Is the Earth warming?
Is this warming is caused by pollution?
Will the change in climate bring violent weather, storms, floods, melting glaciers, rising sea levels, desertification of large areas etc.?
All these issues are exciting and controversial. It is logically so because we are talking about a problem with serious implications on the lives of millions of people. The scientific evidence is not entirely clear, but in 1995 the leading international body that oversees all research on this issue, the UN Intergovernmental Panel on Climate Change (IPCC) wrote in one of its reports: “The body of evidence suggests some degree of human influence on global climate.”
The Climate is Variable
Throughout the 4,600 million years of Earth history, climatic fluctuations have been very large. At some times, the weather has been warm and other cold and sometimes, we have moved sharply from one situation to another. Thus, for example:
Some periods of the Mesozoic Era (225 – 65 million years BP) have been the warmest of which we have reliable evidence. The average temperature of the Earth was about 5° C higher than today. In the relatively recent past 1.8 million years, there have been several extensive glaciations alternating with periods of warmer climate, similar to the present.
Inside a greenhouse, the temperature is higher than outside because it takes more energy coming out, by the very structure of the cabin, we use to heat. In the whole of the Earth, a similar effect is produced through similar natural heat retention due to some atmospheric gases. It is called greenhouse, however, in reality the physical action that occurs is completely different from what happens in the greenhouse plants.
The greenhouse effect makes the average surface temperature of earth is 33° C higher than it would be, if there were no greenhouse gases in the atmosphere.
What produces the Greenhouse Effect?
The greenhouse effect arises because the energy from the sun, coming from a very high body temperature, consists of high frequency waves through the atmosphere with great ease. The energy transmitted outwards from Earth, coming from a much colder body is in the form of waves of lower frequencies, and is absorbed by greenhouse gases. This retention of energy causes the temperature to become higher, but we must understand that ultimately, under normal conditions, it is equal to the amount of energy reaching the Earth.
Otherwise, the temperature of our planet would have been increasing steadily, which fortunately has not happened.
Logically, many scientists think that higher concentration of greenhouse gases will cause further increase in temperature on Earth. In 1979, scientists began to argue that a doubling in the concentration of carbon dioxide in the atmosphere would mean an average warming of the Earth’s surface between 1.5 and 4.5° C.
More recent studies suggest that warming will occur more rapidly over land than overseas. Heating also occurs with increased delay compared to the concentration of greenhouse gases. At first, colder oceans tend to absorb a large part of the additional heat delaying warming. Only when the oceans reach equilibrium level with the highest levels of carbon dioxide, it will produce the final heating.
The more recent studies indicate that in recent years there has been, in fact, an increased average temperature of the earth of a few tenths of a degree. Given the enormous complexity of factors affecting the climate, it is very difficult to know whether this temperature rise is within the natural variability (due to natural factors) or is due to increased greenhouse effect caused by human activity.
To analyze the relationship between different variables and climate change, computational models of enormous complexity are used. There are different models of this type and, although there are some differences between them, it is significant that they all predict a direct relationship between increase in average global temperature and increased concentrations of greenhouse gases.
About the author: Gaurav Jaggi is a passionate blogger, who loves to write on the different issues affecting our planet directly or indirectly. Visit his enticing blog on environment at thehowtobegreen.com.