Global Ecological Problems and Issues

In Bangladesh about ten million people are already living like this: the poorest families have been pushed on lands that will sooner or later be swallowed by the great rivers, that are continuously changing their courses. Many families have been forced to move more than ten times, and each time they have been forced to construct new huts for themselves - which has eaten away what little money they have been able to save.

Also the areas that are lying on somewhat higher ground would be likely to suffer. Various extreme weather conditions like floods and droughts would become more common. The incidence of devastating typhoons and hurricanes might increase by a factor of ten, if the world will become five centigrade warmer than now. At the same time the destructive power of the worst storms might increase by 50 or 60 percent because of the higher temperatures - and higher wind speeds caused by them. This would be very bad news for the countries that are suffering from typhoons or hurricanes. A major hurricane or typhoon can, already now, wreck the economy of a whole country for decades. Super-hurricanes created by global warming would do still much more damage.

Besides the rise in sea levels, the most serious consequence of the global warming could be the drying of the tropical and sub-tropical areas. Even though rainfall would be likely to increase, it is likely that evaporation would increase even more. According to one estimate a four-centigrade warming in global temperatures would increase, on average, rainfall by 12 per cent and evaporation by 30 per cent in the tropical and sub-tropical areas. This would most probably cause a disastrous decline in agricultural yields, unless the emphasis will be shifted to crops that do not require much water.

According to the second IPCC report the drying of the tropics might reduce the flow of Nile by 75 per cent, which would be a catastrophe for Egypt and its neighbours. Many other large rivers in India, Pakistan and China - including the Indus - could would also suffer because of the increased evaporation rates. According to IPCC up to five billion people might be faced with acute water scarcities by the year 2025, at least partly because of the global warming.

A further threat comes from the melting of the Himalayan glaciers. The quantity of water in the Himalayan glaciers is not large enough to raise the sea level in a significant way, but the issue is extremely serious because of other reasons.

If the snow and ice masses in the Himalayas continue to melt, the water supply of much of Asia will be affected. Indus, Ganga, Mekong, Yangtze, Huangho and many other major rivers get a major part of their dry season flows from the Himalayan glaciers.

It has been predicted, that the Himalayan glacial area alone will shrink by one-fifth within the next 35 years, to 100 000 square kilometres. In the last 50 years alone some 15 000 glaciers have already vanished in the Himalayas. In the Gangotri Glacier of Indian Himalayas - the source of the holy Ganga - is now retreating with an average speed of 30 metres a year, compared with only 18 metres a year between 1935 and 1950 and only 7 metres a year between 1842 and 1935. The Pindari Glacier is now retreating at an average rate of 135 metres a year. Indian scientists have projected that by 2030 many of the rivers originating from the Himalayas, including the Ganges, Kali and Indus, to name a few, will all be dry during the dry season.

These are grave predictions, especially because the groundwater resources in South Asia, South-East Asia and China are also being depleted with a frightening speed.

Many tropical diseases that require high temperatures, would spread with the increasing temperatures. For instance, the global warming might greatly increase the number of people that are threatened by the deadliest form of malaria, Plasmodium falciparum, and by schistosomiasis. Falciparum malaria is already killing three million people, every year, and the situation is getting worse because the malaria parasites are rapidly developing strains that are resistant to most of the known medicines. At the same time the mosquitoes that spread the parasites are becoming resistant to pesticides.

Schistosomiasis already affects 250 million people, and causes permanent damage and disability for many of the carriers. Large parts of Asia, Africa and Latin America have this far been spared from the problem, because their winter temperatures have been too low for these parasites. But this could soon change because of the global warming.

According to the IPCC the world has probably already warmed by 0.6 centigrade because of the greenhouse gas emissions from the burning of fossil fuels and from the destruction of tropical forests. This might be only 50 per cent of the warming we have already committed ourselves by emitting a certain amount of carbon dioxide and other greenhouse gases into the atmosphere.

According to IPCC a certain increase in the concentration of greenhouse gases in the atmosphere will, on a longer run, warm the global climate by a certain number of centigrade. But because the oceans warm only very slowly, at a much slower pace than the atmosphere itself, there is a long delay before the whole impact has actually been realized.

In other words, even if we would eliminate all our greenhouse gas emissions, today, it is possible that the climate would still go on warming by another 0.6 centigrade.

The most frightening possibility is the so called runaway greenhouse effect. This far the oceans, soils, peat lands and forests of the Earth have absorbed a significant part of all the greenhouse gas emissions. This has slowed down the warming process. But many scientists are afraid, that if the climate warms too much, the global warming starts to feed itself.

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