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Dr John Kenner, the main character in Michael Crichton?s latest thriller State of Fear, accuses the US of creating artificial hurricanes, explosions and earthquakes in some isolated islands to substantiate the claims of climate scientists that global warming is a real phenomenon. He has also blamed climate scientists for predicting temperature data in 1988 that are 300 per cent exagerrated. The book has been heavily criticised by many, including the environmentalists who have accused him for distorting and ignoring the findings.

There is no denying the fact that our planet is getting warmer. Scientists relate this with the increase in carbon dioxide concentration in the atmosphere as also with a rise in sea level. Extensive publicity on global warming, greenhouse effects and rising sea level through different media has alarmed everyone. People wonder if this is the first time the climate is getting changed.

The Intergovernmental Panel for Climate Change (IPCC) reports in 2001 pointed out that the Maldives and many such islands and coastal areas in the Indian Ocean would disappear one day owing to sea level rise and global warming. While tides, storms, hurricanes and tsunamis cause sea level rise for short durations, complicated interaction of a large number of variables affects the coastal dynamics for a longer time. Such variables are temperature and salinity of seawater, basin volume change, tectonic instability, glaciations, changes in the obliquity of the earth?s axis, its rotational speed and thermal expansion.

Our planet took 1,000 million years to become cold enough to withhold rainwater within its tectonically-formed large basins called oceans. It took another 3,000 million years to set right the atmosphere suitable for evolving higher forms of life. During the last 1.8 million years, there were at least 30 glacial cycles on the earth. In a glacial period the earth becomes cold, the ocean water moves laterally towards higher latitudes. As the ice forms in the polar regions, the sea level falls. The earth acts as a natural thermostat; it allows the temperature to fall up to a certain level, after which it warms up and the ice melts. During cooling, the CO2 concentration in the atmosphere becomes less, and this wreaks havoc on plant life. When the temperature goes up again, the CO2 level, too, increases.

The last glacial period started 40,000 years before present (YBP) and the glacial peak reached around 18,000 YBP. A huge layer of ice developed in the polar regions during the peak of glaciations. During rebound, warmer climate prevails on the earth and that melts the ice and raises the sea level.

The atmospheric CO2 concentration during the glacial peak decreased to 190-200 ppmv (parts per million by volume). Since then it has been increasing in the last 5,000 years, and now it is 260 ppmv, according to Prof. N.A. Morner, a scientist studying sea level change at the Stockholm University, Sweden. Bioscientists, however, argue that though urbanisation has led to deforestation, the higher levels of CO2 have actually caused enhanced productivity of the cultivated areas, simply by increasing the rate of photosynthesis.

Records say that in the past 100 years global temperature has gone up by 0.6 to 0.70 C, and the sea level by 10 to 25 cm. The IPCC reports an average of 0.32 mm rise in the sea level per year during the last decade. It predicts a 60 C rise of global temperature by the end of this century, which, along with other processes like ocean warming, may raise the sea level by more than 50 cms.

In his keynote address at the International Geological Congress last August, Morner estimated a total of 5 to 15 cm rise of sea level by 2100. The figure will not change, he claimed, even if there is an immediate ban on CO2 emission. A regrowth of of the ice sheets in the northern hemisphere is not expected before 50,000 years from now, as the warmer climate is supposed to continue till then.

Reacting to his critics? comments, Crichton has said that the climate scientists? forecasts are useless as human contribution to global warming has not been taken into consideration. ?Most environmental principles have the affect of preserving the economic advantages of the West and thus constitute modern imperialism towards the developing world. It is nice saying: we got ours and we don?t want you to get yours because you will cause too much pollution.?