What caused Global warming?

Since we knew the science of the climate, scientists have learned that the Earth's climate was changing. From the study of ice age in the past showed that the climate can change by itself, even radically. What causes it?

After the 19th century, the study of the climate began to learn about the gas content in the atmosphere, known as greenhouse gases, which can affect the climate on Earth is an effect called the greenhouse effect. What's that? IT is an effect, in which the molecules in our atmosphere are like a greenhouse. The greenhouse effect should be a natural effect to keep the surface temperature of Earth is at its normal temperature, about 30° C, else then there will be no life onthis earth.

In about the year of 1820, Fourier discovered that the atmosphere was easy breached (permeable) by sunlight entering the Earth's surface, but not all the light emitted by the Earth's surface can be reflected out, infra-red radiation which should be reflected was trapped, thus the Earth's atmosphere trap heat (the principle greenhouse).

Thirty years later, Tyndall found that the types of heat trapping gases are mainly carbon-dioxide and water vapor, and these molecules are eventually named as a greenhouse gas, as we know it today. Arrhenius later showed that if the concentration of carbon-dioxide doubled, the increase in surface temperature becomes very significant.

Next to the discovery of Fourier, Tyndall and Arrhenius, the more scientists understand how the greenhouse gases absorb the radiation, allowing to make a better calculation for linking greenhouse gas concentrations and increas

ed temperatures. If carbon-dioxide concentrations doubled it, then the temperature can rise to 1 ° C.

However, the atmosphere was not as simple calculation model, the reality of raising the temperature can be more than 1 ° C because of factors such as, say, a change in the number of clouds, reflecting different heat between land and ocean, changes in moisture content in the air, surface changes Earth, either because of land clearing, changes in the surface, or causes the other, because of natural or human actions. The evidence suggests, the atmosphere becomes hotter there, with the atmosphere hold more moisture, and store more heat, warming strengthening of the standard calculation.

Since 2001, studies of global climate dynamics indicate that at least, the world has experienced warming of more than 3 ° C since pre-industrial era, it can suppress it if greenhouse gas concentrations to stabilize at 430 ppm CO2e (ppm = parts per million = per million of CO2 equivalent - which states the ratio of the number of molecules of CO2 per one million air dry). To be sure, since 1900, the Earth has experienced warming of 0.7 ° C.

Then, if it happens warming, as it is called; what became known as global warming. Is a natural phenomenon that is unavoidable? Or is there some significant reason that make it 'popular' today?

International cooperation needed to be able to say that indeed humans who became the main cause of global warming. The IPCC report (Intergovernmental Panel on Climate Change) in 2007, shows that the global average since 1750 of human activity causing the warming. Changes in the abundance of greenhouse gases and aerosols due to radiation of the Sun and the Earth's surface affects the overall energy balance of the climate system. In amounts expressed as a Radiative Forcing gauge whether the global climate to heat or cold (in red states or lead to a positive value becomes warmer, and blue opposite), it was found that due to human activity is the (anthropogenic) which becomes the main driver of global warming.

The results of the approximate calculation agent driving global warming and the mechanism (column one), based on radiation effects (Radiative Forcing), in units of Watts / m ^ 2, for anthropogenic sources and other sources, marked in red and positive values of columns two and three means contribution to the warming, while blue is the opposite effect. Source: IPCC Report, 2007.

The picture shows that carbon-dioxide gas is the main contributor glass. From the pre-industrial 280 ppm for a 379 ppm in 2005. This figure exceeds the natural rate of climate change studies from the past (paleoclimatology), where over 650 thousand years is only an increase of 180-300 ppm. Especially in the last decade (1995-2005), recorded an increase of carbon-dioxide concentration of the largest annual (1.9 ppm per year), far greater than atmospheric measurements in 1960, (1.4 ppm per year), although there are variations in per - year.

Source mainly increased concentration of carbon-dioxide is the use of fossil fuels, plus the influence of land surface changes (land clearing, deforestation, forest fires, melting ice). Increasing concentrations of methane (CH4), from 715 ppb (parts per billion = one per billion) in pre-industrial to 1732 ppb in the early 1990s, and 1774 in the year 2005. This exceeds the numbers naturally change over 650 thousand years (from 320 to 790 ppb). The main source of agricultural methane and increased use of fossil fuels. Concentrations of nitrous-oxide (N2O) from 270 ppb - 319 ppb in 2005. Like other contributors to emissions, is the main source of agricultural humans. Combination three main components are the biggest contributor to global warming.
Anthropogenic contribution of aerosols (sulphate, organic carbon, black carbon, nitrate and dust) cooling effect, but the effect is still not dominant compared to the warming, in addition to the uncertainty calculations are still very large. Likewise, the ozone changes due to chemical processes troposper formation of ozone (nitrogen oxides, carbon monoxide and hydrocarbons) contribute to global warming. Ability sunlight reflectivity (Albedo), due to changes in the Earth's surface and the deposition of black carbon aerosol from the snow, resulting in changes varied, from cooling to heating. Changes from sun rays (solar irradiance) is not a big contribution to the warming global.

So, it is understood that humans do play a role for his own fate, because of global warming caused by man's own actions. For that we have responsibility to make some action to save the earth so then human and nature can live in harmony.