Thursday, March 16, 2006

Global Warming


What's The Story?
Even the right wing press, normally so quick to diminish the credibility of any ‘green’ issue, gave their front pages over to global warming in the wake of the recent storms and floods in England. The History Channel charts the progress of this problem over the last 100 years. The storms engulfing large swathes of England have dramatically revived the increasingly ominous global warming debate. Today there is no escaping the facts: the vast majority of the country’s, indeed the world’s scientists (so rarely in accord over any issue) agree that the temperature of the earth has been rising for at least a century. “Global warming” is the basic term used to describe this effect. Confusingly, though, the cause of this warming is something that scientists do not agree on. Believers of the greenhouse effect offer the following explanation: heat from the sun enters the Earth’s atmosphere, and is trapped by gases including carbon dioxide, methane, nitrous oxide and water vapour. The sun’s heat is absorbed by these gases, preventing them from escaping our atmosphere, as they normally would. Simultaneously, there is an increase in the global average temperature. The most threatening of the greenhouses gases is carbon dioxide, because it is the most abundant, and also takes an extremely long time to break down. But omissions of all of them have been accumulating since the industrial revolution, owing to human practices: the coal, gas and oil industries, the razing of forests, numerous agricultural practices and a myriad of other disturbances. At the moment, the rate of carbon emissions is so high that the world’s plants and marine matter are unable to absorb all of it. Concurrently, there is an increase in world temperature. And more and more of the groups and organisations that were initially sceptical, are being swayed towards to the notion that these two occurrences are related. But still as vociferous are the arguments of the greenhouse effect detractors, who point out that from about 800 AD to 1200 AD, the earth's average climate was warmer than it is today - exactly one degree C warmer. Adding to this argument, the point out that there is no evidence of great flooding during this period, or of continents being submerged in water. More persuasive still is the suggestion by some scientists that this period of time is considered a “climactic optimum” – in other words, a fruitful, wonderful moment in the world’s ecology, and not a disaster at all. Global warming is an extremely broad term, however – and the idea that all we’re facing is hotter weather is considered self-deluding. Amongst the possible effects of global warming are an increase in the severity of droughts, extremes of weather, an increase in crop damage by insects, and too high a temperature for many crops to grow in the first place. Furthermore – and this we were given a foretaste of during the floods – vast tracts of land could disappear under water, and mountainous areas effectively lose entire ecosystems. Voices on either side of the argument have been getting steadily louder for over a hundred years, but those of the greenhouse effect theory have arguably been becoming more and more plausible, and harder to shrug off. Droughts and famine in India, starting in 1835 and lasting for four years, led to the very first connections established between environmental damage (in this case deforestation), and change in climate. In 1896, a chemist from Sweden proposed the theory that carbon dioxide emissions resulting from the burning of coal might enhance the greenhouse effect, and cause long-term global warming. However, 20th century thinking on the matter has been far more confusing and disparate. In 1925 an American physicist, Lotka, estimated that industry would cause carbon dioxide in the atmosphere to double in the space of 500 years. A few years after this, however, the public was told to relax – the solution had been found. This ‘solution’ was the invention of chlorofluorocarbons, which were promoted as a panacea to the problem – cheap, non-flammable, and not in any way harmful to the environment. All the worry could be forgotten. The world was completely invincible once again, thanks to these marvellous creations. By the 1940s, however, reports emerged that between 1850 and 1940 amounts of carbon dioxide in the atmosphere had risen by around ten per cent. There was a single voice of warming - one British scientist linked this increase to the warming in parts of northern Europe and North America that had been observed since the 1880s.

0 Comments:

Post a Comment

<< Home