool , and low-carbon products are often more expensive than other products , if forced to give up ordinary products and switched to a low-carbon products will increase the burden on the poor is immoral .
Some claimed to be able to reduce greenhouse gas emissions approach , in fact it will increase greenhouse gas emissions , such as biofuels ; while the effect of planting is suspected because of this process and the plant itself greenhouse gas emissions may be higher than it could be effective in reducing more greenhouse gas emissions .
According to chemical principles , " lights a candle " actually emit more carbon . Therefore, the "Earth Hour " lights a candle in fact, many people with their carbon reduction claims contrary , show more ingredients .
So that those who died in the cold wave to reduce global warming , said to refer to the heat wave killed more people than cold . Some people think that global warming makes the high latitudes in summer hotter , colder winter climate extremes often occur . But in fact , the occurrence of cold wave is just proof of global warming the earth did not happen . Moreover, warming , cooling blame global warming is clearly an unscientific irrational , contrary to the scientific principle of falsifiability .
2013 Arctic summer cover area than in 2012 increased by 60 % over one million square miles. Scientists warned that the world is experiencing rapid decline in temperature , may face global cooling . Temperatures will continue to drop rapidly after the middle of this century . According to the computer before this catastrophic climate warming is predicted dangerously misleading
全球暖化
全球暖化[編輯]
維基百科，自由的百科全書
在20世紀時，全球平均接近地面的大氣層溫度上升了攝氏0.74度。[1] 普遍來說，科學界發現過去50年可觀察的氣候改變的速度是過去100年的雙倍，
因此推論該時期的氣候改變是由人類活動所推動。[1]全球暖化（global warming） 指的是在一段時間中，
地球的大氣和海洋因溫室效應而造成溫度上升的氣候變化現象，為公地悲劇之一，
而其所造成的效應稱之為全球暖化效應。
二氧化碳和其他溫室氣體的含量不斷增加。[2] 正是全球暖化的人為因素中主要部分。據資料顯示[3] ，大氣中一氧化二氮（N20)的含量比18世紀中葉（西元1750年）工業革命開始從275ppbv增加到310ppbv，二氧化碳（CO2）的含量從280ppmv增加到360ppmv，甲烷（CH4）從700ppbv增加到1720ppbv，這些增長趨勢主要緣於人類的活動。燃燒化石燃料、清理林木和耕作等等都增強了溫室效應。自從1950年，太陽輻射的變化與火山活動所產生的變暖效果比人類所排放的溫室氣體的還要低。[4][5] 這些結論得到30多個來自八大工業國家的研究團體所確認。[6][7]
目前全球平均溫度的變化，二氧化碳濃度的變化與氣溫上升，實際上並沒有直接的關係，從工業革命開始，二氧化碳的含量急劇增加，雖然植物的光合作用吸收了很大一部分二氧化碳，海洋也溶解一部分二氧化碳並固定成碳酸鈣，但空氣中二氧化碳的含量還是逐步增加。根據美國維吉尼亞大學和英國東安格里亞大學聯合研究的結果，在進入20世紀後半葉，全球溫度上升的趨勢非常明顯，溫度變化情況見下圖。
全球性的溫度增量帶來包括海平面上升和降雨量及降雪量在數額上和樣式上的變化。這些變動也許促使極端氣候事件更強更頻繁，譬如洪水、旱災、熱浪、颶風和龍捲風。除此之外，還有其它後果，包括更高或更低的農產量、冰河撤退、夏天時河流流量減少、物種消失及疾病肆虐。預計全球暖化所因致事件的數量和強度；但是很難把這些特殊事件連接到全球暖化。因為二氧化碳在大氣中有50年到200年的壽命[10]，很多研究集中在2100年或之前的時間。但是無論氣候變化的成因或結果為何，許多人是非常關心的；而且對於應付預言後果的政策應該如何實施，引起了全球廣泛的政治爭論、公開辯論及各種學術研究。這些政策討論重點是應該減少還是扭轉未來的暖化及怎麼應付預計的後果。
目錄
[隱藏]命名法則[編輯]
原則上，「全球暖化」一詞對成因持中立觀點，但是根據大眾的用法，「全球暖化」意味著人類對環境的影響。[11][12] 其他組織則使用「人為的氣候改變」（anthropogenic climate change）代表人為因素導致的改變。
歷史上的全球暖化[編輯]
根據儀器記錄，相對於1860年至1900年期間，全球陸地與海洋溫度上升了攝氏0.75度。自1979年，陸地溫度上升速度比海洋溫度快一倍（陸地溫度上升了攝氏0.25度，而海洋溫度上升了攝氏0.13度）。根據衛星溫度探測，對流層的溫度每十年上升攝氏0.12度至0.22度。在1850年前的一兩千年，雖然曾經出現中世紀溫暖時期與小冰河時期，但是大眾相信全球溫度是相對穩定的。
根據美國國家航空暨太空總署戈達德太空研究所的研究報告估計，自1800年代有測量儀器廣泛地應用開始，2005年是地球有溫度記錄以來第二溫暖的年份，比1998年的年平均地表溫度記錄低了0.06攝氏度。世界氣象組織和英國氣候研究單位也有類似的估計，曾經預計2005年是僅次於1998年第二溫暖的年份。[13][14]
在人類近代歷史才有一些溫度記錄。這些記錄都來自不同的地方，精確度和可靠性都不盡相同。在1860年才有類似全球溫度儀器記錄，相信當年的記錄很少受到城市熱島效應的影響。從最近的千禧年內的多方記錄所展示的長遠展望，在過去1000年的溫度記錄中可以看到有關的討論及其中的差異。最近50年的氣候轉變的過程是十分清晰，全賴詳細的溫度記錄。到了1979年，人類更開始利用衛星溫度測量來量度對流層的溫度。
在2000年後，各地的高溫記錄經常被打破。譬如：2003年8月11日，瑞士格羅諾鎮錄得攝氏41.5度，破139年來的記錄。同年，8月10日，英國倫敦的溫度達到攝氏38.1度，破了1990年的記錄。同期，巴黎南部晚上測得最低溫度為攝氏25.5度，破了1873年以來的記錄。8月7日夜間，德國也打破了百年最高氣溫記錄。在2003年夏天，台北、上海、杭州、武漢、福州都破了當地高溫記錄[15][16]，而中國浙江省更快速地屢破高溫記錄，67個氣象站中40個都刷新記錄。[17]2004年7月，廣州的罕見高溫打破了53年來的記錄。[18]2005年7月，美國有兩百個城市都創下歷史性高溫記錄。[19] 2006年8月16日，中國重慶最高氣溫高達43度。[20] 台灣宜蘭在2006年7月8日溫度高達38.8度，破了1997年的記錄。[21] 2007年8月16日，日本埼玉縣熊谷市溫度高達40.9度，破了1933年日本山形市的記錄。[22]
成因[編輯]
氣候系統的改變來自自然或內部運作及對外來力量的改變作出的反應。這些外來力量包括了人為與非人為因素，譬如太陽活動、火山活動及溫室氣體。多名氣候學家同意地球近年來已經變暖。近代氣候轉變的成因仍然是活躍的研究範疇，但是科學界的共識指出溫室氣體是全球暖化的主因。可是，科學界外仍然對此結論有爭議。
在地球大氣層排放二氧化碳及甲烷，而其他情況不變下，會促使地面升溫，溫室氣體產生天然的溫室效應。如果沒有它，地球溫度會比現在低攝氏30度，使地球不適合人類居住。因此，在支持與反對這套變暖理論之間爭辯是不正確的，反而應該側重於大氣層中二氧化碳及甲烷含量的增加所產生的最終效果，什麼時候應該促進或什麼時候才同意使之緩和。
舉一個重要的回饋過程的例子，就是冰反照率回饋。大氣層中增加二氧化碳暖化了地球表面，導致兩極冰塊溶解。陸地與開放水域便佔據更多的地方。兩者比冰的反射還要少，所以吸收了更多太陽輻射。這樣使變暖加劇，到頭來促使更多冰塊溶化，循環不斷持續。
大氣層中的溫室氣體[編輯]
大氣層中二氧化碳及甲烷的濃度自1750年比前工業化水平（280百萬分率）分別上升了31%與149%。而現在的水平已經高於380百萬分率。從冰芯中提取可靠的數據指出，與過去65萬年的作比較，這是個明顯的飆升。從一些非直接的地質學證據，有理由相信過去4000萬年的二氧化碳含量比較高。在過去的20年中，大約四分之三的人為的二氧化碳排放都是燃燒化石燃料。其他的人為排放都是土地使用方面，特別是砍伐森林。[23]
1958年在夏威夷大島海拔約3400公尺的毛納洛峰上對二氧化碳混合比率展開了最漫長的連續的儀器測量。從此以後，人們發現每年的測量結果不斷攀升，如基林曲線（Keeling Curve）顯示，數值由當初的315百萬分率上升至2006年超過了380百萬分率，升幅大約是21%。[24][25] 結果顯示二氧化碳含量在每個月出現輕微季節性變動而整體上全年是不斷上升。
甲烷是天然氣的主要組成部分，大部分由生物生產和從天然氣管道和其它基礎設施洩漏出來。一些甲烷的生物來源是自然的，譬如白蟻。可是其他來源則是由人類農業活動增加而帶動的，例如稻米的耕種。[26] 最近的證據顯示，森林也許是甲烷的來源[27][28]。如果屬實，這會是對天然溫室效應的額外貢獻，而不是人為溫室效應的。[29]
雖然實際的趨勢軌線視乎不確定的經濟、社會、科技及自然發展，預期未來的二氧化碳水平將因為使用化石燃料而持續攀升。政府間氣候變化委員會的《排放情況的特殊報告》羅列出很多不同的二氧化碳情況，在2100年可以達致由541至970百萬分率的水平。[30] 如果煤與焦油被廣泛地採用，現時的化石燃料儲備是有能力實現這個水平並且在2100年後繼續排放。
全球的主要人為排放的溫室氣體是來自燃燒燃料。餘下的大部分來自「短暫的燃料」（生產與運送中耗用的燃料）、工業及農業體增多。生產中的排放。在1990年，他們的比重分別是5.8%、5.2%和3.3%。當前的數據都可以作比較。[31] 大約17%來自發電時所耗用的燃料。很少來自大自然與人為生物來源，大約只有6.3%來自農業所產生的甲烷和氧化亞氮。
正回授效果會導致更多溫室氣體的來源。譬如從西伯利亞永久凍土中的泥煤田釋放的甲烷可能多達7百億噸。 [32] 注意人類排放的污染物如硫酸鹽氣溶膠有冷卻的作用。雖然被干擾的自然循環可能導致二十世紀中期的溫度記錄中所見的高原，但那些人類排放的污染物在某個程度上也引致同樣的溫度記錄[33]
大氣中二氧化碳濃度的趨勢性研究[編輯]
通過討論已有的60年來（1948～2008年）大氣中二氧化碳（CO2）濃度數據(From reports of Pieter Tans. etal)的分布狀態，採用趨勢分析方法，給出了具體趨勢方程形式。與冰芯分析或觀測數據對比結果表明，趨勢方程曲線與已有數據基本符合，隨後給出了2010～2016年間大氣中CO2濃度預測值（389～402ppmv），並進而對CO2濃度與氣候變化的關係予以了初步探討[34]。
- 如果沒有溫室效應，人不能生存。只是二氧化碳令溫室氣體增多。
另外一些理論[編輯]
人類曾企圖測量關於「在過去50年觀察得到的大部分暖化都是由人類活動所致的」的科學公眾輿論程度。 [35] 在科學雜誌中，加州聖迭戈大學的歷史學教授納奧秘·奧勒斯克斯從科學資訊機構中的928份科學文獻的摘要中尋找全球氣候改變（global climate change）。他得出結論，當中75%明示或暗示接受了這個公眾輿論的觀點。[36][37] 可是，奧勒斯克斯教授並沒有表示多少摘要指出人類導致的暖化效果。
除了這個公眾輿論外，還有其他的假說嘗試解釋全部或部分的全球溫度升高的原因。某些假說如下：
- 全球溫度升高仍然屬於自然溫度變化的範圍之內。
- 全球溫度升高是小冰河時期的來臨。
- 全球溫度升高的原因是太陽輻射的變化及雲層覆蓋的調節效果。[38]
- 全球溫度升高正反映了城市熱島效應。因為很多讀數都在人口稠密或正在擴張的地區。[39]
太陽變化理論[編輯]
政府間氣候變化專門委員會的第三份評估報告所闡述的模型研究發現最近40至50年的氣候改變並不需要太陽發光度的變動。[40] 這些研究發現火山及太陽活動只能影響1950年前的溫度改變的一半，但這種自然力量最近已經被抵消。[41] 特別是，自1750年的溫室氣體所推動的氣候改變比同期增加的太陽活動所推動的高出八倍。[42]
有些研究（Lean等人，2002年；Wang等人，2005年）認為前工業時期的太陽發光度比第三份評估報告中所提及的復原紀錄（例如:Hoyt和Schatten，1993年；Lean，2000年）還少三四倍。其他研究人員[43] 相信太陽發光度對全球暖化的影響被低估了。他們估計太陽活動促使近來溫室效應的16%或36%。其它人[44] 則建議雲層和其他過程的回饋加劇了太陽活動的變動所帶來的影響。如果是真的，太陽活動的變動真的被低估了。從普遍的科學理解來說，太陽發光度變動對歷史上的氣候改變貢獻是十分小[45]。
現在的太陽活動水平是歷史性高。科學家薩米·索蘭基（Sami Solanki）博士等人認為過去60年至70年的太陽活動是八千年來的高峰期。[46] Muscheler等人則認為過去幾千年都曾經出現類似的高峰期。[47] Solanki博士根據他們的分析斷定了太陽活動在未來的50年會降低的機會率大約是92%。再者，美國杜克大學的研究者在2005年發現過去二十年的改變中的10%至30%可能來自增加的太陽輸出。[48] 回顧了現有的文獻，Foukal等人斷定自從1970年代中期太陽輸出的變化很難加劇全球暖化並且沒有證據顯示太陽發光度在這個時期有所增加。[49][50]
植被、森林資源與全球暖化的關係[編輯]
全球森林資源是有效防止全球暖化的工具。樹木通過光合作用吸收空氣中的二氧化碳，生成氧氣和糖類。當人類將森林破壞後有一部分會被用作燃料使用用於供暖或是燒製成碳木。在使用的過程中燃燒會產生二氧化碳，增加二氧化碳在大氣中的含量，進一步加重溫室效應，加速全球氣溫變暖。因此，一方面減少吸收二氧化碳這種主要溫室氣體的數量，另一方面又會增加二氧化碳的排放。所以破壞或是不合理使用森林資源資源是對環境的嚴重破壞，是全球氣溫上升的一大誘因。[51][52] 大面積的草原與植被同樣具有吸收二氧化碳與涵養地下水的功能，草原與植被嚴重破壞的區域同時會造成嚴重沙塵暴，加速草原與植被的沙漠化。
道德、社會及政治爭議[編輯]
過去幾年以來，大眾對地球暖化的重視程度明顯提升。[53] 人們對地球暖化原因的各項科學解釋高度關注，同時引起了政治與經濟上的辯論。雖然貧窮地區，特別是非洲的排放量很微小，但卻面對著全球暖化所帶來的極大風險。[54] 同時，美國不滿發展中國家能夠免除京都協議書的約束，並且以這個為拒絕簽署協議書的理由。[55] 在西方社會中，相比美國，歐洲有很多人接納了人類對氣候的影響及努力對抗變暖這些說法。[56][57]
化石燃料組織及公司譬如由菲利普·庫尼（Philip Cooney）及某些智庫－競爭企業協會和卡托研究所所代表的美國石油學會及艾克森美孚利用一些運動來淡化全球暖化的風險。[58][59][60][61] 環保團體及公眾人物則舉行運動來強調當中的風險。最近，一些化石燃料公司已經減少了淡化運動[62]，甚至呼籲制定避免全球暖化的政策。[63]
這個議題促發了關於限制工業的溫室氣體排放對經濟活動的影響的辯論。在美國，對科學證據及報告作政治操控也成了重要的議題。[64][65] 其他國家則更會討論為了減排而採取另外一些更潔淨能源時所需要的成本。[66]
其他爭論焦點則在於一些新興工業國家如印度及中國在控制排放的力度應該有多大。2007年，中國的二氧化碳排放量已經超越美國，中國辯稱因為中國人均排放量是美國的三分之一（2010年），所以在減排上沒有很大責任。美國辯稱如果他們必要承擔減排成本，中國也要。[67][68]印度也快將成為工業排放的大國之一，將會與中國一樣面對同樣的問題。[69]
造成的影響[編輯]
- 由於海洋溫度升高，海水體積膨脹，南極和格陵蘭的大陸冰川也會加速融化，導致海平面上升，會淹沒沿海低海拔地區，例如大洋洲島國圖瓦魯已被水淹沒。全世界有3/4的人口居住在離海岸線不足500公里的地方，陸地面積縮小會極大地影響人類居住環境，甚至可能導致戰爭。河、海堤的建立，可降低海平面上升的影響，保護地勢低的地區。（要注意，廣為流傳的「海洋上漂浮的冰川的融化會導致海平面上升」的說法是錯誤的。根據阿基米德原理，實際上，海洋上漂浮的冰川融化後海平面仍會保持不變。只有當陸地的冰川融化後流入海洋才會改變海平面的高度）
- 由於海洋溫度升高，水蒸發加快，大量水氣被輸送進入大氣，會導致局部地區短時間內降雨量突然升高，這樣暴雨天氣就會導致水災、山體滑坡、泥石流等更加頻繁的發生，位於河流沿岸的城市和位於河流下游的廣大地區因此受到洪水的威脅，水災面積因為短時的強降水而迅速擴大，水土流失問題也比過去更加嚴峻。
- 由於大氣溫度升高，導致熱帶傳染病向高緯擴散，目前已有熱帶傳染病擴散的跡象。而過去在低溫下難以存活的病毒隨著冬季溫度上升，有全年活動的可能，最近一段時間的監控發現，過去已經得到控制的疾病如結核病等有再度爆發的可能。
- 由於大氣溫度升高，令蒸發量上升，在以往乾旱少雨的地區面臨更加嚴峻的考驗，而不正確的耕作方法很有可能讓以前植物覆蓋的半乾旱地區失去保護成為半沙漠化地區，從而導致內陸地區沙漠化加速，沙漠有擴大的危險（實際上沙漠化問題已經困擾著東亞和中亞國家，在撒哈拉邊界地區更是情況堪憂）。
- 由於溫度升高，如果食物鏈中的上層和頂層生物如果不作出相應變動就會嚴重危機到種群的繁殖和發展，整個生物多樣性會受到威脅，許多物種會加速滅絕的步伐。
- 由於兩極冰山崩塌，北歐、南美近極地的地方溫度會迅速下降（因冰溶化有溶化比潛熱，大量冰同時溶化會吸取大量能量以作溶化之用，所以近極地的地方溫度會迅速下降），會嚴重影響當地生態系統，造成不可逆的變化。
- 澳洲流行病學家安東尼奧·麥克邁克爾（Anthony McMichael）於美國微生物學會的會議上提出警告，表示全球暖化使得多種流行病的流行模式發生改變增加爆發機會[70]。
- 由於極端氣候會使農作物失收，減少糧食供應，在一些地區造成嚴重的經濟損失，甚至引致饑荒，例如乾旱會使非洲的荒漠化範圍擴大，農地生產力下降。
對全球暖化的其他看法[編輯]
（※各看法互相獨立）
- 實際上，地球46億年來，不斷經歷溫暖化與寒冷化，海平面也有升有降，二氧化碳水平也時高時低，有的時代甚至遠高於現在的水平，並不是固定不變的。既然氣溫、海平面、二氧化碳水平都是不斷變化的，而最近幾十年氣溫、海平面和二氧化碳水平的變化完全在自然變化範圍內。現在「防止全球暖化」的行為試圖讓地球的溫度保持一定違反了自然規律。
- 「平均氣溫」應當以什麼時代的氣溫作為標準也是含糊不清的，且不說數十億年的地球史，近兩千年的人類歷史中，就出現了中世紀溫暖時期和小冰期這兩種平均氣溫極端對立的情況，在沒有確定什麼氣溫才算標準時去談防止全球暖化並不合理。
- 海平面在數萬年來一直是在上升的，與人類活動關係不大。最初，亞洲與美洲、日本台灣與亞洲大陸、英國與歐洲大陸都是連在一起的，後來海平面上升才被分開，因此，將海平面上升的主要原因歸咎於人類是不合適的，是缺乏科學常識的體現。
- 「低碳」和「防止全球暖化」等口號實際上成了政治作秀，簽訂了《京都議定書》的國家並不積極減排，甚至還有所增加。（見京都議定書相關章節）令人們懷疑這是政客們為了騙取選票的手段。
- 一些國家以「防止全球暖化」為名義，開徵各種稅收，加重國民負擔，使原本處於貧困線上的人口更加貧困。這些國家並不著眼於改進技術減少碳排放而是只顧著收稅，引來人們的批評。使人們懷疑「全球暖化」是政府為了從人民身上多收稅而故意誇大。
- 商業利益：許多商家把「低碳」作為一種宣傳手段，而低碳產品往往比其他產品更貴，如果強制放棄普通產品而改用低碳產品會加重貧困人口的生活負擔，是很不道德的。
- 一些號稱能減少溫室氣體排放的作法，事實上反而會增加溫室氣體排放，例如生質燃料；而植樹的效應也是被懷疑的，因為此過程及植物本身所排放的溫室氣體可能比其能有效減少的溫室氣體更多。
- 根據化學原理，「關燈點蠟燭」實際上排放更多的碳元素。因此，「地球一小時」中許多人關燈點蠟燭實際上與他們減碳的主張相違背，作秀的成分更多。
- 全球暖化令死於寒潮者減少，有說指死於寒潮的人比熱浪多。[71] 有人認為，全球暖化使得高緯度地區夏天更熱，冬天更冷的極端氣候常發生。[72] 但事實上，發生寒潮恰恰證明地球沒有發生全球暖化。而且，變暖、變冷都歸咎於全球暖化顯然是一種不科學的強詞奪理，違背了科學的可證偽性原則。
- 2013年北極夏季蓋面積比2012年增加了60%，超過100萬平方英里。科學家警告，世界正在經歷氣溫急速下降，可能面臨全球變冷。氣溫急速下降將持續到本世紀中葉以後。前此根據計算機預測災難性的氣候變暖是危險的誤導
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