But excessive greenhouse effects, induced by human activities such as burning of fossil fuels, emission CFCs, etc are harmful for the atmosphere. Scientists note that during the past 200 years the average global has increased about .40C to .80C (in Fahrenheit Scale about .70 to 1.40). Experts also estimate that if this rate of increase in the temperature remains uninterrupted, the average temperature is supposed to rise up to 10.4 degrees F by 2100.
The increase in the atmospheric temperature is mostly a response to a process called greenhouse effect that “is a natural phenomenon….whereby certain gasses in the atmosphere keep the earth’s temperature significantly higher than it would otherwise be, making it suitable for life” (Dispensa & Brule 87). The gasses prevent the magnified heat radiation to return to the space and preserve it as heat in the environment. Climatologists suggest that global warming is caused mainly by human activities that contribute to the increase in the green-house gas in the atmosphere. Natural causes such as “sunspots and natural variation of temperature change by the evolution of earth” (Dispensa & Brule 87) may increase the temperature of earth. Though some natural causes are found responsible for the emission of greenhouse gasses, environment also has its own process to absorb them. But the emission of these gasses caused by human activities is so excessive that natural absorption process cannot consume all of the produced gasses. In this regard, Dispensa and Brule (2003) notes, “The IPCC…uses the term climate change to refer exclusively to change in the climate brought about by human activities.” (p.87)
Studies show that the occurring of “killer heat-waves” (Houghton 188) is more frequent than ever. The August of 2003 was the hottest summer in the European continent in 500 years killing almost 27000 people. The rise in the global atmospheric temperature is