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Friday 19 March 2010

global warming,know it fight it !

sir, i want to post something about global warming !

global warming,what is that?

Global warming is the increase in the average temperature of Earth's near-surface air and oceans since the mid-20th century and its projected continuation. Global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) between the start and the end of the 20th century. The Intergovernmental Panel on Climate Change (IPCC) concludes that most of the observed temperature increase since the middle of the 20th century was very likely caused by increasing concentrations of greenhouse gases resulting from human activity such as fossil fuel burning and deforestation.The IPCC also concludes that variations in natural phenomena such as solar radiation and volcanic eruptions had a small cooling effect after 1950. These basic conclusions have been endorsed by more than 40 scientific societies and academies of science,including all of the national academies of science of the major industrialized countries.An increase in global temperature will cause sea levels to rise and will change the amount and pattern of precipitation, probably including expansion of subtropical deserts. Warming is expected to be strongest in the Arctic and would be associated with continuing retreat of glaciers, permafrost and sea ice. Other likely effects include changes in the frequency and intensity of extreme weather events, species extinctions, and changes in agricultural yields. Warming and related changes will vary from region to region around the globe, though the nature of these regional variations is uncertain.

what makes global warming?

1.greenhouse effect

The greenhouse effect is the process by which absorption and emission of infrared radiation by gases in the atmosphere warm a planet's lower atmosphere and surface. It was discovered by Joseph Fourier in 1824 and was first investigated quantitatively by Svante Arrhenius in 1896.[24] Existence of the greenhouse effect as such is not disputed, even by those who do not agree that the recent temperature increase is attributable to human activity. The question is instead how the strength of the greenhouse effect changes when human activity increases the concentrations of greenhouse gases in the atmosphere.

2.the feedback effect

Strengthen the feedback effect causes of global warming is also influenced by various processes that generate feedback. An example is the evaporation of water. In the case of greenhouse gas warming due to increased CO2 gas-like, 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 until the achievement of an equilibrium concentration of water vapor. Greenhouse effect produced is greater than the effect of CO2 alone. (Although this feedback increases the absolute moisture content in the air, the air relative humidity is almost constant or even slightly decreased because the air becomes warmer). The effect of this feedback happen slowly because CO2 has a long age in the atmosphere.

3.Solar variation

variations in solar output have been the cause of past climate changes, but solar forcing is generally thought to be too small to account for a significant part of global warming in recent decades.Greenhouse gases and solar forcing affect temperatures in different ways. While both increased solar activity and increased greenhouse gases are expected to warm the troposphere, an increase in solar activity should warm the stratosphere while an increase in greenhouse gases should cool the stratosphere.Observations show that temperatures in the stratosphere have been cooling since 1979, when satellite measurements became available. Radiosonde (weather balloon) data from the pre-satellite era show cooling since 1958, though there is greater uncertainty in the early radiosonde record.


THE EFFECT :

1.Extreme weather :increased area will be affected by drought,tropical cyclone activity increased,tsunami
2.the climate will be unstabilized
3.increase of sea level
4.increase of temperature
5.ecological effect:the plant and animal will move to another place because the increase of temperature.Some plant will dissapear because can't survive in new temperature and climate
6.Human will be more difficult to find food
7.the sickness that caused by heat will be increased

WHAT WE CAN DO?

1.keep tree and plant,make your environment green okay ?
2.Save water,dont waste your water
3.use electrical equipment that environmentally friendly
4.keep your environment clean !
5.go outside,feel and enjoy the environment,and then keep it green !


by deppi kusuma aji
XI IPA 5 no 8

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