How do we know climate change is happening?

Physics and chemistry behind the greenhouse effect is simple. We have known for over 100 years (Joseph Fourier, beat in 1824, followed by Svante Arrhenius test in 1896).

Certain types of chemicals, called "greenhouse gases", because of the absorption and emission of infrared radiation in the atmosphere of the Earth's surface and lower atmosphere.

As this diagram show how water vapor greenhouse gas, carbon dioxide (CO2), methane (CH4) and ozone (O3) in the atmosphere due to heat is recovered and brought to the surface of the earth.

So how do we know if climate change really happening?

Guttata Clem: How do we know climate change is happening? A few months ago, the U.S. National Oceanic and Atmospheric Administration have released. "The State of the Air 2009 report," It was found that:

The scientific evidence of our planet is warming unequivocal. More than 300 scientists from 160 research groups in 48 countries have contributed to the report, which was the warmest in the last decade and that the Earth was hotter in the last 50 years, more and more confirmed.

Because of data obtained from multiple sources, the report sets out 10 measurable functions on a global scale are used to measure temperatures around the world. The relative motions of each of these indicators show compatible with global warming. Seven indicators of increased air temperature on land surface temperature of the sea, the air temperature above the sea, sea, ocean heat, humidity and temperature in the troposphere layer "active time" of the atmosphere closest to the Earth's surface. Three indicators are falling: the coverage of Arctic sea ice, glaciers and snowfields in the northern hemisphere.

Remember the first time, and to convince a single comparison, analysis of observational studies and several cases from the top of the atmosphere into the depths of the oceans, "said Jane Lubchenco, PhD, undersecretary of commerce for oceans and atmosphere and NOAA administrator.”The documents come from many institutions worldwide, using data from various sources, including satellites, weather balloons, weather stations, ships collected, buoys and field studies of these lines of evidence all the independent production points to the same conclusion: Global warming is .. "

The report stresses that human society has developed thousands of years in climatic conditions, and now a new set of conditions takes shape. These conditions are always warm, and some areas are probably the most extreme events such as droughts, torrential rains and violent storms show.