GLOBAL WARMING

Global Warming or Global Warming is the process of increasing the average temperature of the atmosphere, ocean, and the Earth's land. Global average temperature at Earth's surface has increased by 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, most likely caused by increased concentrations of greenhouse gases due to human activities" [1] via the greenhouse effect. These basic conclusions have been advanced by at least 30 scientific and academic bodies, including all the national science academies of the G8 nations. However, there are still some scientists who disagree with some of the IPCC conclusions are presented.

Climate models project that was used as reference by the IPCC shows global surface temperature will rise 1.1 to 6.4 ° C (2.0 to 11.5 ° F) between 1990 and 2100.
1. Differences guesstimate was caused by using different scenarios of greenhouse gas emissions greenhouse gases in the future, as well as models of different climate sensitivities. Although most research is focused 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 been stable. This reflects the large heat capacity of the oceans. Increasing global temperatures are expected to lead to other changes such as rising sea levels, increased intensity of extreme weather phenomena.
2. As well as changes in the number and pattern of precipitation. Consequences of global warming are another character of agricultural output, loss of glaciers, and the extinction of various animal species. Some of the things that scientists are still doubtful about the amount of warming predicted to occur in the future, and how warming and the changes that occur will vary from one region to another. Until now there 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 of the existing. Most governments of the world's countries have signed and ratified the Kyoto Protocol, which leads to a reduction in emissions of greenhouse gas.

Greenhouse effect

All sources of energy contained in the Earth comes from the sun. Most of the energy in the form of short wave radiation, including visible light. When this energy reached Earth's surface, he changed from light into heat that warms the Earth. Earth's surface, will absorb some of the heat and reflecting back the rest. Some of this heat wave form of infrared radiation into space long. But some of the heat remains trapped in the earth's atmosphere due to deposition amount of greenhouse gases such as water vapor, carbon dioxide, and methane which trap the waves of this radiation. These gases absorb and reflect back the radiation waves emitted by the Earth and consequently the heat is stored in the Earth's surface. This situation occurs continuously resulting in an annual average temperature of the earth continues to rise. These gases may serve as a greenhouse gas. With the increasing concentration of these gases in the atmosphere, the more heat is trapped underneath. The greenhouse effect is very much needed by all living things on earth, because without it, this planet will become very cold. With an average temperature of 15 ° C (59 ° F), the earth actually has more hot 33 ° C (59 ° F) from the initial temperature, if there is no greenhouse effect the earth temperature is only -18 ° C so that ice will cover the entire Earth's surface. But on the contrary, if the gases in the atmosphere has been excessive, will cause global warming.

Stock feedback

Elements that cause global warming 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 like CO2, warming will initially lead to more number of water 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. The resulting greenhouse effect is larger than the effect of CO2 alone. (Although this feedback to improve the absolute water content in the air, relative humidity is almost constant or even slightly decreased because the air becomes warmer). [3] This feedback affects only slowly because CO2 has a long age in the atmosphere.
Feedback effect due to the influence of clouds is becoming the object of current research. When viewed from below, clouds will reflect infrared radiation back to the surface, so that will increase the warming effect. In contrast when viewed from above, clouds will reflect sunlight and infrared radiation to space, thereby increasing the cooling effect. Does it produce a net effect of warming or cooling depending on some specific details such as the type and height of the cloud. The details are difficult to be represented in climate models, partly because the cloud is very small compared to the distance between the boundaries of the computational climate models (about 125 to 500 km for the model used in the IPCC Fourth Report's view). Nevertheless, cloud feedback is at number two when compared with water vapor feedback and is considered positive (adding heat) in all models used in the IPCC's view to the Fourth Report.
Another important feedback is the loss of ability to reflect light (albedo) of ice.
As global temperatures increase, ice near the poles melts with increasing speed. Simultaneously 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 with ice, and consequently will absorb more solar radiation. This would increase the warming and causing even more ice melts, becomes a continuous cycle.
Positive feedback due to release of CO2 and CH4 from the softening of frozen soil (permafrost) are other mechanisms that contribute to warming. In addition, the melting ice will also cause release of CH4 are also positive feedback.
Ability of oceans to absorb carbon will also be reduced if he warms up, this is caused by the decline in nutrient levels in the mesopelagic zone would limit the growth of phytoplankton diatoms than a carbon sink that low.

Controlling global warming

Total consumption of fossil fuels in the world increased by 1 percent per year. Steps taken or currently being discussed that no one can prevent global warming in the future. The challenge today is to overcome the effects that may arise while performing these steps to prevent further climate change 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, clearing land for construction from south to north. The species can gradually move along this corridor to go to a colder habitat.

There are two main approaches to slow down the increasing greenhouse gases. First, prevent the carbon dioxide released into the atmosphere by storing the gas or its carbon component somewhere else. This method is called carbon sequestration (removing carbon). Second, reducing greenhouse gas production.