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Global Warming

Global warming is the increase in the average temperature of the earth. Because it is used in reference to an average temperature, the term can still apply even as different locations of the world may be experiencing more or less warming than others. Some locations of the planet may even experience a cooling of regional temperature as the average temperature of the world increases.

It is a well-documented fact that planet earth has experienced global warming in recent years. Since 1880, average temperatures around the world have climbed 1.4 degrees Fahrenheit, or 0.8 degrees Celsius. This is according to NASA's Goddard Institute for Space Studies.

The Institute has also estimated that the year 2005 has thus far been the warmest year since the 1800s. In other words, since reliable instrumental measurements became available and widespread. This record set in 2005 exceeded a 1998 record by a few hundredths of a degree. This means that the two warmest years have occurred in the past decade. Both the Climatic Research Unit and the World Meteorological Organization agree with these figures.

The United Nations' Intergovernmental Panel on Climate Change (IPCC) finished a Fourth Assessment Report in early 2007. As part of this report, it was determined that evidence of the occurrence of global warming was “unequivocal.” Another important conclusion declared by the panel was that the increase of temperature over the last fifty years is very likely due to the observed increase in human-caused greenhouse gas emissions. The use of the phrase “very likely” implies a likelihood of at least 90%.

Greenhouse gases and the greenhouse effect are part of a natural system of regulating the earth’s temperature. The gases allow sunlight to reach the planet while preventing heat from leaving the atmosphere. Without them, the planet would be uninhabitable.

An excess of these gases can produce an enhanced greenhouse effect. The human-induced greenhouse effect is of major concern because it can warm the planet more quickly than humankind has ever seen.

Examples of greenhouse gases include water vapors, carbon dioxide, methane, ozone and nitrous oxide. The main contributor to climate change of the greenhouse gases is carbon dioxide.

While the evidence of global warming has been deemed unequivocal, the reasoning behind it has been contested by a few scientists. This has lead to the IPCC facing some criticism. However, its position as a representative for the international scientific community’s stance on climate change as been supported by such Academies of Sciences and Royal Societies as those of Australia, Belgium, Brazil, Canada, the Caribbean, China, France, Germany, India, Indonesia, Ireland, Italy, Malaysia, New Zealand, Sweden and the United Kingdom.

Further research into the natural variability of temperature over a long period of time may be what is ultimately necessary to answer the causal disputes. It is also worth noting that just as some question the validity of the conclusions which the IPCC draws, others question the conservativeness of its estimates.

Increased rate of glacier retreat, Arctic shrinkage, and sea level rise are among the direct global warming effects as listed by the IPCC. In addition to these, there are also many predicted regional and secondary effects. The expansion of tropical diseases, changes in the seasonal patterns of ecosystems, and a rise in extreme weather events are some examples.