Global warming
Basic introduction
Nearly 100 years, the average global
temperature has experienced: cold and warm to cold, warm, four on the whole the
temperature to rise. After entering the eighty s,
global temperature rise significantly.
The global atmosphere and the
surface of this system is like a huge "glass greenhouse", make the
earth's surface has always maintained a certain temperature, the suitable for
humans and other biological survival environment. In this system, can not only
let the sun radiation through the atmosphere and reach the ground, and also can
prevent the ground radiation loss, we put the atmosphere on the surface of this
protective effect is called the atmospheric greenhouse effect (green house
effect). Known as the greenhouse gases "greenhouse gases", they can
make the sun shortwave radiation through freedom, at the same time can absorb
long-wave radiation from the earth's surface. These gases have a carbon
dioxide, methane and chlorofluorocarbons, ozone, nitrogen oxide and water
vapor, etc., is one of the main carbon dioxide. Over the past century global
climate is gradually warming, at the same time, the content of greenhouse gases
in the atmosphere are also increased dramatically. Many scientists agree that
greenhouse gas emissions of the greenhouse effect caused by the fuel is the
basic cause of global warming.
Human burning coal, oil, natural
gas, and trees, produce large amounts of carbon dioxide and methane into the
atmosphere after the heating, the carbon cycle imbalances, changed the form of
energy conversion, the earth's biosphere. Since the industrial revolution,
increased by 25% content of carbon dioxide in the atmosphere, more scientists
may survey out all of the past 160000 years of history, and shows no sign of
slowing down.
Increase in carbon dioxide emissions
in the atmosphere is the cause for the earth warming. The international energy
agency, according to a survey of the United States, China, Russia and Japan
accounted for almost half of the total global carbon dioxide emissions.
Research shows that carbon dioxide emissions are the highest in the world in
the United States, in about 20 tons of co2 emissions per capita, emissions of
carbon dioxide accounting for 23.7% of the global total. China's annual per
capita carbon emissions is about 2.51 tons, accounts for about 13.9% of the
global total.
Background introduction
Global warming is refers to the global
temperature rise. Nearly 100 years, the average global temperature has
experienced twice cold - warm - cold - warm fluctuations, the overall look for
rising trend. After entering the eighty s, global temperature rise
significantly.
The average global temperature from
1981 to 1990 increased by 0.48 ℃ more than 100 years ago. Cause the main cause of global warming is human
in almost a century extensive use of fossil fuels such as coal, oil, etc.),
emissions from a large amount of CO2 and other greenhouse gases. Because these
greenhouse gases to the visible light radiation from the sun (3.8-7.6 nm, shorter
wavelength) with high penetrability, and its reflection on the earth long wave
radiation (such as infrared) are highly absorbent, which is often said that the
"greenhouse effect", leading to global warming.
The
specific reason for this is that people burn fossil minerals to produce energy
or deforestation and burning the carbon dioxide produced when it entered the
earth's atmosphere. Intergovernmental panel on climate change, according to the
climate models predict by the year 2100, global temperature estimation would
rise by about 1.4 to 5.8 ℃ (2.5 to 10.4 degrees Fahrenheit). According to the
forecast, global temperatures will appear in the past 10000 years has never had
the huge change, and thus potentially significant impact on the global environment.
To
prevent the global warming trend, in 1992 the United Nations specifically
developed to the UN framework convention on climate change, the convention in
the same year in the Brazilian city of Rio DE janeiro is signed into law. On
the basis of the convention, developed countries agreed to by 2000 they
released into the atmosphere of carbon dioxide and other emissions of
"greenhouse gases", down to 1990 levels. In addition, the total
carbon dioxide emissions a year accounted for 60% of the world's carbon dioxide
emissions countries also agreed to the related technology and information
transfer to developing countries. Developed countries to the developing
countries of the technology and the information can help the latter actively
respond to challenges from climate change. As of May 2004, 189 nations have
formally approved the treaty.
The earth
is heating up, in the last century the world's average temperature rose about
0.6 degrees Celsius. In the northern hemisphere spring snow thawing period for
nine days earlier than 150 years ago, and the autumn frosts start time is late
10 days or so.
Is the
temperature record since the middle of the 19th century in the 1990 s the
warmest decade since, the hottest years on record, in turn, is: 1998, 2002,
2003, 2001 and 1997.
Cause analysis
Human factors
1. The population factor
The dramatic increase in population is one of
the main factors that contribute to global warming. At the same time, it also
seriously threatens the balance between natural ecological environment. So many
people, only their own emissions of carbon dioxide each year will be a
staggering Numbers, the result will be directly responsible for the content of
carbon dioxide in the atmosphere increases unceasingly, this form of carbon
dioxide "greenhouse effect" will directly affect the earth's surface
climate change.
2. Atmospheric environmental
pollution factors
Increasingly serious environmental pollution has
constituted a major global problem, is also one of the main factors that
contribute to global warming. Now, on global climate change research has
clearly pointed out that since the end of last century had started to rise the
temperature of the earth's surface.
3. The Marine ecological environment deterioration factors
The change of sea level is
continuously rising, according to experts predict the next century, sea level
could rise 50 cm. If you don't take on the measures, will directly cause the
destruction of freshwater resources and pollution. In addition, land activities
to produce large amounts of toxic chemical waste and solid waste constantly
into the sea; Major in sea water in the oil (leak) events and caused by human
activities such as coastal areas such as the destruction of the ecological
environment is the main factor that leads to the ecological environment
destruction.
4. Land erosion, salinization, desertification and other factors
Soil erosion and desertification is
the main reason of the inappropriate agricultural production. As is known to
all a good vegetation can keep the soil and water loss. But so far, human
activities such as for wood and deforestation, cultivated land used for
agricultural production and overgrazing reason, is still a serious damage to
vegetation. The world per minute on average 20 hectares of forest are
destroyed, 10 hectares of land desertification, 47000 tons of soil erosion.
Soil erosion decreased soil fertility and water retention, thus reducing the
biological productivity of the soil and its ability to maintain productivity;
And can cause a wide range of floods and dust storms, causing great economic
losses to the society, and the worsening ecological environment.
5. The forest resources in factors
Around the world, because of natural
or man-made factors causing forest area is greatly reduced.
6. Acid rain harm factors
The effects of acid rain to the
ecological environment has become more and more attention all over the world.
Acid rain can destroy forest, acidification lakes, endanger biological, etc. At
present, the acid rain in the world more concentrated in Europe and North
America, most of the acid rain occurred in developed countries, some developing
countries, acid rain, also in the occurrence and development rapidly.
7. Factors accelerate extinctions
Life on earth is a valuable human
resources, and biodiversity is the foundation of human survival and
development. But the biological species on the earth is at an unprecedented
rate.
8. Water pollution factors
According to the global environment
monitoring system for water quality monitoring project shows that about 10% of
the global monitoring of the pollution of the river, since this century, the
human water consumption is dramatically increased, at the same time, water
pollution, scale is continually expanding, this creates a contradiction between
supply and demand of fresh water. Therefore, the treatment of water pollution
is very urgent and important.
9. Toxic waste pollution factors
Growing toxic chemicals not only
pose a serious threat to human survival, but also to the ecological environment
of the earth's surface will lead to harm.
Natural factors
1. The volcanic activity
2. The earth periodic track changes
The earth periodic track by oval
into circular trajectory, distance closer to the sun. According to some
scientists study the earth's temperature has a moderate high low temperature
alternating, there is a certain regularity.
Continued warming
The China meteorological
administration, deputy director of the national climate center, said luo
according to many scientists predict that in the world in the next 50-100 human
will completely into a warming world. Due to the influence of human activity,
in the 21st century, the concentration of greenhouse gases and sulphate
aerosols increase quickly, make future 100, east Asia and China in the world of
temperature rising rapidly, the global average surface temperature to rise 1.4 ℃ to 5.8 ℃. By 2050, China will raise average
temperature 2.2 ℃.
"Frequent
rare heavy fog weather since winter is also a sign of warmer winters." Luo
said that the fog weather is due to "warm winter" cause strong cold
air is very weak. The reality of global warming is to ring alarm bells around
the world, climate warming has the serious influence to human survival and
sustainable development of society, it is not only a matter of science, and it
is a political, economic, energy and other aspects of the comprehensive
problem, the fact that global warming has risen to the height of national
security.
1. The ecological
First of all, global warming, rising
sea levels, precipitation distribution again, change the current pattern of the
world's climate; Second, global warming and destroyed the food chain, food
chain, have more serious natural consequences. Every year, for example, have a
kind of migratory birds, flying from Australia to summer in northeast China,
but due to global warming temperatures in northeast China, summer extended, the
birds left the northeast time corresponding warming, once again return to the
northeast of time also corresponding delay. As a result of this kind of
migratory birds eat a pest overrun, destroyed large tracts of forest. In
addition, the environment of extreme events increase, such as drought, flood,
etc.
2. The political
Limit emissions of carbon dioxide,
and restrictions on the consumption of energy, will the conditionality of the
impact on the world. Should be "reduction" in developing countries,
or in the developed countries "emission reduction" has become the
focus of the discussion questions. Increasing greenhouse gas emissions in the
developing world, 2013 years after the "reduction" of the problem is
bound to be concentrated in developing countries. Scientific questions about
stopping global warming will inevitably "north-south relations"
problem, so that the climate become an international political issue.
3. The climate
Global warming make the mainland
area, precipitation increase, especially in the high latitudes such as Africa,
rainfall in some regions. Some parts of extreme weather events (el nino,
drought, floods, thunderstorms, hail, storms, heat and dust storms, etc.) in
the frequency and intensity increase.
4. The ocean
As global temperatures rise, the
ocean evaporation of water vapor volume increased significantly, contributed to
the warming. The decrease of the overall heat capacity and Marine and curb
global warming. In addition, due to the ocean to the release of the excess
carbon dioxide in the atmosphere, thus the real culprit is the ocean
phytoplankton community.
5. The crops
The effects of global climate
warming on crops growth cut both ways. First, the global temperature changes
directly affect the global water cycle, in some parts of the drought or
flooding, crop production, and high temperature is unfavorable to the seeds.
Second, the precipitation increase especially in arid regions can promote crop
growth. With increased carbon dioxide levels of global warming will also
promote the crop photosynthesis, to increase production.
6. Human health
(1) as a direct result of global warming in some parts of
summer super high temperature, heart disease and various respiratory diseases
caused by, every year will take a lot of people's life, and with the biggest
risk of newborns and the elderly. (2) global warming lead to ozone
concentration increases, the ozone in the low altitude is very dangerous
contaminants, will destroy man lung tissue, trigger asthma or other lung
disease. (3) global warming will cause
some infectious diseases.
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