Global climate warming is a phenomenon related to nature. It is due to the continuous accumulation of greenhouse effect, which leads to the imbalance of energy absorbed and emitted by the earth atmosphere system. Energy is continuously accumulated in the earth atmosphere system, which leads to temperature rise and global climate warming.
Because people burn fossil fuels, such as oil,coalOr cutting down forests and burning them will produce a large amount ofcarbon dioxide, i.egreenhouse gasesThese greenhouse gases are highly permeable to visible light from solar radiation, and emitLong wave radiationIt is highly absorbent and can strongly absorb the infrared ray in the ground radiation, causing the earth temperature to rise, namelygreenhouse effect。Global warming will lead to redistribution of global precipitation, glaciers andfrozen soilAblationsea level riseAnd so on, not only endangering natureecosystemThe balance ofImpact on human health[7]It even threatens the survival of human beings.
On the other hand, due to the greenhouse gas emissions from land, the temperature of the mainland will rise, and the temperature difference between the mainland and the sea will become smaller, thus slowing down the air flow,smogIt cannot be blown away in a short time, resulting in more smog in many cities and affecting human health.Such measures as vehicle restrictions and production suspension have only short-term and local effects, and cannot fundamentally change climate warming and haze pollution.[61-62]
People burnFossilFuel andpetroleumSuch chemicals and service industries have damaged the ecological environment of industrial and agricultural rice fields and caused global warming.
The global average temperature from 1981 to 1990 increased by 0.48 ℃ compared with 100 years ago.The main reason for global warming is that human beings have used a lot of fossil fuels (such as coal, oil, etc.) in the past century and emitted a large amount of COtwoEtcgreenhouse gases。These greenhouse gases cause global warming.In the 20th century, the world's average temperature climbed by about 0.6 ℃.The spring thaw period of ice and snow in the Northern Hemisphere is 9 days earlier than 150 years ago, while the autumn frost starts about 10 days later.The 1990s was the warmest decade since the beginning of temperature recording in the mid-19th century. The hottest years on record were 1998, 2002, 2003, 2001 and 1997.
Global average temperature anomaly from 1850 to 2019
In 2019, the global climate system is warming faster, the phenological period is ahead of schedule, glaciers are melting, sea level rise... many historical records have been broken, and the climate extremes are increasing.In 2019, the global average temperature was about 1.1 ℃ higher than the pre industrial level, which was the second warmest year since there were complete meteorological observation records.The past five years (2015-2019) are the warmest since the complete meteorological observation records.Since the 1980s, each successive decade has been warmer than the previous decade.[1]
UN measures after warming
In order to stop the trend of global warming, the United Nations specially formulated《United Nations Framework Convention on Climate Change》, which was signed in Brazil in the same yearRio de JaneiroSignature takes effect.According to theconvention，developed countryAgreed to release them into the atmosphere by 2000carbon dioxideAnd others“greenhouse gases”The emissions of.In addition, these countries whose annual total carbon dioxide emissions account for 60% of the global total carbon dioxide emissions also agreed to transfer relevant technology and information todeveloping country。The technology and information transferred from developed countries to developing countries will help the latter to actively respond to the challenges posed by climate change.At present, 197 countries have officially ratified the above conventions.[2]
Reduce heat emission with a limited lifestyle: industry serves life, and the industry will naturally decrease due to limited supplies.The reduction of heat emission should be put on everyone's daily life habits. With a fixed lifestyle and living habits, we should develop fixed articles for daily use, use fixed articles for daily use, limit the abuse of articles for daily use, use limited articles for daily use, achieve limited production and processing, so as to curb industrial flooding and reduce heat emission.
Hazards after warming
The harms of warming involve all aspects of human existence, from natural disasters to the rupture of the biological chain.
Historical temperature
There are some temperature records in modern human history.The accuracy and reliability of these records vary from source to source.In one or two thousand years before 1850Medieval Climatic Anomaly AndLittle Ice Age However, the public has always believed that the global temperature is relatively stable.It was only in 1860 that there were instrument records similar to global temperature. The records of that year seldom considered citiesheat island effectImpact.However, according to the instrument records, the average temperature of the global land and sea increased by 0.75 ℃ between 1860 and 1900;Since 1979, the land temperature has increased by about twice as much as the ocean temperature (the land temperature has increased by 0.25 ℃, while the ocean temperature has increased by 0.13 ℃).In the same year, humans began to use satellite temperature measurements to measure the temperature of the troposphere, and found that the temperature of the troposphere rose 0.12 ℃ to 0.22 ℃ every decade.After 2000, many organizations studied the global temperature in the past 1000 years. After comparing and discussing these research results, it was found that the process of climate change since 1979 was very clear.In addition, other research reports show that since the beginning of the 20th century, the average temperature of the earth's surface has increased by about 1.1f (0.6 ℃);In the past 40 years, the average temperature has risen by about 0.5f (0.2-0.3 ℃);In the 20th century, the degree of global warming is more than any time in the past 400-600 years.
NASAGoddard Space Research InstituteAccording to the research report of, since the 19th century when instruments were widely used to measure and record temperature, 2005 was the warmest year, higher than the temperature recorded in 1998.world meteorological organizationSimilar estimates have been made by the UK Climate Research Unit. On the contrary, their measurements show that 2005 is the second warmest year after 1998.
After 2000, the high temperature records in various places were often broken.For example, on August 11, 2003, the temperature of 41.5 ℃ was recorded in Grono, Switzerland, breaking the 139 year record.In the same year, on August 10, the temperature in London, England, reached 38.1 ℃, breaking the 1990 record.During the same period, the lowest temperature measured at night in southern Paris was 25.5 ℃, breaking the record since 1873.On the night of August 7, Germany also broke the record for the highest temperature in a century.In the summer of 2003, Taipei, Shanghai, Hangzhou, Wuhan and Fuzhou all broke the local high temperature records, while Zhejiang Province of China broke the high temperature records more quickly, with 40 of the 67 weather stations breaking new records.In July 2004, the rare high temperature in Guangzhou broke the 53 year record.In July 2005, 200 cities in the United States set a historical high temperature record.On August 16, 2006, the highest temperature in Chongqing reached 43 ℃.The temperature in Yilan, Taiwan, reached 38.8 ℃ on July 8, 2006, breaking the record set in 1997.November 11, 2006 was the hottest day in Hong Kong in November, with the highest temperature of 29.2 ℃, higher than the average maximum temperature of 26.1 ℃ from 1961 to 1990.
Research forecast
According to the Russian Independent on July 31, 2013《Proceedings of the National Academy of Sciences》(PNAS) published an article saying that with the rise of sea level, about 1400 cities in the United States may be submerged by 2100.It is reported that this conclusion was obtained by Benjamin Strauss of the Climate Central Independent Research Center.According to his research report, by 2100, global warming will lead to a rise of 127 cm in sea level. At that time, about 1400 cities in the United States will face the threat of flooding.
In this research report, Strauss paid special attention to Florida and Louisiana in the United States.He believes that 2.7 million people in 150 cities in Florida and 1.2 million people in 114 cities in Louisiana will be under great threat.In addition, New Jersey, California and North Carolina are also threatened by flooding.
According to the research report in New Scientist magazine, the "aerosol method" can reduce the sunlight reaching the ground by one fifth.However, this way will also reduce the blueness of the sky, from the familiar blue to white.Ben Kravitz of the Carnegie Institute of Science in California, USA, said that mankind can solve the problems faced byenvironmental problems。However, this practice can also have side effects.He pointed out that the particles sprayed into the air have a diameter of 0.1 to 0.9 microns, which is responsible for reflecting sunlight back into space.However, because of these particles in space, the color of the sky will also change from blue to white.
American scientists found that ancient agricultural activities had prevented the world from entering a new glacial period.This shows that global warming caused by human activities may last for thousands of years.The researchers said that prehistoric farmers who cut down trees and reclaimed the first piece of land made methane and CO in the atmospheretwoThe content of greenhouse gases has changed greatly, and the global temperature has gradually risen.
University of VirginiaProfessor Radiman said: "If it were not for the greenhouse gases brought by early agriculture, the earth temperature would probably still be the temperature of the ice age." Radiman admitted that the research results are very controversial.
National Center for Atmospheric ResearchIt was said on the 17th that, through two new studies, scientists predicted that even if the world's greenhouse gas emissions stabilized at the level of 2000, the trend of global warming and sea level rise in this century would be irreversible.
Scientists from the National Center for Atmospheric Research published two papers in Science on the 18th, predicting the trend of global climate change from different perspectives.Their achievements will be evaluated by the Intergovernmental Panel on Climate Change under the United Nations and included in the next global climate change report released in 2007.
In the first paper, Wei Gray of the National Center for Atmospheric Research proposed a simpler mathematical model to understand global climate change.He believes that the existence of the sea“Thermal inertia”The response to external influences such as greenhouse gases has lagged behind. The trend of global warming in this century is just the result of previous greenhouse gas emissions.
It is predicted that by 2400, the composition of greenhouse gases already existing in the atmosphere will increase the global average temperature by at least 1 ℃;The continuous emission of greenhouse gases will lead to an additional increase of 2 to 6 ℃ in the global average temperature.These two factors will also cause the sea level to rise by 10 cm and 25 cm per century respectively.To curb the trend of climate warming, it is necessary to control the global greenhouse gas emissions at an extremely low level. Even so, the trend of sea level rise may be unavoidable, and the rising speed of 10 cm per century may be the most optimistic prediction.
The second paper published by Gerald Mayer and others predicted that, due to the existence of "thermal inertia", even if mankind did not emit any greenhouse gases into the atmosphere in this century, the global average temperature would rise by at least 0.5 ℃ by 2100, and the sea level would rise by more than 11 cm, with the rise rate of the middle sea level more than double the earlier prediction of scientists.Mel explained that this is because the previous prediction did not take into account the impact of glacier melting.
Mel's research team used two sets of mathematical models to simulate the climate and sea level changes when the global greenhouse gas emissions were low, medium and high respectively with the help of supercomputers.
The latest research by Chinese scientists shows that there is an inevitable internal relationship between the continuous reduction of vegetation cover on the earth's surface and global warming. First, this more scientific mathematical model is briefly introduced.
First of all, we must introduce some simple physical knowledge:
1、 Mechanics
2、 Joule's law
The British physicist Joule did a lot of experiments. In 1840, he was the first to accurately determine that the heat generated by the current passing through the conductor is proportional to the second power of the current, to the resistance of the conductor, and to the power on time. This law is called Joule's law.Joule's law can be expressed by the formula Q=I ^ 2Rt
3、 Photoelectric effect
When light shines on some substances, it causes changes in the electrical properties of substances, that is, light energy is converted into electrical energy.This kind of phenomenon is called photoelectric effect.Photoelectric effect is divided into photoelectron emissionPhotoconductive effectandPhotovoltaic effect。The former phenomenon occurs on the surface of objects, also known asExternal photoelectric effect。The latter two phenomena occur inside the object, calledInternal photoelectric effect。Hertz discovered the photoelectric effect in 1887,EinsteinThe first successfully explained the photoelectric effect.
In short, it is actually the four major mechanics of force, heat, light and electricity, modern physics and other theories, as well as some knowledge of advanced mathematics, geological tectonic plate movement and other aspects.
With this knowledge, you can understand the following words
(1) Major premise
The earth rotates around the sun at the same time. The angle between yellow and red is 23 degrees and 26 minutes. Under the irradiation of solar radiation, due to the photoelectric effect, the electrons of the surface objects are continuously ionized, and the formed negative ions rise with the hot air, making the surface positively charged. The charge is linearly related to the intensity of solar radiation and time, that is,The sun is constantly charging the surface with positive charges, while the negative charges rise to the high altitude. The entire surface and atmosphere form a super giant capacitor.
⑵ How will the charge be distributed on the surface?
Since the sea water is a good conductor, in contrast, the continental plate is a bad conductor, so the charge can flow rapidly at sea level, while it flows relatively slowly on the continent. Due to the tip effect, the charge will continue to gather in areas with higher elevations on the earth's surface. Therefore, the total current effect at sea level is zero, and the current effect will be mainly reflected in the continental plate.In this way, a current and charge model of the earth can be established according to the basic parameters such as the distribution of the earth plate, the detailed topography of the surface, the rotation of the earth, and the angle of solar radiation. The distribution can be calculated. In theory, the results can be very consistent with the reality, the accuracy of parameter selection, and the data processing ability of the computer.
⑶ Distribution of current field and generation mechanism of geomagnetic field
When one side of the earth faces the sun, according to this theoretical model, if the external solar radiation is completely shielded, the movement trend of the charge on the earth surface is to continuously move to the tip zone, producing a current field 1,It is called magnetic field 1 (this current field is related to the distribution of the surface continent and the elevation of the continent, and the current is isotropic, so its overall effect is zero, but it can affect the distribution of the geomagnetic field in local areas);At the same time, the earth's surface is constantly discharging. Therefore, in the presence of solar radiation, the charge distribution on the side of the earth facing the sun (mainly distributed on the continent) is the most in the east and the least in the west (because the earth rotates from west to east). Therefore, a current from east to west is formed on the side facing the sun, which is called current distribution 2. This current generates a magnetic field,It is called magnetic field 2, and it can be seen that the magnetic field is strong on the side facing the sun, and the magnetic field diverges on the side facing away from the sun;In addition, the magnetic field generated by the positive charges accumulated in the tip of the earth's surface along with the earth's rotation can be called magnetic field 3;The negative charge above the earth's surface also generates current field 4 with the rotation of the earth, corresponding to a magnetic field, which can be called magnetic field 4. Since the total amount of positive and negative charges is equal, the overall effect of magnetic field 3 and magnetic field 4 is zero.To sum up, magnetic field 2 is the main source of the geomagnetic field, and the specific data should be based onsolar radiationThe detailed data such as the situation, the distribution of the continental plate and so on are modelled and calculated.
The earth can be regarded as a supercapacitor. While the sun continues to charge the supercapacitor with 1800A, it is also discharging 1800A (see Feynman's physics lecture on the average lightning current 1800A, which can be inferred that the charging current is 1800A). This discharge is lightning. Therefore, the average lightning current on the earth in the 20th century is 1800A,The lightning current is from the ground to the high altitude, from bottom to top.Lightning needs to break through the air, so it often occurs in areas with high air humidity, such as rainy and windy weather, and volcanic craters at higher elevations.The surface electric field intensity of the earth is more than 100V/m from bottom to top (see Feynman Physics handout). The electric field distribution should be from the surface to the ionosphere. Therefore, it can be inferred that the earth is a super capacitor with a lot of energy.sinceCharge quantityBig, why don't we feel it?Because we are located at the same potential, and dry air is an excellent insulator, so we have no feeling.
⑸ What will happen if the surface vegetation decreases?
From the above points, we can see that the large capacitance of the earth is a balance system.For a long time, the ecological environment and vegetation coverage on the earth have been relatively stable, so the water content of the surface is relatively stable, so the conductivity of the surface is relatively stable.According to this theory, when the vegetation on the local surface decreases, the conductivity of the surface decreases, that is, the resistance increases, that is, the internal resistance of the earth capacitor increases, while the charging power, that is, the solar radiation, is relatively stable. According to the Joule Law, this increases the heat generation on the surface to a certain extent, and promotes global warming to a certain extent.
(6) What will happen if a large number of surface vegetation disappears or a large-scale drought occurs?
For example, a large amount of vegetation disappears or is dry for thousands of kilometers around, causing large areas of the surface to become insulators, making it impossible to flow according to the original current field and a large number of charges gather on the surface.Because of theCoulomb forceIt is intuitively shown as the formation of cracks on the land surface, macroscopically shown as the tension of the continental plate where it is located, and the energy form isElastic potential energy。The longer the drought, the greater the energy accumulation.When the humid air moves to this area, due to the wetness of rain, the earth becomes a good conductor again, and a large amount of charges accumulated on the surface quickly move to the tip, so it rains cats and dogs, accompanied by a large number of lightning, and energy is released rapidly, causing abnormal movement of the continental plate.This energy release is insignificant for the earth, but it is devastating for human beings.
It can be seen from this model that the continuous decrease of surface vegetation is one of the main driving forces of global climate anomalies. While the surface temperature is slowly rising, various abnormal weather phenomena are also increasingly frequent, which have complex interactions and require more and more detailed data, such as atmosphere, ocean current, geology, etc. This model can be used asgeophysicsThe basic model of.Specific analysis of specific problems can also be extended to other celestial bodies and galaxies.
Fossil energyOn the one hand, a large number of acid rain has caused greenhouse gas emissions, on the other hand, a large number of acid rain has reduced vegetation, and the dual role of acid rain has aggravated the climate.
Ocean changes
Ocean changes
When it comes to climate change, sea level rise is very eye-catching news.In fact, the sea is not the same level. The sea level height in different parts of the sea is not the same, and the sea height can vary considerably between different oceans.What humans care about and observe is actually the coastal sea level.Affect the coastSea level changeThere are many factors, such as tide, weather, climate change, and the rise and fall of land itself. Of course, different factors have differenttime scale 。
Global warming causes ice and snow melting
The observation of coastal sea level changes by humans is very early, of course, the representativeness of early data is generally insufficient.mediterranean seaThe data of is better. It is observed that during the long period from the 1st century to 1900, the sea level change in the Mediterranean Sea did not exceed plus or minus 25 cm, or was basically stable;During this period, the change rate of sea level rise and fall in the Mediterranean Sea is basically between 0 and 2 mm per year.In modern times, in the second half of the 19th century, tide gauges were available on all major ocean surfaces in the world, so that the monitoring data of all ocean surface heights were available.In these historical data, obvious trend of accelerated sea level rise can be found, but the data is not enough for quantitative analysis.The comprehensive and systematic data recording of tide gauges began in 1961. It was observed that the average rate of global sea level rise was 1.8+- 0.5 mm per year from 1961 to 2003. During this period, the sea level was not simply rising, but rising and falling in some years.More comprehensive sea level data began from satellite measurement in 1993. In theory, satellite observation can obtain the most direct sea level observation data.According to satellite observation, the global sea level rose at a rate of 3.1+- 0.7 mm per year from 1993 to 2003, significantly faster than before.But this acceleration is only a short-term change, there is still a long-term trend, and it is not easy to draw a conclusion.From the records of tide gauges, the sea-level rise rate from 1993 to 2003 has occurred since the 1950s, which is not unique.
Like many climate problems, although the global sea level has shown an overall upward trend, the sea level changes in each ocean are different.It is observed that since 1992, the largest sea level rise has occurred in the western Pacific Ocean and the eastern Indian Ocean. The sea level of the entire Atlantic Ocean is basically rising except for some parts of the North Atlantic Ocean, but in some parts of the eastern Pacific Ocean and the western Indian Ocean, the sea level is actually declining.If you are interested, you can pay attention to the location of several small island countries that are making a lot of noise to see whether the problem really exists and is really urgent for them.The situation is quite different in different island countries.
Cause analysis
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There are two reasons for global warming:
1. The atmosphere has been damaged, seriously polluted and the greenhouse effect.
The system of atmosphere and surface is like a huge "glass greenhouse", which keeps the surface of the earth at a certain temperature all the time, creating an environment suitable for human and other living things.In this system, the atmosphere can not only let the solar radiation penetrate to the ground, but also prevent the loss of ground radiation. We call this protection of the atmosphere on the ground the greenhouse effect of the atmosphere.The gases that cause the greenhouse effect are called "greenhouse gases". They can let the short wave radiation of the sun pass through freely, and at the same time, they can absorb the long wave radiation from the ground.These gases include carbon dioxide, methane, chlorofluorocarbon, ozone, nitrogen oxides and water vapor, among which carbon dioxide is the most important.The global climate is gradually warming in the past hundred years. At the same time, the content of greenhouse gases in the atmosphere is also increasing rapidly.Many scientists believe that the intensification of the greenhouse effect caused by a large number of greenhouse gas emissions may be the basic reason for global warming.
Human beings emit a large amount of carbon dioxide into the atmosphere by burning fossil energy (such as coal, oil and natural gas).Among these fossil energies, coal has the highest carbon content, followed by oil and natural gas.In addition to direct combustion, carbon dioxide and methane will also be released during the exploitation of fossil energy, such as coal mine gas and natural gas leakage.Some activities in industrial production, such as cement, lime and chemical production, also emit carbon dioxide.In addition, in agriculture, such as rice fields and the digestion of ruminants (such as cattle and sheep), methane will be released.In addition, mankind has changed the way of land use, reducing the absorption of carbon dioxide by the atmosphere.Waste disposal also releases methane and nitrous oxide.These activities led to the increase of carbon dioxide and methane in the atmosphere, which led to global warming, broke the balance of the carbon cycle, and changed the form of energy conversion in the Earth's biosphere.Since the industrial revolution, the content of carbon dioxide in the atmosphere has increased by 25%, far exceeding all records in the past 160000 years.And there is no sign of slowing down.
2. Climate change is also related to population expansion, overload, over reclamation, deforestation, and indiscriminate exploitation of groundwater.
In recent years, the sharp increase of population is one of the main factors leading to global warming.At the same time, it also seriously threatens the balance between the natural ecological environment.The annual carbon dioxide emissions of such a population alone will be an astonishing number, which will directly lead to the continuous increase of carbon dioxide content in the atmosphere, and the carbon dioxide "greenhouse effect" formed in this way will directly affect the global warming.[21-26]
The current global average temperature is about 1.09 ℃ higher than that before industrialization.Among them, fully mixed greenhouse gases (GHG) may cause the temperature to rise by 1.0 ° C to 2.0 ° C, while other human drivers (mainly aerosols) cause the temperature to fall by 0.0 ° C to 0.8 ° C, natural (solar energy and volcanoes) drivers cause the global surface temperature to change by – 0.1 ° C to+0.1 ° C, and internal variability causes the global surface temperature to change by – 0.2 ° C to+0.2 ° C.[27]
greenhouse gases
Greenhouse gases are transparent to sunlight, so they can pass through the atmosphere to heat the earth's surface.The earth radiates it in the form of heat, and greenhouse gases absorb some of it.This absorption slows the rate of heat escaping into space, trapping heat near the earth's surface and warming it over time.[28]
Although water vapor (about 50%) and cloud (about 25%) are the largest contributors to the greenhouse effect, they mainly change with temperature changes, so they are mostly considered as feedback items for adjusting climate sensitivity.On the other hand, carbon dioxide (≈ 20%), tropospheric ozone[29]The addition or removal of gas concentrations such as CFC and nitrous oxide is independent of temperature, so it is considered as an external force to change the global temperature.[30]
Before the industrial revolution, a large number of greenhouse gases generated naturally led to the air temperature near the surface being about 33 ° C higher than that without greenhouse gases.[31-32]Human activities since the industrial revolution have mainly focused on extracting and burning fossil fuels (coal, oil and natural gas),[33]It increases the content of greenhouse gases in the atmosphere, resulting in radiation imbalance.By 2019, the concentration of carbon dioxide and methane has increased by about 48% and 160% respectively since 1750.[34]These CO2 levels are higher than at any time in the past 2 million years.Methane concentrations are much higher than in the past 800000 years.[35]
The global anthropogenic greenhouse gas emissions in 2019 are equivalent to 59 billion tons of carbon dioxide.Among them, 75% is carbon dioxide, 18% is methane, 4% is nitrous oxide, and 2% is fluoride gas.[36]Carbon dioxide emissions mainly come from burning fossil fuels to provide energy for transportation, manufacturing, heating and electricity.[40]Additional carbon dioxide emissions come from deforestation and industrial processes, including chemical reactions that produce cement, steel, aluminum and fertilizers.[37]Methane emissions come from livestock, dung, rice planting, landfill, wastewater, coal mining, and oil and gas mining.[38]The emission of nitrous oxide mainly comes from microbial decomposition of fertilizer.[39]
Although methane can only exist in the atmosphere for 12 years on average, carbon dioxide exists for a much longer time.[41]As part of the carbon cycle, the Earth's surface absorbs carbon dioxide.Although land and marine plants absorb most of the excess carbon dioxide emissions annually, when biomass is digested, burned or decayed, these carbon dioxide returns to the atmosphere.[42]Land surface carbon sink processes, such as carbon fixation and photosynthesis in soil, eliminate about 29% of global carbon dioxide emissions annually.[43]In the past 20 years, the oceans have absorbed 20 to 30 per cent of carbon dioxide emissions.[44]Carbon dioxide can only be removed from the atmosphere for a long time if it is stored in the earth's crust. This process may take millions of years to complete.[42]
Surface change
According to the Food and Agriculture Organization of the United Nations, about 30% of the earth's land area is basically unfit for human use (glaciers, deserts, etc.), of which 26% is forests, 10% is shrubs, and 34% is farmland.[45]Deforestation is the main land use change factor leading to global warming,[46]Because the destroyed trees will release carbon dioxide, and will not be replaced by new trees, thereby reducing the carbon sink.Between 2001 and 2018, 27% of deforestation was caused by permanent deforestation to expand agricultural expansion of crops and livestock.Another 24% was lost due to temporary clearing under the rotation farming system.26% is caused by logging of wood and derivatives, and the remaining 23% is caused by wildfire.[47]Some forests have not yet been completely cut down, but have been degraded due to these effects.[48]
The local vegetation coverage can affect the albedo of the surface and the heat loss due to evaporation.For example, changes from forest to grassland make the surface brighter, reflecting more sunlight.Deforestation can also change the release of chemicals, indirectly affecting clouds and wind.[49]In tropical and temperate regions, the net effect is to produce significant warming, so restoring forests can reduce the local temperature.[48]At latitudes near the poles, when forests are replaced by snow covered (and more reflective) plains, a cooling effect will occur.[49]Globally, the increase of surface albedo is the main direct impact of land use change on temperature.Therefore, land use change so far is estimated to have a slight cooling effect.[50]
Aerosols and clouds
The pollutants in the air affect the climate on a large scale in the form of aerosols.[51]Aerosols scatter and absorb solar radiation.From 1961 to 1990, the amount of sunlight reaching the earth's surface gradually decreased, mainly due to sulfate aerosols produced by the combustion of fossil fuels with high sulfur content, such as coal and marine fuels.Smaller contributions come from black carbon, organic carbon produced by the combustion of fossil fuels and biofuels, and anthropogenic dust.[52-55]Globally, due to pollution control, aerosols have been decreasing since 1990, which means they no longer cover up greenhouse gas warming.[56]
Aerosols also have an indirect impact on the Earth's energy budget.Sulfate aerosols act as cloud condensation nodules, and they can reduceGrowth of raindrops, resulting in more and smaller cloud droplets.These clouds reflect solar radiation more effectively than clouds with fewer and larger water droplets.[57]The indirect influence of aerosol is the biggest uncertainty of radiative forcing.[58]
Although aerosols usually limit global warming by reflecting sunlight, black carbon may cause global warming.They will not only increase the absorption of sunlight, but also increase the melting of glaciers and sea level rise.[59]Limiting new black carbon deposition in the Arctic by 2050 can reduce global warming by 0.2 ° C.[60]
Solar and volcanic activity
Since the sun is the main energy source of the earth, the change of incident sunlight directly affects the climate system.[58]The solar irradiance has been directly measured by satellite,[61]Indirect measurements have been available since the early 1600s.[58]Since 1880, the solar energy reaching the Earth has not shown an upward trend, which is in sharp contrast to the warming of the lower atmosphere (troposphere).[62]
Volcanic eruptions can release gas, dust and ash, partially blocking sunlight and lowering temperature, or release water vapor into the atmosphere, thus increasing greenhouse gases and raising temperature.[63]But the impact on temperature will only last for a few years, because the persistence of water vapor and volcanic materials in the atmosphere is very low.[64]The impact of volcanic carbon dioxide emissions is more lasting, but it is less than 1% of the current carbon dioxide emissions caused by humans.[65]Volcanic activity is still the largest natural forcing factor for temperature in the industrial age.However, like other natural forces, since the Industrial Revolution, its impact on global temperature trends can be ignored.
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global warming
In the 20-21 century, the global average temperature has experienced four fluctuations: cold → warm → cold → warm. On the whole, the temperature is on the rise.Since the 1980s, the global temperature has risen significantly.In the 21st century, the average temperature in the Arctic has risen by more than 1.6 ℃.
The system of global atmosphere and surface is like a giant“Glass greenhouse", so that the earth's surface always maintains a certain temperature, creating an environment suitable for the survival of human beings and other creatures. In this system, the atmosphere can not only allow solar radiation to penetrate to the ground, but also preventGround radiationWe call the protective effect of the atmosphere on the ground atmosphericgreenhouse effect。The gases that cause the greenhouse effect are called“greenhouse gases", they radiate solar shortwavevisible light(3.8~7.6 nm, short wavelength) has high penetrationLong wave radiation(e.g. infrared) highly absorbent.These gases include carbon dioxide, methane, chlorofluorocarbon, ozone, oxides of nitrogen andsteamAmong them, carbon dioxide is the most closely related to people.In the past century, the global climate is gradually warming, at the same time, the content of greenhouse gases in the atmosphere is also increasing rapidly.Many scientists believe that the intensification of the greenhouse effect caused by the massive emission of greenhouse gases is the basic reason for global warming.
Human beings burn coal, oil, natural gas and trees, producing a large amount of carbon dioxide and methane into the atmosphere, warming the earthcarbon cycleThe imbalance has changed the energy conversion form of the Earth's biosphere.sinceindustrial revolutionSince, in the atmosphereCarbon dioxide contentIt has increased by 25%, far exceeding all the historical records of the past 160000 years that scientists may survey, and there is no sign of slowing down.
The increase of carbon dioxide emissions in the atmosphere is the root cause of global warming.International Energy Agency The survey results show that the carbon dioxide emissions of the United States, China, Russia and Japan account for almost half of the global total.The survey shows that the United States ranks first in the world in terms of carbon dioxide emissions, with an annual per capita carbon dioxide emissions of about 20 tons, accounting for 23.7% of the global total.China's annual per capita carbon dioxide emissions are about 11.73 tons, accounting for 13.9% of the global total.
In June 2023, 50 top scientists published a paper on the latest issue of Earth System Science Data, saying that in the past 10 years, global greenhouse gas emissions have reached a "historical high", with an annual emissions of 54 billion tons of carbon dioxide, leading to global warming at an unprecedented rate.[13]
UN measures after warming
In order to prevent global warming, the United Nations specially formulated the United Nations Framework Convention on Climate Change in 1992, which came into force in the Brazilian city of Rio de Janeiro in the same year.According to the Convention, developed countries agreed to reduce their emissions of carbon dioxide and other "greenhouse gases" into the atmosphere to 1990 levels by 2000.In addition, these countries whose total annual carbon dioxide emissions account for 60% of the total global carbon dioxide emissions also agreed to transfer relevant technology and information to developing countries.The technology and information transferred from developed countries to developing countries will help the latter to actively respond to the challenges posed by climate change.[3] As of February 2024, almost all countries in the world are members of the Convention.The 198 States that have ratified the Convention are called parties to the Convention.[16]
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Basic Introduction
one
The heat energy brought by the rising temperature will provide huge kinetic energy to the air and ocean, which will lead to large-scale, even super large-scale typhoon, hurricane, tsunami and other disasters.More and more disasters are suffered and faced every year, and the number of lives and money lost is increasing, which is more and more unacceptable.[3]Disasters such as typhoons and tsunamis not only directly damage buildings and threaten human life safety, but also bring secondary disasters, especially the heavy rainfall caused by disasters such as typhoons and hurricanes, which will lead to debris flows, landslides, etc., seriously threatening traffic safety and residents' life safety.[3]
two
The rising temperature will not only absorb water directly from the sea, but also from the land, making a large area of drought in inland areas, thus reducing grain production and feed production.Food and meat products will be in short supply, directly threatening national stability.Panic and fighting over food will no longer happen in backward villages.
three
The icebergs melted by the rising temperature are the main source of fresh water for our survival.Most of our underground fresh water reserves come from iceberg melt water.When the temperature balance is normal, the ice and snow circulation system of the iceberg, that is, the iceberg melts in summer, flows down the mountain and underground, accumulates fresh water for the plain area, and plays a filtering role.In winter, water returns to the mountain in the form of steam, and accumulates ice and snow again through a large amount of snowfall, which is also a filtering process.The whole circulation process ensures the stability and balance of our fresh water.But now global warming makes the accumulation of icebergs and ice snow far less rapid than the melting speed, and even some icebergs no longer accumulate, which has cut off the local drinking water.This will lead to conflicts and wars due to water shortage.
four
The rising temperature makes the natural food chain gradually break.
five
The increase of carbon dioxide content in the atmosphere will lead to the increase of carbon dioxide content in the ocean, which will lead to the carbonation of the ocean, which will kill a large number of microorganisms.Rising ocean temperature will also destroy a large number of coral centered biological chains.The food at the bottom disappears, so that the marine food chain starts from the bottom, breaks up rapidly and spreads out of the sea.Because there is no food, there will be a large number of marine organisms, and other organisms that feed on marine organisms will die.The death of a large number of living things in the sea will pollute the sea and accelerate the death of other living things;At the same time, a large number of greenhouse gases are released to accelerate global warming and form a vicious circle.
six
As the temperature rises, invertebrates, especially insects, wake up early from hibernation, while long-distance migratory animals relying on these insects cannot catch up in time, miss the opportunity to prey, and thus die in large numbers.Insects wake up in advance, because there is no natural enemy, they will eat large forests and crops without fear.Without forests, the content of carbon dioxide is increased invisibly, accelerating global warming and forming a vicious circle;Without crops, human beings have no food.
seven
The decrease in the number of bees is also a precursor to the complete collapse of the natural food chain.Without bees to help spread pollen, plants would not be able to reproduce.In other words, crops cannot reproduce and bear fruit, and humans will have no food.Global human beings will face food shortage, and the wars for food will become more and more and closer.And the food for human competition will be less and less.
eight
Global warming causes a large loss of water on land, and there will be "a single spark can start a prairie fire" at any time.Not only the forest fires, but also the urban fires will be very frequent.The fire is merciless, and our home will be in danger for 24 hours.24 hours, that is to say, even at night, there is a possibility of fire.See Canadian wildfires.
nine
The film "The Day After Tomorrow" describes that global warming will lead to the sudden collapse of the Atlantic meridional overturning circulation.AMOC represents the Atlantic meridional overturning circulation.AMOC has established a water cycle from south to north in the Atlantic Ocean in a long cycle.This cycle brings warmth to all regions of the world and carries the nutrients needed to sustain marine life.When warm water near the surface moves toward the poles (such as the Gulf Stream in the North Atlantic), the cycle begins, where it cools and forms sea ice.With the formation of ice, salt will remain in the sea water.Because the water contains a lot of salt, it becomes denser, sinks, and moves south in the depths below.Eventually, the water is pulled back to the surface and heated up in a process called upwelling, completing the cycle.[17]AMOC is marked as one of the tipping elements in the climate system[18-19], indicating that it may experience relatively rapid changes under the force of slow development.AMOC is particularly sensitive to marine freshwater forcing, whether through surface freshwater flux (e.g. precipitation) or freshwater input due to river runoff or ice melting (e.g. from the Greenland ice sheet).[20]Although research shows that it is weakening in the past century, it is still uncertain whether it will continue to slow down or completely stop the cycle.However, if AMOC continues to slow down, it may have far-reaching climate impacts.[17]In a study in 2024, climate models give some possible consequences.The sea level along the Atlantic coast will rise by one meter in some areas, flooding many coastal cities.The rainy and dry seasons of the Amazon will reverse, which may push the weakened tropical rainforest to its own critical point.The fluctuation of global temperature will become more unstable.The temperature in the southern hemisphere will rise.Europe will experience a sharp cooling, while the rainfall will decrease, and the cooling rate will be ten times the current warming trend.[20]
ten
The rising temperature will affect human physiological functions, and the probability of illness will increase. Various physiological diseases will spread rapidly, and even breed new diseases.Eye diseases, heart diseases, respiratory diseases, digestive diseases, viral diseases, bacterial diseases... The society will pay more and more money for medical treatment, and more and more people will die unexpectedly.Cancer will become more and more popular;Sudden death will become more and more common.
eleven
The rising temperature, melting glaciers and rising sea level have caused the loss of coastal wetlands, mangroves, coral reefs and other ecological groups, coastal erosion, seawater intrusion into the coastal groundwater layer, coastal land salinization, etc., resulting in the imbalance of the natural ecological environment of the coast, estuaries and bays, and bringing disasters to the ecological environment of the coastal zone.
twelve
The water area increases.Water evaporation is also increasing, the rainy season is prolonged, and floods are becoming more and more frequent.The chance of flooding is increased, the degree and severity of storm impact are increased, and the service life of the reservoir dam is shortened.
thirteen
Temperature rise will affect human fertility, and sperm activity will decrease with temperature rise.
fourteen
Bacteria pass extreme weather and climate events（el nino phenomenon，La Nina phenomenon, drought, flood, heat wave, etc.), and the spread of the epidemic is very harmful to human health.
Terrible consequences of global warming
climate
The greenhouse effect has been working since the formation of the earth.Without the greenhouse effect, the earth's surface would be extremely cold, the temperature would drop to minus 20 ℃, the oceans would freeze, and life would not form.Therefore, what we are facing is not the problem of whether there is greenhouse effect, but that human beings burnfossil fuelA large number of greenhouse gases are discharged into the atmosphere, causing the greenhouse effect and the earth's climate to change dramatically.
What impact will the greenhouse effect have?Due to the burning of fossil fuels and massive deforestation, the concentration of carbon dioxide and other gases in the earth's atmosphere has increased. Due to the greenhouse effect of these gases, the global average ground temperature has increased by about 0.3~0.6 ℃ in the past 100 years, and it is estimated that it will increase by 1~3 ℃ by 2030.
When the average temperature of the world rises by 1 ℃, huge changes will occur: sea level will rise, mountain glaciers will retreat, and snow covered areas will shrink.As the global temperature rises, it will lead to uneven precipitation, which will increase in some regions and decrease in others.For example, the Sahel region in West Africa has experienced severe drought since 1965;Since 1965, the precipitation in North China has decreased year after year. Compared with the 1950s, the precipitation in North China has decreased by 1/3, and the water resources have decreased by 1/2;The area affected by drought in China is about 400 million mu every year. In normal years, irrigation areas across the country are short of 30 billion cubic meters of water every year, and cities are short of 6 billion cubic meters of water.When the average temperature of the world rises by 3 ℃, human beings have no way to recover, and the world will be short of food.Due to the rising temperature, the global sea level has been rising at the rate of 1~2mm every year in the past 100 years. It is estimated that the sea level will continue to rise by 30~50cm by 2050, which will flood a large number of low-lying coastal land;In addition, climate change has led to the intensification of drought, flood, low temperature and other climate disasters, resulting in economic losses of more than tens of billions of dollars every year around the world.
Global warming has increased precipitation in the mainland, especially in the middle and high latitudes, and reduced precipitation in Africa and other regions.Extreme weather and climate events (El Nino, drought, floodthunderstorm、hail、storm, high temperature weather, sand storm, etc.).
glacier
The melting speed of Antarctic glaciers is accelerating
Since the 1920s, people have observed the melting of glaciers in the Alps from Patagonia to Switzerland due to "greenhouse" gas emissions and the generally recognized greenhouse effect.In South Asia, the question is not whether glaciers are melting, but how fast?Although many adverse effects of global warming may not become very serious until the end of the 21st century, NepalIndia、Pakistan、ChinaandBhutanMelt water from glaciers in other places may soon cause trouble to people.
International Ice and Snow CommissionA research report of ICSI pointed out that: "The glaciers in Himalaya retreat faster than any other region in the world. If the current melting rate continues, these glaciers are very likely to disappear before 2035.".Said Said Hassnen, head of the International Ice and Snow Commission, "Even if the glacial melt water dries up in 60 to 100 years, the scope of the impact of this ecological disaster will be shocking."
The glaciers in the eastern Himalayas, located in the Ganges River basin, are melting most seriously, and those distributed on the "roof of the world" from Bhutan to Kashmir are retreating fastest.Take the 3-mile Balnak Glacier as an example. This glacier is one of many glaciers formed by the collision between the Indian subcontinent and the Asian continent 40 million to 50 million years ago. Since 1990, it has retreated by half a mile.After the severe sub Arctic winter in 1997, scientists had predicted that the glacier would expand, but it retreated further in the summer of 1998.
ecology
First, global warming has led to sea level rise and redistribution of precipitation, changing the current world climate pattern;Secondly, global warming has affected and destroyed the biological chainfood chainAnd bring more serious natural consequences.For example, there is a kind of migratory bird that flies from Australia to Northeast China for summer every year. However, due to the global warming, the temperature in Northeast China has increased, and the summer has prolonged, so the time for this bird to leave Northeast China has correspondingly delayed, and the time for it to return to Northeast China has correspondingly delayed.As a result, a kind of pest eaten by this migratory bird became rampant and destroyed a large area of forest.In addition, extreme events related to the environment have increased, such as drought and flood.
Politics
Limiting carbon dioxide emissions is equivalent to limitingenergyThe consumption of will have a restrictive impact on countries around the world.Whether to "reduce emissions" in developing countries or in developed countries has become the focus of discussion among countries.The greenhouse gas emissions of developing countries are increasing, and the issue of "emission reduction" after 2013 will inevitably focus on developing countries.The scientific issue of preventing global warming will inevitably lead to the issue of "North South relations", thus making the climate issue an international political issue.
ocean
With the rise of global temperature, the amount of water vapor evaporated in the ocean has increased significantly, which has aggravated the warming phenomenon.The decrease of the total heat capacity of the ocean can restrain the global warming.In addition, due to the fact that the oceanatmosphereIt releases excessive carbon dioxide, so the real culprit is the plankton community in the ocean.
crops
The impact of global warming on crop growth has both advantages and disadvantages.First, global temperature changes directly affect the global water cycle, causing drought or flood in some areas, leading to crop yield reduction, and too high temperature is not conducive to seed growth.Second, the increase in precipitation, especially in arid areas, will actively promote crop growth.The increase of carbon dioxide content accompanied by global warming will also promote the photosynthesis of crops, thus increasing production.Third, the increase of temperature is conducive to the increase of yield of crops in high latitudes that like humidity and heat.
Biology
Discovery of new life in Antarctica
New Species Emerged in Antarctic due to Global Warming
As global warming has led to the collapse of two major ice shelves in Antarctica, an area of 10000 square kilometers of seabed has been exposed. Scientists from 14 countries have been able to discover many unknown new species, look at the pictures of these strange creatures, and feel the magic of nature.
For example, creatures like octopus, coral and shrimp.The researchers classified 1000 species of life in the Antarctic seabed area.Researchers believe that the continuous global warming causes the AntarcticIce shelf disintegrationThus affecting the living environment of marine organisms.
Discovery of new life in Antarctica
During the 10 week Antarctic exploration, the Global Scientific Expedition Team made the first comprehensive observation of the seabed creatures using the remote control work vehicle.Before the collapse of the ice shelf, the only way for scientists to observe was by drilling holes in the ice layer.For thousands of years, AntarcticaWeddell SeaThe 10000 square kilometers of seabed is covered by 100 meters of Larsen A ice shelf and Larsen B ice shelf.In recent years, these ice shelves began to collapse, so many new species appeared in the world's most primitive ecological sea area.
One of the main purposes of this scientific expedition is to explore the native life forms in Antarctica and study the new biological types generated after the collapse of the ice shelf.Julian Gutt, a scientist, said that 95% of the creatures in this discovery were native to Antarctica, and the other 5% were born after the collapse of the ice shelf.
human health
Paul Epstein of the Institute of New and Recurrent Diseases at Harvard University noted that plants also move with the snow line, and plants on mountains around the world are moving up.With the warming of mountain peaks, the environment at higher altitude is more and more conducive to the survival of mosquitoes and malaria parasites they carry.
West Nile virus、malaria、yellow feverSince 1987, other tropical infectious diseases have broken out in Florida, Mississippi, Texas, Arizona, California, Colorado and other places in the United States, which has repeatedly confirmed the scientific inference of experts that climate warming will spread some tropical diseases to cooler areas.
Iceberg melting
Scientists have found that if global temperatures continue to rise, the melting of Arctic icebergs will release a large number of toxic chemicals trapped in ice and cold water.Researchers warn that the large amount of poisons gathered in the polar regions are unknown, and their release will seriously endanger marine life and human survival environment.These chemicals that will leak out include pesticides DDT, chlordane, etc.All of this is continuousOrganic pollutants, or it may cause cancer and congenital defects, which were previously captured by the Arctic ice and frozen water.However, scientists in Norway and Canada found that global warming is making these pollutants "reborn" when monitoring the measurement results of organic pollutants in the air in 1993 and 2009.Haili Hong, a member of the research team, said: "The next step is to find out how many pollutants are leaking in the Arctic and at what speed."
Another research result on global warming is even more surprising. Due to the melting of the Arctic ice sheet, the increase of rainfall, and the continuous change of wind types, a large amount of fresh water is flowing into the North Atlantic Ocean, causing damage to the Gulf Stream, thus cutting offNorth Atlantic Warm Current。It is these warm currents that bring the warm surface water from the Caribbean Sea to the northwest of Europe, and form a warm climate in Europe.Once the North Atlantic Warm Current is cut off due to global warming, the temperature in northwest Europe may drop as much as 5~8 ℃, and Europe may face a newice age！
This research is based on the analysis of more than 17000 seawater salinity measurements between the waters of the Lan Islands and the Faroe Islands since 1893 by the Scottish Ocean Experiment in Aberdeen.Every 20 years before 2007Deep sea waterThe salinity is getting smaller and the concentration is getting lower, which indicates that more fresh water flows into the region from the north of the Atlantic Ocean.These new data fully proved the computer model designed by German scientists about 1993 for the first time.
The carbon dioxide content in the atmosphere has risen sharply, and the world population will reach 10 billion by 2050."Our world is moving towards replacing the existing free natural resources with man-made facilities",University of MinnesotaDavid Tillman said.However, we have not yet mastered the relevant knowledge of natural ecosystems.In the Permian extinction 245 million years ago, 96% of species died out.Later, with the emergence of many new species, the earth finally recovered a rich population, but this process has gone through 100 million years.Wilson said: "Some people believe that nature will revive everything destroyed by human beings.".As the saying goes, "As long as there is enough time, everything can come into being." Maybe nature can really recover everything, but this long process is meaningless for modern humans anyway.
The melting of ice and snow may be a good sign of the coming of spring in the minds of many people, but scientists concerned about climate change are worried to point out that global warming and the resulting accelerated melting of ice and snow are posing a serious threat to the survival of all mankind and other species.
From 2001 to 2020, global warming caused a total loss of 7684 billion tons of Antarctic ice sheet, Greenland ice sheet and Qinghai Tibet plateau glaciers,The total contribution to global sea level rise is about 21mm, accounting for about one-third of the total global sea level rise in the same period.[14]
human health
The latest research shows that more than 5 million deaths each year can be attributed to abnormal high and low temperatures.
This result is based onShandong UniversityprofessorZhao QiFirst author, published on July 8, 2021《Lancet》Subjournal《Lancet · Planet Health》（The Lancet Planetary Health）[8]Magazine.Corresponding author isMonash University, AustraliaProfessor, School of Public Health and Preventive MedicineGuo Yuming。It is reported that this is also the largest climate related mortality study in the world.
The results show that from 2000 to 2019, unsuitable outdoor temperature was associated with more than 5 million excess deaths each year, that is, 74 temperature related deaths per 100000 residents, accounting for 9.43% of the global total deaths, most deaths were caused by cold exposure, accounting for 8.52%, and excess deaths caused by high temperature accounted for 0.91%.Guo Yuming believes that the data of 9.43% is enough to show that the temperature andsmoke、hypertension、air pollutionLike other factors, it is a major threat to human health.
From the perspective of time, from 2000 to 2019, the death toll related to cold decreased by 0.51%, while the death toll related to high temperature increased by 0.21%, leading to a decrease in the net mortality rate caused by cold and hot temperatures.However, Guo Yuming warned that the mortality rate related to global warming will continue to increase in the long run due to the inevitability of climate change.[7]
Extreme heat wave
On August 9, 2021, the report issued by the United Nations Intergovernmental Panel on Climate Change (IPCC) pointed out that, due to global warming, the extreme heat wave, which used to occur once every 50 years, is now expected to occur once every 10 years, and torrential rains and droughts have become more frequent.[9]
Slow down warming
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Scientists have proposed an idea to build an artificial space ring composed of small particles or spaceships around the earth to block tropical sunlight and regulate the earth's temperature.
Some opponents believe that this idea will definitely have some side effects. A particle belt that can effectively scatter sunlight will make every night sky as bright as the full moon;And the budget will be surprisingly high, possibly reaching 6 trillion to 200 trillion US dollars, even the most adequately funded scientific research institutions in the worldNASAWe can't afford it. If we change scattering particles into spaceships, the budget may be less, and it is estimated that it can be reduced to about 500 billion dollars.
Since the birth of the earth, the atmospheric temperature has fluctuated several times, and various factors such as solar radiation, cloud cover and greenhouse gases have or are affecting our climate.If the earth is surrounded by a particle or a "belt" composed of spaceships, a shadow will appear over the equator. To deploy these particles, you must use some special control spaceships to look after the particle swarm like a shepherd dog.
NASA Satellite Mapping Shows Global Warming Trends
In the past century, the earth temperature has risen significantly, and this trend will continue in the next 100 years. Many studies have confirmed that the earth temperature will increase by 1~20 degrees Fahrenheit in the next few centuries, the sea level will rise significantly, and some coastal cities will no longer exist.Some scientists have pointed out that reducing sunlight will reduce the temperature of the earth, and some ground or space systems can fully achieve this goal.However, some scientists pointed out that it is still impossible to calculate how much sunlight the earth can absorb and how much sunlight is reflected back into space, which is a key step in implementing the above plan.
American research shows that the activities of ancient farmers prevented the world from entering a new glacial period.The results show that global warming caused by human activities is not a new phenomenon, it may last for thousands of years.The British Observer quoted researchers as saying that the prehistoric farmers who cut down trees and reclaimed the first piece of land had greatly changed the content of methane, carbon dioxide and other greenhouse gases in the earth's atmosphere, so the global temperature gradually rose.Weiqian Ladiman, a professor at the University of Virginia in the United States, said: "If it were not for the greenhouse gases brought by early agricultural activities, the current temperature of the earth would probably still be the temperature of the ice age." Research shows that without human intervention, the earth would be 2 ℃ lower than in the 20th century, and the spread of ice sheets and glaciers would affect most parts of the world.
The forests in the world are mainly divided into cold zone (northern) forests, temperate forests and tropical forests.It is reported that today'sForest ecosystemIt is the gradual formation of nature after 8000 years of evolution.Today, all primitive forests have become the target of large-scale exploitation and utilization of logging industry.In tropical areas, many forests that have disappeared in the 21st century have been cut down in the past 50 years.From 1960 to 1990 alone, more than 450 million hectares of tropical forests were devoured, accounting for 20% of the total area of tropical forests in the world;Millions of hectares of tropical forest are also degraded in deforestation, farmland reclamation and mineral exploitation.
In addition, the global illegal logging and illegal timber products trade continue to intensify, especially in developing countries with tropical forests and Russia, where the government does not enforce the law effectively.The demand for cheap wood products in the international market has further worsened this situation.
By 2100, the global temperature is estimated to rise by about 1.4~5.8 ℃ (2.5~10.4 degrees Fahrenheit).
Global warming propaganda cartoon
chemical element
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carbon dioxide
Carbon dioxide is colorless, slightly pungent and slightly sour at normal temperature and pressure.COtwoThe molecule has 16 valence electrons, and the ground state is a linear molecule, belonging to the D ∞ h point group.COtwoThe carbon oxygen bond length in the molecule is 116pm, between the carbon oxygen double bond (C=O bond length in acetaldehyde is 124pm) and the carbon oxygen triple bond (C ∨ O bond length in CO molecule is 112.8pm), indicating that it has a certain degree of triple bond characteristics.Therefore, it is believed that in COtwoThere may be delocalizedLarge π bondThat is, in addition to forming two bonds with oxygen atom, carbon atom also forms two big π bonds with three centers and four electrons.
Freon
Ozone depleting substances such as Freon are the culprits of ozone layer destruction. Freon was synthesized in the 1920s. Its chemical properties are stable, and it is not flammable and toxic. It is used as refrigerant, foaming agent and cleaning agent, and is widely used in household appliances, foam plastics, daily chemicals, automobiles, fire equipment and other fields.In the late 1980s, the production of Freon reached its peak, reaching 1.4417 million tons.Before the control of Freon, the amount of Freon discharged into the atmosphere all over the world had reached 20076900 tons.Since their average lifetime in the atmosphere reaches hundreds of years, most of the emissions still remain in the atmosphere, most of them still stay in the troposphere, and a small part rises into the stratosphere.Freon, which is quite stable in the troposphere, will be decomposed under the action of strong ultraviolet light under certain meteorological conditions after rising into the stratosphere. The chlorine atoms released from the decomposition will have a chain reaction with ozone, and constantly destroy ozone molecules.Scientists estimate that one chlorine atom can destroy tens of thousands of ozone molecules.
nitrogen
The element name comes from Greek, which originally means "saltpeter".In 1772, Swedish pharmacist Scheler and British chemistrutherfordAt the same time, it was found that it was later determined by French scientist Lavoisier to be an element.The content of nitrogen in the crust is 0.0046%. Most of the nitrogen in nature exists in the atmosphere in the form of simple molecular nitrogen, which accounts for 78% of the air volume.The most important mineral of nitrogen isNitrate。There are two natural isotopes of nitrogen: nitrogen 14 and nitrogen 15. The abundance of nitrogen 14 is 99.625%.
oxygen
Oxygen is usually a colorless, odorless and tasteless gas.exceptinert gasAll exceptchemical elementCan form compounds with oxygen.Most elements can form oxides when heated in an oxygen containing atmosphere.Many elements can form more than one oxide.Oxygen molecule can form hydrated crystal O at low temperaturetwo.HtwoO and Otwo.HtwoOtwoThe latter is more unstable.Oxygen is the basis of life in water.Oxygen is the most abundant in the crust.The dry air contains 20.946% oxygen by volume;Water is composed of 88.81% oxygen by weight.Except OsixteenBesides, there is OseventeenAnd OeighteenIsotopes.
Most injured country
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Tuvalu, a beautiful island country in the South Pacific, is likely to become the first country to "sink".The country's meteorological bureau calculates that in 50 years, the sea level will rise by 37.6 cm, which means that at least 60% of Tuvalu's territory will completely sink into the sea.This means the end of Tuvalu, because Tuvalu will not have any land exposed to the sea at high tide.
Due to the rising temperature, the Maldives, the "Xanadu" located in the Indian Ocean, has been dying for only a few years.On October 17, 2009, the cabinet of Maldives held the world's first "underwater cabinet meeting", highlighting the threat of global warming to the country.
Kiribati is the first place on earth to greet the sunrise, and it is also the only country in the world that spans the northern and southern hemispheres and the eastern and western hemispheres.However, with the global warming and sea level rise, it is also doomed to disappear there.On April 30, 2010, Kiribati had two islands engulfed by seawater, with the highest place only 6 feet above sea level.
Tanzania is located in the east of the African continent and faces the Indian Ocean in the east. The people there will also become the first group of "villagers" in the global village to bear the consequences of climate warming.The country's environment minister said: "The impact of climate change is becoming more and more obvious. 80% of the glaciers in Kilimanjaro have disappeared in the past 50 years."
Barbados, a Latin American country, is located in the East Caribbean Sea.Strong hurricanes, coral bleaching, beach erosion, water shortage... The temperature rise has brought too much trouble to this island country.
In 2009, the cabinet of the Nepalese government held a meeting on the hillside of Mount Everest, more than 5000 meters above sea level, to draw the world's attention to its problems.
Global warming has had a serious negative impact on Bangladesh, which is located in the lower terrain of the delta region, making it one of the most serious victims in the world.The Bangladeshi Foreign Minister said: "It is estimated that by 2050, 20 million Bangladeshis will choose to leave their homes under the influence of climate change."
Speaking about his country, Vietnam's Deputy Minister of Natural Resources and Environment said, "Flood, typhoon, drought and other disasters are becoming more and more frequent and serious. From this perspective, climate change has also affected Vietnam."
Kenya's minister in charge of water conservancy and irrigation said: "Due to the long-term drought, our country has suffered seriousWater shortageThe water distribution system will be implemented in Nairobi, the capital.As a chain reaction, hydropower has also been affected (70% of Kenya's electricity comes from hydropower), so power rationing has to be implemented nationwide. "
Bhutan faces a similar threat.The chairman of its environmental committee said: "Especially for mountainous countries like Bhutan, the river and lake breakwaters are likely to cause flood outbreaks at any time."
The Minister of Environment of Rwanda said: "As a country vulnerable to climate change, we need to have a full understanding of climate change and its negative impacts[4]。”
Dispute query
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In 2012, 16 scientists jointly published an article questioning the theory that carbon dioxide causes global warming.
In September 2011,Nobel PrizeWinner, physicistIvar Giaever Published an open letter announcing his withdrawalAmerican Physical Society, Jaeve wasObamaA supporter of the President.At the beginning of the letter, it said: "I have not renewed (my membership) because I disagree with some statements in the statement. The American Physical Society said: 'There is irrefutable evidence that global warming is taking place.If no action is taken to mitigate this trend, the physical and ecological systems, social systems, security and human health of the Earth may be seriously damaged.We must reduce greenhouse gas emissions from now on. "The American Physical Society can discuss whether the mass of protons will gradually change, and how the multi universe works, but is the evidence of global warming really irrefutable? "
Although more and more scientists openly question the climate warming theory, many young scientists privately say that although they are deeply suspicious of the global warming theory, they dare not say it because they are afraid that it will hinder their promotion, or even worse things will happen.Their concern is not unreasonable.In 2003, Dr. Chris de Freitas, editor of the academic journal Climate Research, boldly published a peer review article that did not conform to the political orientation (but was consistent with the facts). The article concluded that if the climate change in the past 1000 years was taken as the background, the recent climate warming was not an abnormal phenomenon.The international global warming theorists soon launched a deliberate attack on Dr. De Freitas, demanding that his editorial post and university teaching post be abolished.Fortunately, Dr. De Freitas kept his university teaching position.[5]
Cause objection
Comparison between US and global annual average temperature measurements
Richard Lindzen, an expert in Earth and Atmospheric Sciences at MIT Institute of Technology, is skeptical of this view.As early as 1991, Lindzen and the former Vice President of the United StatesThe Nobel Peace PrizeWinnerGoreA fierce debate broke out at the National Treasure Inquiry Meeting of the United States.Gore sat in Congress on climateenvironmental problemsIn the hearing, Lindzen is an academic expert who accepts the hearing.At the meeting, Lindzen strongly criticized Gore's understanding of global environmental issues is too one-sided and lacks some necessary research common sense.He believes that the earth's climate has been in the process of continuous change for a long time, during which there are various complex reasons, rather than just carbon dioxide emissions, as the supporters of "global warming" said.He was in 2007News WeekThe magazine pointed out that the fastest stage of global temperature rise in the 20th century was 1910~1940, and then ushered in a global cooling stage for 30 years, until 1978 when the global temperature began to rise again.If industrial carbon dioxide emissions are the main cause of global warming, how to explain the cooling stage between 1940 and 1978.As we all know, these three decades are the era when most of the world began the Great Leap Forward in large-scale industrialization, namely the so-called post-war boom era.
Timothy, Canada's first climatology doctor, wrote the article Global Warming: Is There Hard Data to Support? He said: "Someone mentioned that the rise of the average temperature of the earth would 'exceed the safety warning line of the earth's constant temperature'. Is there such a thing as the earth's constant temperature? Haven't he heard of the ice age?In the 1970s, the hot topic was global cooling, and in the 21st century, it was global warming. There would be disasters at low and high temperatures. Is the earth's temperature the best?“
March 8, 2007bbcThe documentary "Global Warming Trick" was broadcast to discuss the issue of global warming with an attitude completely different from the current mainstream view.The film constantly advocates that "the warming phenomenon is not caused by human activities", and interviews many climatologists, finally concluding that solar activity may be the main cause of warming.
S. Fred Singer/Dennis T. Ivoli, the author of Global Warming: An Unreasonable Panic, also chooses this position in the book, and ends with "Kyoto Protocol will end in failure".However, this book is not an authoritative work, and even uses examples against fait accompli, such as claiming that Tuvalu did not sink.
Paris Agreement
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Experts say that the Paris Agreement will come into force in 2020[6]
According to Voice of China, Beijing, November 5《Global Chinese Broadcasting Network》It is reported that yesterday, the Paris Agreement on Climate Change came into force, taking a historic step towards global climate governance after 2020.Secretary General of the United NationsBan Ki moonstayUnited Nations Headquarters, New YorkSaid: Human beings have made history in coping with climate change.[6]
Ban Ki moon said: "Today we have created the history of mankind's struggle against climate change. The landmark Paris Agreement has officially entered into force. All member countries warmly welcome the arrival of this moment, which is a day worth remembering for all people."
On April 22, 2016, the Paris Agreement was officially signed by 175 countries.According to the data provided by France, the presidency of the Paris Climate Conference, 92 parties had ratified the Paris Agreement by November 1, accounting for 65.82% of the global total greenhouse gas emissions, which crossed the two thresholds required for the agreement to enter into force.
A review of the Paris Agreement shows that the following figures and goals are the most critical: 2 degrees Celsius, a major goal set by the Paris Agreement, is to control the average global temperature rise within 2 degrees Celsius before the industrial revolution and strive to control it at 1.5 degrees Celsius.
Net zero emissions - The Paris Agreement mentioned that to reach the peak of global greenhouse gas emissions as soon as possible, the most important thing is to let the world achieve net zero emissions of greenhouse gases by the second half of this century.
40 billion tons - The Paris Agreement mentioned that the global greenhouse gas emissions will fall to 40 billion tons in 2030, which is 10 billion tons lower than the global greenhouse gas emissions of 50 billion tons in 2010. This is a big challenge.
Review every five years - from 2023, review the overall global actions every five years to encourage countries to strengthen their own actions, strengthen international cooperation and achieve the long-term goal of global response to climate change.At the same time, the Paris Agreement also insists on common but differentiated responsibilities, that is, developed countries should take more responsibility to help developing countries mitigate and adapt to climate change.[6]
On November 4, President Xi Jinping sent a letter to UN Secretary General Ban Ki moon congratulating the Paris Agreement on climate change on its official entry into force.
Xi Jinping pointed out that with the joint efforts of all parties, the Paris Agreement officially entered into force on November 4, becoming one of the fastest ratified international treaties in history.China sincerely congratulates on this.
Xi Jinping stressed that since the Paris Agreement was reached in December 2015, the international community has been committed to promoting its entry into force as soon as possible.China signed the Paris Agreement on April 22 this year, the first day of its opening for signature, and ratified it on September 3.As the presidency, China has promoted the G20 to issue a presidential statement on climate change for the first time, providing political support for the signing of the Paris Agreement.
Xi Jinping stressed that the Paris Agreement has opened a new stage of global cooperation in tackling climate change.China adheres to the concept of innovative, coordinated, green, open and shared development, will vigorously promote green and low-carbon circular development, and take strong action to address climate change.China is full of confidence in the next stage of global climate governance process and is willing to strengthen communication and cooperation with all parties to make contributions to building a win-win, fair and reasonable global climate governance mechanism.
At present, the Paris Agreement has officially entered into force, but some countries have not yet completed their domestic ratification procedures.Zou Ji, deputy director of the National Center for Strategic Research and International Cooperation on Climate Change, pointed out that the effect of the core content of the agreement will not begin to emerge until 2020.One of the most direct impacts of the entry into force of the Paris Agreement is to give policy makers, relevant stakeholders, especially some investors a stable expectation. After 2020, the direction and objectives of the policy should be determined, so that some medium - and long-term investors can arrange their own investment direction, investment fields and investment hotspots according to the policy expectations.In addition, it will also promote some other countries that have not yet ratified the Paris Agreement.
From November 7 to 18, the 22nd Conference of the Parties to the United Nations Framework Convention on Climate Change will be held in Marrakech, along with the 12th Conference of the Parties to the Kyoto Protocol and the first Conference of the Parties to the Paris Agreement.
Zou Ji said that during the meeting, more countries are expected to ratify the Paris Agreement in succession.One of the main goals of this meeting is to implement the commitment made by developed countries in 2010: to raise 100 billion US dollars for developing countries by 2020.The Cancun Agreement was signed in 2010. It has been more than six years now, and the progress is not satisfactory. The implementation of this conference is also expected.
At the beginning of September, during the G20 Summit held in Hangzhou, China took the lead in depositing its instrument of ratification of the Paris Agreement with UN Secretary General Ban Ki moon.Under the framework of the Paris Agreement, China has also set four emission reduction goals: first, by 2030, China's carbon dioxide emissions per unit of GDP will be 60% - 65% lower than in 2005;Second, by 2030,non-fossil fuelsThe proportion of total energy should be increased to about 20%;Third, by 2030 or so, China's carbon dioxide emissions should reach the peak, and strive to reach the peak as soon as possible;Fourth, increaseForest stockBy 2030, China's forest stock will increase by 4.5 billion cubic meters over 2005.[6]
On October 31, 2021The 16th G20 SummitWe agreed to work to keep the global average temperature rise within 1.5 degrees Celsius.[11]
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On January 12, 2023《Advances in atmospheric science》The journal recently released research results that in 2022, the global ocean temperature will hit the highest record since records began in 1958. Since 1990, the global ocean temperature has been accelerating.[12]
A paper published in Nature Climate Change on February 5, 2024 believes that the global average surface temperature may have risen by more than 1.5 ℃, and may exceed 2 ℃ at the end of this decade.This prediction is based on 300 year records of ocean temperature preserved by hard sponge bones in the Caribbean Sea.[15]
