It is estimated that the earth's temperature will rise by one to four degrees Celsius in the next 50 years. How this rise will cause the polar ice caps to melt is at the moment open to some debate. According to the World Wildlife Fund, it will mean sea levels will rise by more than one metre. And that will mean the end of many of the world's great cities, from Shanghai to Cairo, Bangkok to Venice. Possibly more tragic will be the disappearance of many of the world's low-lying deltas, areas that are used to grow much of the world's grain, wheat and rice - the land that feeds the world.
For the past 50 years, the world's population has grown by two per cent a year, increasing from 2.5 billion in 1950 to six billion by 2000. Growth rates have slowed but, according to World Resources Institute estimates and taking into account such considerations as epidemics and famines, the earth's population will swell to something like 9.5 billion by 2050. Sub-Saharan Africa will experience the biggest growth and will grow three times to about 1,750 million people. Whatever the actual growth is, in 50 years the world will be a very crowded - and hungry - place.
According to a recent World Wildlife Fund report, we have destroyed a third of the planet's natural resources in the past 25 years. Since 1970, the world's forests, fresh-water resources and marine ecosystems have all declined by 30 per cent. In the same period, human consumption of these resources has doubled and continues to rise.
According to Cornell University scientists, pollution is responsible for 40 per cent of deaths worldwide, and rising. The researchers believe increased temperatures caused by global warming will lead to an increase in human disease and the emergence of new illnesses. As the old, over-crowded urban societies become disease-ridden, millions will become 'environmental refugees', forced to abandon their homes in a desperate search for food.
The number of vehicles on China's roads has increased dramatically during the past two decades. Since 1980, the annual growth rate has been about 13 per cent. In 1998, China had about 11 million vehicles. If this growth continues, that figure will be 12.43 million by the end of 2000, 23 million by the end of 2004,42 million by 2009, 77.7 million by 2014, and 143 million by 2019.
Of the 27 billion tonnes of industrial waste water discharged annually in China, less than 30 per cent is treated and only 50 per cent of this 'treated' water meets national effluent standards. Red tides occurred once or twice a year in southern China during the 1980s: in the '90s, there have been 30 to 50 a year. Drinking water is another problem. Available fresh-water resources in China are only 24,000 tonnes per capita per year, one quarter of the world average.