GLOBAL WARMING
Global
warming is the process of increasing the average temperature of the atmosphere, oceans, and Earth's land.
Global average
temperature at Earth's surface has risen 0.74 ° C ± 0:18 (1:33 ± 0:32 ° F)
during the last hundred years. Intergovernmental Panel on Climate Change (IPCC)
concluded that, "most of the increase in global average temperatures since
the mid-20th century is most likely caused by increased concentrations of
greenhouse gases due to human activities" via the greenhouse effect. These
basic conclusions have been advanced by at least 30 scientific and academic
bodies, including the national science academies of all G8 countries. However,
there are still some scientists who disagree with some of the IPCC conclusions
are presented.
Climate models referenced by the IPCC project suggests global surface temperatures will rise 1.1 to 6.4 ° C (2.0 to 11.5 ° F) between 1990 and 2100. difference in estimates is due to the use of different scenarios of greenhouse gas emissions greenhouse gases in the future, as well as models of different climate sensitivities. While most research focuses on the period up to 2100, warming and sea level rise is expected to continue for more than a thousand years even if greenhouse gas emission levels have stabilized. This reflects the large heat capacity of the oceans.
Increasing global temperature is expected to lead to other changes such as rising sea levels, increased intensity of extreme weather phenomena, as well as changes in the amount and pattern of precipitation. Consequences of global warming is terpengaruhnya other crops, the loss of glaciers, and the extinction of various animal species.
Some of the things the scientists are still doubtful about the amount of warming expected to occur in the future, and how warming and the changes that occur will vary from one region to another. It is still political and public debate in the world about what, if any, action should be taken to reduce or reverse further warming or to adapt to the consequences that exist. Most of the governments of countries in the world have signed and ratified the Kyoto Protocol, which leads to the reduction of emissions of greenhouse gases.
Climate models referenced by the IPCC project suggests global surface temperatures will rise 1.1 to 6.4 ° C (2.0 to 11.5 ° F) between 1990 and 2100. difference in estimates is due to the use of different scenarios of greenhouse gas emissions greenhouse gases in the future, as well as models of different climate sensitivities. While most research focuses on the period up to 2100, warming and sea level rise is expected to continue for more than a thousand years even if greenhouse gas emission levels have stabilized. This reflects the large heat capacity of the oceans.
Increasing global temperature is expected to lead to other changes such as rising sea levels, increased intensity of extreme weather phenomena, as well as changes in the amount and pattern of precipitation. Consequences of global warming is terpengaruhnya other crops, the loss of glaciers, and the extinction of various animal species.
Some of the things the scientists are still doubtful about the amount of warming expected to occur in the future, and how warming and the changes that occur will vary from one region to another. It is still political and public debate in the world about what, if any, action should be taken to reduce or reverse further warming or to adapt to the consequences that exist. Most of the governments of countries in the world have signed and ratified the Kyoto Protocol, which leads to the reduction of emissions of greenhouse gases.
The greenhouse effect
All energy
sources that exist on Earth comes from the Sun. Most of the energy in the form
of short-wave radiation, including visible light. When this energy on Earth's
surface, he turned from the light into heat that warms the Earth. Earth's
surface, will absorb some heat and reflecting back the rest. Much of this heat
as long-wave infrared radiation into space. But some of the heat remains
trapped in Earth's atmosphere due to accumulated amount of greenhouse gases
such as water vapor, carbon dioxide, and methane which trap this radiation.
These gases absorb and reflect radiation emitted wave and consequently the
Earth's heat is stored in the Earth's surface. This happens over and over and
result in annual average temperature of the earth continues to increase.
Gases serve as the glass in a greenhouse. With the increasing concentration of these gases in the atmosphere, the more heat is trapped underneath.
Actually, the greenhouse effect is needed by all living things on earth, because without it, the planet will be very cold. With an average temperature of 15 ° C (59 ° F), the earth actually has more hot 33 ° C (59 ° F) with the greenhouse effect (without it the earth's temperature is only -18 ° C so that the ice would cover the entire surface of the Earth). But vice versa, due to the amount of these gases in the atmosphere has been excessive, global warming are the result.
Gases serve as the glass in a greenhouse. With the increasing concentration of these gases in the atmosphere, the more heat is trapped underneath.
Actually, the greenhouse effect is needed by all living things on earth, because without it, the planet will be very cold. With an average temperature of 15 ° C (59 ° F), the earth actually has more hot 33 ° C (59 ° F) with the greenhouse effect (without it the earth's temperature is only -18 ° C so that the ice would cover the entire surface of the Earth). But vice versa, due to the amount of these gases in the atmosphere has been excessive, global warming are the result.
Feedback
effects
The effects of global warming-causing agents is also influenced by various
feedback processes that result. An example is the evaporation of water. In the
case of warming due to increasing greenhouse gases such as CO2, warming will
initially lead to more amount of water that evaporates into the atmosphere.
Because water vapor is itself a greenhouse gas, warming will continue and
increase the amount of water vapor in the air to reach an equilibrium
concentration of water vapor. The resulting greenhouse effect is greater than
the effect of CO2 alone. (Although this feedback increases the absolute water
content in the air, relative humidity of air is almost constant or even
decreases slightly because the air becomes warmer). This feedback can only be
reversed slowly as CO2 has a long age in the atmosphere.
Feedback effects due to the influence of clouds is the object of current research. When viewed from below, clouds will reflect infrared radiation back to the surface, thereby increasing the heating effect. In contrast when viewed from above, clouds will reflect sunlight and infrared radiation to space, thereby increasing the cooling effect. Whether the net effect heating or cooling depending on some specific details such as the type and height of these clouds. These details are difficult to be represented in climate models, partly because the clouds are very small compared to the distance between the boundaries of computational climate models (about 125 to 500 km for the model used in the Fourth Report of the IPCC view). Nevertheless, cloud feedback ranks of two when compared with the water vapor feedback and is considered positive (adding heating) in all models used in the Fourth Report of the IPCC view.
Another important feedback is the loss of the ability to reflect light (albedo) of ice. When global temperatures increase, ice near the poles melts at an ever increasing. Together with the melting of the ice, land or water below will open. Both land and water has the ability to reflect light much less when compared to the ice, and consequently will absorb more solar radiation. This will increase the heating and causing even more ice melts, it becomes a continuous cycle.
Positive feedback due to release of CO2 and CH4 from the softening of frozen ground (permafrost) are other mechanisms that contribute to warming. In addition, the melting ice will also cause release of CH4 are also positive feedback.
The ability of oceans to absorb carbon will also be reduced if it warms up, this is caused by a decline in nutrient levels in the zone and limit the growth of diatoms Mesopelagic than phytoplankton is low carbon sinks.
Feedback effects due to the influence of clouds is the object of current research. When viewed from below, clouds will reflect infrared radiation back to the surface, thereby increasing the heating effect. In contrast when viewed from above, clouds will reflect sunlight and infrared radiation to space, thereby increasing the cooling effect. Whether the net effect heating or cooling depending on some specific details such as the type and height of these clouds. These details are difficult to be represented in climate models, partly because the clouds are very small compared to the distance between the boundaries of computational climate models (about 125 to 500 km for the model used in the Fourth Report of the IPCC view). Nevertheless, cloud feedback ranks of two when compared with the water vapor feedback and is considered positive (adding heating) in all models used in the Fourth Report of the IPCC view.
Another important feedback is the loss of the ability to reflect light (albedo) of ice. When global temperatures increase, ice near the poles melts at an ever increasing. Together with the melting of the ice, land or water below will open. Both land and water has the ability to reflect light much less when compared to the ice, and consequently will absorb more solar radiation. This will increase the heating and causing even more ice melts, it becomes a continuous cycle.
Positive feedback due to release of CO2 and CH4 from the softening of frozen ground (permafrost) are other mechanisms that contribute to warming. In addition, the melting ice will also cause release of CH4 are also positive feedback.
The ability of oceans to absorb carbon will also be reduced if it warms up, this is caused by a decline in nutrient levels in the zone and limit the growth of diatoms Mesopelagic than phytoplankton is low carbon sinks.
variation
of the Sun
Solar
variability during the last 30 years.
There is a
hypothesis which states that the variation of the Sun, with a possibility
reinforced by feedback from the clouds, can contribute to warming.The
difference between this mechanism with a warming due to greenhouse effect is
the increased activity of the Sun would heat the stratosphere reverse the
greenhouse effect will cool the stratosphere. Cooling the lower stratosphere
has been observed since at least 1960, are not going to happen when solar
activity became a major contributor to recent warming. (Depletion of the ozone
layer may also provide the cooling effect, but depletion occurred from late
1970's.) The phenomenon of solar variability combined with volcanic activity
may have provided the warming effect from pre-industrial times to 1950, as well
as a cooling effect since 1950 .
There is some research that states that the contribution of the Sun may have been overlooked in global warming. Two researchers from Duke University estimated that the Sun may have contributed to 45-50% increase in average global temperature over the period 1900-2000, and about 25-35% between 1980 and 2000.Stott and colleagues suggests that the climate model the current guidelines used to estimate the effects of excessive greenhouse gases compared with the influence of the sun, they also suggest that the cooling effects of volcanic dust and sulfate aerosols have also been underestimated.Nevertheless, they concluded that even with increased sensitivity influence of climate on the Sun though, most of the warming that has occurred in recent decades is caused by greenhouse gases.
In 2006, a team of scientists from the United States, Germany and Switzerland stated that they did not find any increase in the level of "explanation" of the Sun in a thousand years. Solar cycle only a small increase of 0.07% in the "statement" for 30 years. This effect is too small to contribute to global warming.A study by Lockwood and Fröhlich found no relation between global warming and solar variability since 1985, both through the variation of solar output or variations in cosmic rays.
Measuring global warming
There is some research that states that the contribution of the Sun may have been overlooked in global warming. Two researchers from Duke University estimated that the Sun may have contributed to 45-50% increase in average global temperature over the period 1900-2000, and about 25-35% between 1980 and 2000.Stott and colleagues suggests that the climate model the current guidelines used to estimate the effects of excessive greenhouse gases compared with the influence of the sun, they also suggest that the cooling effects of volcanic dust and sulfate aerosols have also been underestimated.Nevertheless, they concluded that even with increased sensitivity influence of climate on the Sun though, most of the warming that has occurred in recent decades is caused by greenhouse gases.
In 2006, a team of scientists from the United States, Germany and Switzerland stated that they did not find any increase in the level of "explanation" of the Sun in a thousand years. Solar cycle only a small increase of 0.07% in the "statement" for 30 years. This effect is too small to contribute to global warming.A study by Lockwood and Fröhlich found no relation between global warming and solar variability since 1985, both through the variation of solar output or variations in cosmic rays.
Measuring global warming
The
impact of global warming
Scientists use
computer models of temperature, precipitation patterns and atmospheric
circulation to study global warming. Based on these models, scientists have
made some forecasts about the impact of global warming on weather, sea levels,
coastal, agricultural, wildlife and human health.
Weather
Scientists
predict that during global warming, the northern part of the Northern
Hemisphere (Northern Hemisphere) will heat up more than other regions on Earth.
Consequently, the icebergs will melt and the land will shrink. Will be less ice
will float on northern oceans. Areas that previously experienced mild snow,
probably will not experience it again. In the mountains in temperate regions,
the snow-covered will be less and will melt faster. Growing season will be
longer in some areas. Temperatures in winter and at night would tend to
increase.
Warmer regions will become more humid as more water evaporates from the ocean. Scientists are not quite sure whether the humidity will actually increase or decrease the warming even further. This is because water vapor is a greenhouse gas, so its presence will increase the insulation effect on the atmosphere. However, more water vapor will also form more clouds, so it would reflect sunlight back into space, where it will reduce the heating process (see the water cycle). High humidity will increase rainfall, on average, about 1 percent for every degree Fahrenheit of warming. (Rainfall in the world has increased by 1 percent in the last hundred years) [21]. Storms will become more frequent. In addition, the water will evaporate more quickly from the ground. As a result, some areas will become drier than before. The winds blow harder and perhaps with a different pattern. Typhoon (hurricane) which draws its strength from the evaporation of water, will become larger. Contrary to the warming that occurred, some very cold periods may occur. Weather patterns become more extreme and unpredictable.
Warmer regions will become more humid as more water evaporates from the ocean. Scientists are not quite sure whether the humidity will actually increase or decrease the warming even further. This is because water vapor is a greenhouse gas, so its presence will increase the insulation effect on the atmosphere. However, more water vapor will also form more clouds, so it would reflect sunlight back into space, where it will reduce the heating process (see the water cycle). High humidity will increase rainfall, on average, about 1 percent for every degree Fahrenheit of warming. (Rainfall in the world has increased by 1 percent in the last hundred years) [21]. Storms will become more frequent. In addition, the water will evaporate more quickly from the ground. As a result, some areas will become drier than before. The winds blow harder and perhaps with a different pattern. Typhoon (hurricane) which draws its strength from the evaporation of water, will become larger. Contrary to the warming that occurred, some very cold periods may occur. Weather patterns become more extreme and unpredictable.
Sea
level
Changes in
average height is measured from sea level to the area geologically stable
environment.
As the atmosphere warms, the surface layer of the oceans will also warm, so the volume will expand and raise the sea level. Warming will also melt much glacier ice, especially around Greenland, which further increase the volume of water in the ocean. Sea levels worldwide rose 10-25 cm (4-10 inches) during the 20th century, and IPCC scientists predict a further rise of 9-88 cm (4-35 inches) in the 21st century.
Changes in sea levels will profoundly affect the lives in coastal areas. Increase of 100 cm (40 inches) would submerge 6 percent of the Netherlands, 17.5 percent of the Bangladesh, and many islands. Erosion of cliffs, beaches and dunes will increase. When the high seas reach estuaries, tidal flooding due to increase in the mainland. Rich countries will spend huge funds to protect coastal areas, while poor countries may only be able to evacuate from coastal areas.
Even a small rise in sea levels will profoundly affect coastal ecosystems. Increase of 50 cm (20 inches) would submerge half of coastal marshes in the United States. New marshes will also be formed, but not in urban areas and areas that have been built. This sea level rise will cover much of the Florida Everglades.
As the atmosphere warms, the surface layer of the oceans will also warm, so the volume will expand and raise the sea level. Warming will also melt much glacier ice, especially around Greenland, which further increase the volume of water in the ocean. Sea levels worldwide rose 10-25 cm (4-10 inches) during the 20th century, and IPCC scientists predict a further rise of 9-88 cm (4-35 inches) in the 21st century.
Changes in sea levels will profoundly affect the lives in coastal areas. Increase of 100 cm (40 inches) would submerge 6 percent of the Netherlands, 17.5 percent of the Bangladesh, and many islands. Erosion of cliffs, beaches and dunes will increase. When the high seas reach estuaries, tidal flooding due to increase in the mainland. Rich countries will spend huge funds to protect coastal areas, while poor countries may only be able to evacuate from coastal areas.
Even a small rise in sea levels will profoundly affect coastal ecosystems. Increase of 50 cm (20 inches) would submerge half of coastal marshes in the United States. New marshes will also be formed, but not in urban areas and areas that have been built. This sea level rise will cover much of the Florida Everglades.
Agriculture
One might
assume that a warmer Earth will produce more food than ever before, but it is
actually not the same in several places. Southern parts of Canada, for example,
may benefit from the higher rainfall and better growing season length. On the
other hand, the semiarid tropical farmlands in some parts of Africa may not be
able to grow. Desert farm regions that use irrigation water from distant
mountains may suffer if the snowpack (snow collection) winter, which serves as
a natural reservoir, would melt before the peak growing season months. Crop and
forest insect and can experience a more severe disease.
Animals and
plants
Animals and
plants are living things that are difficult to avoid the effects of warming
because most of the land has been controlled by humans. In global warming,
animals tend to migrate toward the poles and up mountains. Plants will change
the direction of growth, looking for new areas as old habitats grow too warm.
However, human development will impede this movement. Species migrate north or
south is blocked by the cities or agricultural lands may be dead. Several types
of species that are not able to rapidly move toward the poles may also be
destroyed.
human
health
Changes in
weather and ocean can lead to the emergence of diseases associated with heat
(heat stroke) and death. Hot temperatures can also lead to crop failures that
would arise from hunger and malnutrition. Changes in extreme weather and rising
sea levels due to melting Arctic ice cap could lead to diseases associated with
natural disasters (floods, hurricanes and fires) and deaths due to trauma.
Incidence of natural disasters are usually accompanied by the displacement of
people into refugee camps where disease often occurs, such as diarrhea,
malnutrition, micronutrient deficiencies, psychological trauma, skin diseases,
and others.
Shift in the ecosystem can have an impact on the spread of waterborne diseases (Waterborne diseases) and the spread of vector-borne diseases (vector-borne diseases). Such as the increasing incidence of dengue fever since the advent of space (ecosystem) new breed mosquitoes.
Environmental degradation caused by sewage pollution in the river also contributes to waterborne diseases and vector-borne disease. Coupled with air pollution emissions of these gases are not controlled factory will further contribute to respiratory diseases like asthma, allergies, coccidiodomycosis, chronic heart and lung disease, and others.
Shift in the ecosystem can have an impact on the spread of waterborne diseases (Waterborne diseases) and the spread of vector-borne diseases (vector-borne diseases). Such as the increasing incidence of dengue fever since the advent of space (ecosystem) new breed mosquitoes.
Environmental degradation caused by sewage pollution in the river also contributes to waterborne diseases and vector-borne disease. Coupled with air pollution emissions of these gases are not controlled factory will further contribute to respiratory diseases like asthma, allergies, coccidiodomycosis, chronic heart and lung disease, and others.
Control global warming
Total
consumption of fossil fuels in the world increased by 1 percent per year. Steps
taken or are being discussed at this time no one can prevent global warming in
the future. The current challenge is to overcome the effects that arise while
taking steps to prevent the changing climate in the future.
Severe damage can be overcome in various ways. Coastal areas can be protected by walls and barriers to prevent entry of sea water. Alternatively, the government can help the population in coastal areas to move to higher ground. Some countries, such as the United States, can save plants and animals while maintaining the corridor (line) habitat, clear the land that has not been built from south to north. Species can move slowly along the corridor is to go to a cooler habitat.
There are two main approaches to slow the increase in greenhouse gases. First, it prevents the carbon dioxide released into the atmosphere by storing gas or its carbon component somewhere else. This is called carbon sequestration (removing carbon). Second, to reduce greenhouse gas production.
Severe damage can be overcome in various ways. Coastal areas can be protected by walls and barriers to prevent entry of sea water. Alternatively, the government can help the population in coastal areas to move to higher ground. Some countries, such as the United States, can save plants and animals while maintaining the corridor (line) habitat, clear the land that has not been built from south to north. Species can move slowly along the corridor is to go to a cooler habitat.
There are two main approaches to slow the increase in greenhouse gases. First, it prevents the carbon dioxide released into the atmosphere by storing gas or its carbon component somewhere else. This is called carbon sequestration (removing carbon). Second, to reduce greenhouse gas production.
remove carbon
The
easiest way to remove carbon dioxide in the air is to maintain trees and plant
more trees. Trees, especially the young and rapidly growing, absorb very much
carbon dioxide, break through photosynthesis and store carbon in wood. Around
the world, the rate of forest encroachment has reached an alarming level. In
many areas, plants that grow back very little because the soil loses its
fertility when it is converted to other uses, such as for agricultural or
residential development. Measures to combat this is with the role of
reforestation in reducing the increasing greenhouse gases.
Carbon dioxide gas can also be removed immediately. You do this by injecting (injecting) the gas into oil wells to push the oil out to the surface (see Enhanced Oil Recovery). Injection can also be made to isolate it in underground gas as in oil wells, coal seams or aquifers. This has been done in one of Norway's offshore drilling rig, in which carbon dioxide is brought to the surface with natural gas is captured and injected back into the aquifer so it can not go back to the surface.
One source of supply of carbon dioxide is the burning of fossil fuels. The use of fossil fuels began to increase rapidly since the industrial revolution in the 18th century. At that time, coal became the dominant energy source for later replaced by oil in the mid-19th century. In the 20th century, began regular gas energy used worldwide as an energy source. Change of trend in the use of fossil fuels is actually indirectly have reduced the amount of carbon dioxide released into the air, because the gas releases less carbon dioxide compared to oil especially when compared with coal. However, the use of renewable energy and nuclear energy further reduces the release of carbon dioxide into the air. Nuclear energy, although controversial for reasons of safety and hazardous wastes, not even releasing carbon dioxide at all.
Carbon dioxide gas can also be removed immediately. You do this by injecting (injecting) the gas into oil wells to push the oil out to the surface (see Enhanced Oil Recovery). Injection can also be made to isolate it in underground gas as in oil wells, coal seams or aquifers. This has been done in one of Norway's offshore drilling rig, in which carbon dioxide is brought to the surface with natural gas is captured and injected back into the aquifer so it can not go back to the surface.
One source of supply of carbon dioxide is the burning of fossil fuels. The use of fossil fuels began to increase rapidly since the industrial revolution in the 18th century. At that time, coal became the dominant energy source for later replaced by oil in the mid-19th century. In the 20th century, began regular gas energy used worldwide as an energy source. Change of trend in the use of fossil fuels is actually indirectly have reduced the amount of carbon dioxide released into the air, because the gas releases less carbon dioxide compared to oil especially when compared with coal. However, the use of renewable energy and nuclear energy further reduces the release of carbon dioxide into the air. Nuclear energy, although controversial for reasons of safety and hazardous wastes, not even releasing carbon dioxide at all.
