Yellowstone Supervolcano
3 star(s)
Discuss the causes of Global Warming
Extracts from this document...
Introduction
Discuss the causes of Global Warming Ideally, the earth is constantly kept at an ideal temperature to sustain life of around 16?C (60?F). The earth is heated by the sun's rays in the form of visible short-wave light, the majority of these rays pass from the sun, virtually unstopped through the thermal 'blanket' of the earth's atmosphere, and heat the surface of the earth. This energy, after the earth has absorbed it, is transferred back into space as long-wave infrared energy. The 'natural greenhouse effect' is the accepted warming up of the earth that is explained by the presence of naturally occurring greenhouse gases, and has been observed on other planets (Houghton, J 1994). Global warming, however, has been and continues to be a major concern for the planet. It is the process by which the earth's surface is gradually increasing in temperature because of a variety of factors but primarily because of human activity, either by creating new sources of greenhouse gases or by obstructing natural sinks that eliminate them. ...read more.
Middle
Fig.2 shows the flows and stores of a carbon cycle and the increased levels which contribute to global warming (Gribbin 1978, McCarthy et al. 1986). Another main cause of global warming is the release of methane into the atmosphere. This accounts for 20% of the 'enhanced greenhouse effect', it comes primarily from agriculture, especially flooded rice paddies, and animal waste, both of which coincide with the increase of CO2 from deforestation as the pressure for land increases and more is cleared, so in turn the levels of greenhouse gases are heightened. It is difficult to make an accurate statement of how much this has affected global warming because the majority of this production is done in the developing world where research is limited, but the trend of increased global warming has followed that of the increase in rice cultivation (Watson et al 1990). The final of the important factors that contribute to global warming is nitrous oxides, chlorofluorocarbons (CFCs) ...read more.
Conclusion
There have been attempts to try to lower global warming especially concerning CFCs and the emissions of CO2 but it still remains a serious concern and it has been estimated that without any curb of the current trends the average temperature will rise by up to 1/4?C every 10 years or 21/2?C every century (Kemp, D 1994). Fig. 3 shows what is predicted will happen to greenhouse gas levels depending on whether we 'carry on as we are' or try to prevent it. (Houghton et al. 1990). Therefore to conclude, although the 'natural greenhouse effect' does exist it is enhanced by the considerable role human activity has to play and although predictions have been made as to what the long term results will be, such as melting of polar ice caps which will cause coastal flooding and also a significant change in climate with more frequent tropical storms (UNFCCC), it can not be certain what positive feedbacks have already occurred. ...read more.
The above preview is unformatted text
This student written piece of work is one of many that can be found in our GCSE Physical Geography section.
Found what you're looking for?
- Start learning 29% faster today
- 150,000+ documents available
- Just £6.99 a month
