“Our study shows that only tropical rainforests are beneficial, which helps slow down global warming,” said team leader Govindasamy Bala of Lawrence Livermore National Laboratory in California.

Forests affects our climate in many different ways: by absorbing carbon dioxide (the main gas of greenhouse effect) to help cooling down the planet, water evaporation, cloud formation, that helps preserving the planet cooler and the absorption of sunlight with their dark leaves, which is warming the Earth.

Trees that grow in snow covered places like Canada, Scandinavia and Siberia absorb sunlight that would otherwise be reflected back into space, bright white snow.

But tropical rainforests trap larger quantities of carbon dioxide and evaporate more water to produce clouds that reflect sunlight back into space.

“Tropical forests are like Earth’s air conditioning,” said Ken Caldeira of the Carnegie Institution of Washington, Bala, comrades.

Simulating the effects of deforestation in different parts of the world, including the study which was published on Apr 9 online edition of Proceedings of the National Academy of Sciences, found that deforestation, which tropics is more devastating to the Earth’s climate than deforestation in higher latitudes, and trees among high latitudes might lead to warming.

But do not take ths facts like this is the time when you should take an axe and chop down all the trees that are not growing in tropics, scientists warn.

“The main reason why it aims to slow global warming, to protect nature,” said Caldeira. “It simply makes no sense to destroy natural ecosystems name of saving natural ecosystems.”

The amount of solar radiation absorbed on Earth is only a small fraction of the total solar radiation into the atmosphere. Sun value per 100 units incident, about 30 units found in the room by one of the clouds, air, deliberation or regions on earth. This capacity for reflection, the albedo of the planet Earth, and it should not be set in the time since the magnitude and spatial distribution of the training of considerations, such as clouds and ice, may change. The 70 units of the sun’s rays, which are not reflected May be absorbed through the air, the clouds or the surface. In the absence of other complications to the thermodynamic equilibrium of the earth’s surface and the atmosphere must radiate these 70 locations in space. Soil temperature at the surface (and the lower layer of the atmosphere, especially in contact with the surface) is the size of the emission of radiation from the law by Stefan-Boltzmann.

Land of the energy budget is by greenhouse gases. Traces of gases with certain chemical properties of the so-called greenhouse gases, especially carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)-absorb a portion of the infrared radiation by the Earth’s surface. Because of this recording, a fraction of the original 70 employees not directly to the escape. Because greenhouse gases exactly the same amount of radiation they absorb and also because this radiation is spent in all directions (which, as far down as shown above), the net effect of absorption by greenhouse gases is an increase in the total amount of radiation emitted down on the earth’s surface and lower atmosphere. To maintain the equilibrium of the earth’s surface and lower atmosphere emits more radiation than the 70 employees. Therefore, the temperature must be higher. This process is not quite the same as in a real, the greenhouse effect, but the effect is similar to an end. The presence of greenhouse gases in the atmosphere leads to a warming of the surface and lower atmosphere (and cooling earlier in the atmosphere) in comparison to what was expected in the absence of greenhouse gas.

It is important to distinguish between “natural” or background, the greenhouse gases of “enhanced” greenhouse effect associated with the activities of humans. The natural greenhouse effect is with the properties of the surface of natural warming of the atmosphere of the earth, particularly the water vapor, carbon dioxide and methane. The existence of this effect is by all scientists. In fact, in his absence, the mean temperature of the earth from about 33 ° C (59 degrees F) cooler than today, and the earth would be frozen and probably planet uninhabitable. What was controversial is the so-called greenhouse effect, with an increase in the concentration of greenhouse gases from human activities. Especially by the burning of fossil fuels increases the concentration of main greenhouse gases in the atmosphere, and these higher concentrations have the potential heat up the atmosphere by several degrees.

Global warming has been caused and is due to a number of different factors. Global warming is essentially a change in climatic conditions on the ground. These weather conditions are different due to various reasons, external and internal. Changes in weather patterns, and hence global warming may lead to natural disasters or man-made conditions too. Some of the factors that cause global warming emissions are volcanic and solar activity.

According to the theory of solar variation, on Sunday is gaining strength and is the strongest in six decades. Therefore, May is already in operation, which causes global warming. Sunspots also said that one reason or catalyst for global warming. Recent studies suggest that the number of sunspots, which affects directly the next time the earth starts to cool. Sunday is the main source of energy in the field. The land consumes about seventy percent of the earth to the sun flow. This solar flux increases the temperature of the Earth’s atmosphere, land and oceans.

Orbital forcing has also said it is one of natural causes global warming. The reports show the effects slowly tilt of the Earth’s axis on the weather, which earth.The greenhouse effect, said it was a vital factor in global warming. When the infrared radiation of the Earth’s atmosphere increases the temperature of the surface is called the greenhouse effect. The greenhouse effect has grown in soil temperatures of around twenty-four per cent.

Carbon dioxide contributes to about twelve percent of the greenhouse gases, but water vapor contributes to thirty-six percent of greenhouse gases. Methane causes five to ten per cent of global warming, the ozone for about three to seven per cent of greenhouse gases can.

Solar variation, said that this was another cause global warming. Changes in the amount of radiant energy emitted by the sun known as solar variation. This solar variation is associated with changes in the Earth’s climate and temperature.

Along with natural causes global warming, scientists have also contributed to the rapid industrialization of the increase in global warming is influenced by the first today.Humans was the warming of the Earth eight thousand years, from agricultural activities. Due to the fact that the felling of forests for agriculture, the amount of carbon dioxide in the atmosphere has increased considerably.

Scientists believe that the industrialization of the press various gases such as carbon dioxide and methane, that are known to contribute to global warming. Deforestation is also said to improve global warming. The trees are of high carbon and thus are reducing the growth of carbon into the atmosphere. Humanity is also contributing to the increase of carbon dioxide from burning fossil fuels. Contribution to humanity and global warming due to burning of fossil fuels has increased by about eighty per cent in the past two years.

If the greenhouse effect exists, the temperature of the earth would be about twenty-seven degrees Celsius less. Some scientists believe that human life would be impossible for the planet Earth, where temperatures are lower.

If the greenhouse effect did not exist, the temperature of the earth would be about twenty-seven degrees Celsius less. Some scientists are of the view that human life would be impossible on Earth if the temperature would be much less.

Man-made Causes

Pollution is one of the biggest man-made problems. Burning fossil fuels is one thing that causes pollution. Fossil fuels are fuels made of organic matter such as coal, or oil. When fossil fuels are burned they give off a green house gas called CO2. Also mining coal and oil allows methane to escape. Methane is naturally in the ground. When you dig up the fossil fuels you dig up the methane as well.

Another major man-made cause of Global Warming is population. More people means more food, and more methods of transportation, right? Now your probably thinking, “Wait a minute, you said agriculture is going to be damaged by Global Warming, but now you’re saying agriculture is going to help cause Global Warming?” You’re smelling methane. Another source of methane is manure. Because more food is needed we have to raise food. More people means more cars, and more cars means more pollution. Global Warming is caused by many things. While many greenhouse gases occur naturally and are needed to create the greenhouse effect that keeps the Earth warm enough to support life, human use of fossil fuels is the main source of excess greenhouse gases. By driving cars, using electricity from coal-fired power plants, or heating our homes with oil or natural gas, we release carbon dioxide and other heat-trapping gases into the atmosphere. Deforestation is another significant source of greenhouse gases, because fewer trees means less carbon dioxide conversion to oxygen.

During the 150 years of the industrial age, the atmospheric concentration of carbon dioxide has increased by 31 percent. This increase in trapped heat changes the climate and alters weather patterns, which may hasten species extinction, influence the length of seasons, cause coastal flooding, and lead to more frequent and severe storms.

Natural Causes

Natural causes are causes created by nature. One natural cause is a release of methane gas from arctic tundra and wetlands. Methane is a greenhouse gas. A greenhouse gas is a gas that traps heat in the earth’s atmosphere. Another natural cause is that the earth goes through a cycle of climate change.

The global average air temperature near the Earth’s surface rose 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the last 100 years. The Intergovernmental Panel on Climate Change (IPCC) concludes, “most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations via the greenhouse effect. Natural phenomena such as solar variation combined with volcanoes probably had a small warming effect from pre-industrial times to 1950 and a small cooling effect from 1950 onward. The range of values results from the use of differing scenarios of future greenhouse gas emissions as well as models with differing climate sensitivity. An increase in global temperatures is expected to cause the sea level to rise, increase the intensity of extreme weather events, and change the amount and pattern of precipitation. Other effects of global warming include changes in agricultural yields, glacier retreat, species extinctions and increases in the ranges of disease vectors.

Most national governments have signed and ratified the Kyoto Protocol, aimed at reducing greenhouse gas emissions.

The term “global warming” is a specific example of the broader term climate change, which can also refer to global cooling. The United Nations Framework Convention on Climate Change (UNFCCC) uses the term “climate change” for human-caused change, and “climate variability” for other changes.

Earth’s climate changes in response to external forcing, including variations in its orbit around the sun (orbital forcing), volcanic eruptions, and atmospheric greenhouse gas concentrations. The detailed causes of the recent warming remain an active field of research, but the scientific consensus identifies elevated levels of greenhouse gases due to human activity as the main influence. In contrast to the scientific consensus that recent warming is mainly attributable to elevated levels of greenhouse gases, other hypotheses have been suggested to explain the observed increase in mean global temperature. Climate commitment studies indicate that even if greenhouse gases were stabilized at 2000 levels, a further warming of about 0.5 °C (0.9 °F) would still occur.

Greenhouse process is the process by which absorption and emission of infrared radiation by atmospheric gases warms a planet’s atmosphere and surface.

Naturally occurring greenhouse gases have a mean warming effect of about 33 °C (59 °F), without which Earth would be uninhabitable. Some other naturally occurring gases contribute very small fractions of the greenhouse effect; one of these, nitrous oxide (N₂O), is increasing in concentration owing to human activity such as agriculture. The atmospheric concentrations of CO₂ and methane have increased by 31% and 149% respectively above pre-industrial levels since 1750. Future CO₂ levels are expected to rise due to ongoing burning of fossil fuels and land-use change. Fossil fuel reserves are sufficient to reach this level and continue emissions past 2100, if coal, tar sands or methane clathrates are extensively used.