The 1990s have been a period of reflection at international level on environmental issues. What are we doing to our planet? We are increasingly aware that the Industrial Revolution has forever changed the relationship between man and nature.
There is widespread concern that maybe towards the middle or end of next century, human activities have changed the essential conditions that made possible the emergence of life on Earth.
The Convention United Nations Framework on Climate Change 1992 is part of a series of agreements through which countries around the world have come together to deal with this problem. Other treaties address issues such as marine pollution, desertification, the deterioration of the ozone layer, and the rapid extinction of plant and animal species. The Convention on Climate Change focuses on a particularly disturbing problem: we are changing the way solar energy interacts with the atmosphere and escapes from it and this may alter the global climate. Possible consequences could be an increase in the average temperature of the Earth's surface and changes in global weather patterns.
You also cannot rule out other unintended effects.
There are some problems that we face:
Earth long run must free the space the same amount of energy absorbed from the sun. Solar energy comes in the form of short-wave radiation, part of which is reflected by the Earth's surface and atmosphere. However, the majority passes directly through the atmosphere to heat the surface of the Earth. This shows again sending this energy into space as infrared radiation, long wave.
Water vapor, carbon dioxide and other "greenhouse gases" that exist naturally in the atmosphere, absorb much of the infrared radiation emitted by the Earth upward, preventing the pass energy directly from the earth's surface space. In turn, interaction processes (such as radiation, air currents, evaporation, cloud formation and rainfall ) carry that energy to the upper layers of the atmosphere and then is released into space. Fortunately, this process is very slow and indirect, because if the Earth's surface could radiate energy freely, our planet would be cold and lifeless, so desolate and barren as Mars.
By increasing the capacity of the atmosphere to absorb infrared radiation emissions greenhouse gases alter the way the weather keeps the balance between the incident and the radiated energy. Failure to register any additional change, doubling the concentration of greenhouse gases long life projected for early next century would reduce by 2 percent the proportion of energy that our planet emits into space. Energy cannot accumulate without further: the weather should be adapted in some way to get rid of that surplus, and while 2 percent may not seem like much, taking the Earth as a whole, this amounts to retain the energy content 3 million tons of oil per minute.
Scientists say we are altering the "engine" that drives energy climate system. Something has to change to mitigate the impact.
About 65 million years ago a giant asteroid collided with Earth. According to scientific estimates, the shock threw so much dust into the atmosphere that left the world in darkness for three years. Sunlight was greatly reduced, preventing the growth of many plants, temperatures dropped, the food chain broke and many species have disappeared, including the largest ever to walk the face of the Earth.
Such, at least, one dominant theory explaining the extinction of the dinosaurs, even those who were not hit directly by the asteroid, eventually succumbed.
The catastrophe of dinosaurs is just an illustration, but dramatically how climate change may encourage the development of a species or liquidate.
Another theory is that humans evolved when global temperatures and precipitation fell sharply decreased about six million years. The higher primates like apes of the Great Rift Valley in Africa used to take refuge in the trees, but as a result of this long-term climate change, forests were replaced by grasslands. The "apes" were found in a plain empty much colder and drier than the previous average and extremely vulnerable to predators.
Source: Guide to the Framework Convention elemental United Nations by the Office of Climate Change Information