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Global Warming

Global Warming is a process of increasing the average temperature of the atmosphere, ocean, and land Earth. Global average temperature at Earth's surface has increased by 0.74 ± 0.18 ° C (1.33 ± 0.32 ° F) over the last hundred years. Intergovernmental Panel on Climate Change (IPCC) concluded that, "the majority of the increase in global average temperatures since the mid-20th century, most likely caused by increased concentrations of green house gases due to human activities" through the green house effect. These basic conclusions have been put forward by at least 30 scientific and academic bodies, including all national science academies of the G8 countries. However, there are still some scientists who do not agree with some of the conclusions of the IPCC stated.

Scientific understanding of global warming is increasing. In its 2014 report the Intergovernmental Panel on Climate Change (IPCC) reported that scientists were more than 95% certain that most of global warming is caused by increasing concentrations of green house gases and other human (anthropogenic) activities. Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to 1.7 °C (0.5 to 3.1 °F) for their lowest emissions scenario using stringent mitigation and 2.6 to 4.8 °C (4.7 to 8.6 °F) for their highest. These findings have been recognized by the national science academies of the major industrialized nations.

Future climate change and associated impacts will differ from region to region around the globe. Anticipated effects include warming global temperature, rising sea levels, changing precipitation, and expansion of deserts in the subtropics. Warming is expected to be greatest in the Arctic, with the continuing retreat of glaciers, permafrost and sea ice. Other likely changes include more frequent extreme weather events including heat waves, droughts, heavy rainfall, and heavy snowfall, ocean acidification, and species extinctions due to shifting temperature regimes. Effects significant to humans include the threat to food security from decreasing crop yields and the loss of habitat from inundation.

The global average and combined land and ocean surface temperature, show a warming of 0.85 [0.65 to 1.06] °C, in the periode 1880 to 2012, based on multiple independently produced datasets. The Earth's average surface temperature rose by 0.74±0.18 °C over the periode 1906–2005. The rate of warming almost doubled for the last half of that periode (0.13±0.03 °C per decade, versus 0.07±0.02 °C per decade). The average temperature of the lower troposphere has increased between 0.13 and 0.22 °C (0.22 and 0.4 °F) per decade since 1979, according to satellite temperature measurements. Climate proxies show the temperature to have been relatively stable over the one or two thousand years before 1850, with regionally varying fluctuations such as the Medieval Warm Periode and the Little Ice Age.

Most countries are parties to the United Nations Framework Convention on Climate Change (UNFCCC), whose ultimate objective is to prevent dangerous anthropogenic climate change. The UNFCCC have adopted a range of policies designed to reduce green house gas emissions and to assist in adaptation to global warming. Parties to the UNFCCC have agreed that deep cuts in emissions are required, and that future global warming should be limited to below 2.0 °C (3.6 °F) relative to the pre-industrial level. The global average and combined land and ocean surface temperature, show a warming of 0.85 [0.65 to 1.06] °C, in the periode 1880 to 2012, based on multiple independently produced datasets.

The Earth's average surface temperature rose by 0.74±0.18 °C over the periode 1906–2005. The rate of warming almost doubled for the last half of that periode (0.13±0.03 °C per decade, versus 0.07±0.02 °C per decade). The average temperature of the lower troposphere has increased between 0.13 and 0.22 °C (0.22 and 0.4 °F) per decade since 1979, according to satellite temperature measurements. Climate proxies show the temperature to have been relatively stable over the one or two thousand years before 1850, with regionally varying fluctuations such as the Medieval Warm Periode and the Little Ice Age.

Some causes of global warming or global warming

1.      Greenhouse Effect

All energy sources that exist on Earth comes from the sun. Most of the energy is in the form of short-wave radiation, including visible light. When this energy on the Earth's surface, he turned on the light into heat that warms the Earth. Earth's surface will absorb some of the heat and reflect the rest. Some of this heat as long-wave infrared radiation into space. However, some heat remains trapped in the earth's atmosphere due to the accumulated amount of green house gases include water vapor, carbon dioxide, and methane that become traps for this radiation.

These gases absorb and reflect radiation emitted by the Earth and consequently the heat stored in the Earth's surface.  These gases functioning as the glass in a green house. With the increasing concentration of these gases in the atmosphere, the more heat is trapped below. Actually, the green house effect is very much needed by all living things on earth, because without it, the planet would be very cool so that the ice will cover the entire surface of the Earth. However, due to the amount of these gases in the atmosphere has been excessive, be a consequence of global warming.

2.      Efek Feedback

The effects of global warming-causing agents are also influenced by various feedback processes that result. An example is the evaporation of water. In the case of warming caused by greenhouse gases such as CO2, warming will initially cause greater volumes of water that evaporates into the atmosphere. Because water vapor is it self a green house gas, warming will continue and increase the amount of water vapor in the air until it reaches equilibrium with the water vapor concentration. The resulting green house effect greater than the effect of CO2 alone.

These details are difficult to represent in climate models, partly because the clouds are very small compared to the distance between the boundaries of computational climate models (around 125 to 500 km for models used in the IPCC report to Four Views. Another  important feedback is the loss of reflectance (albedo) by ice. 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 ice that melts will also release CH4 which also give rise to positive feedback. The ability of the oceans to absorb carbon will also be reduced when he warmed up, this is caused by the decline in the level of nutrients in the mesopelagic zone, limiting the growth of phytoplankton diatoms rather than a carbon sink that low.

3.      Variations of the Sun

There is a hypothesis that variations of the Sun, with the possibility reinforced by the feedback from the cloud, can contribute to warming today. The difference between this mechanisme with the warming due to the green house effect is the increased activity of the Sun would heat the stratosphere reverse the green house effect cools the stratosphere. Cooling of the lower stratosphere has been observed since at least 1960, which would not happen if the activity of the Sun became a major contributor to recent warming. The thinning of the ozone layer also can provide a cooling effect but the depletion occurs from the end of the 1970s. The phenomenon of solar variability combined with volcanic activity may have given the warming effect from pre-industrial times to 1950, as well as the cooling effect since 1950.

The impact of global warming

1.      Weather

Scientists predict that during global warming, northern regions of the northern hemisphere (Northern Hemisphere) will warm faster than other regions on Earth. As a result, ice bergs will melt and the land will shrink. There will be less ice floating in the waters of the North. Areas which previously experienced a mild snow, probably will not get it again. In the temperate mountains, snow-covered portion will shrink and will melt faster. The planting season will be longer in some areas. Temperatures in winter and at night will tend to increase.

2.      The high sea level

Changes in the average height of the sea level measured in regions with geologically stable environment. When the atmosphere warms, the surface layer of the oceans will also be warmed up, so that the volume will be enlarged and raise sea levels. Warming will also melt a lot of ice at the poles, especially around Greenland, which will raise the volume of water in the ocean. Sea levels around the world have increased by 10-25 cm (4-10 inches) during the 20th century, and scientists from the IPCC predict a further rise 9-88 cm (4-35 inches) in the 21st century. Changes in sea levels will greatly affect life in coastal areas. The increase in 100 cm (40 inches) would drown 6 percent of the Dutch area, 17.5 percent of the region of Bangladesh, and many islands. Erosion of cliffs, beaches and sand dunes will increase. When the high seas reached estuaries, tidal flooding will increase in the mainland.

3.      Agriculture

One might assume that a warm earth will produce more food than ever before, but it is actually not the same in some places. Southern parts of Canada as an example, may benefit from higher rain fall and over the length of the growing season. On the other hand, semi-arid tropical agricultural land in some parts of Africa may not be able to grow. Desert agricultural areas that use irrigation water from distant mountains may suffer if the snowpack (snow collection) winter, which serves as a natural reservoir, will melt before the peak months of planting. Food crops and forest insect and disease attack more powerful.

4.      Animals and plants

Animals and plants into living creatures that are difficult to avoid the effects of global warming because most of the land is controlled by humans. In global warming, animals tend to migrate toward the poles and up the mountains. Plants will change the direction of growth, seeking new areas as old habitats become too warm. However, human development will hinder this displacement. Species that migrate north or south that are blocked by cities or agricultural lands may be dead. Some types of species that are not able to move quickly towards the poles may also be destroyed.

5.      Human Health

The world is warmer, scientists predict that more and more people are affected by the disease or died from heat stress. Outbreaks of the disease commonly found in tropical areas, such as diseases caused by mosquitoes and other disease-carrying animals, will be more widespread because they can move into areas previously too cold for them. Currently,  45 percent of the world's population live in areas where they can be bitten by mosquitoes carrying the malaria parasite, that percentage will rise to 60 percent if temperatures rise. Other tropical diseases also can be spread like malaria, dengue fever, yellow fever, and encephalitis. Scientists also predict rising incidence of allergies and respiratory diseases due to warmer air will increase pollutants, mold spores and pollen.