Greenhouse catastrophe

All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self evident. ~ Arthur Schopenhauer, 1788-1869.

If one believes that science is an orderly march to the truth, he will be surprised at how sharp the disagreements are. The consensus of scientists is a very weird thing. The issue of global warming from greenhouse gases (GHGs) ~ carbon dioxide, methane, ozone, water vapour and nitrous oxide ~- is a case in point.

For years scientists have debated the issue of global warming. The climate sceptics are of the opinion that the atmosphere, ever in quest of stability, triggers its own natural immunity by activating the buffer mechanism (negative feedback process) that serves as a thermostat to maintain a temperature level. As the earth’s temperature rises, more and more water vapour loads the atmosphere which, in turn, may lead to forming more clouds. But clouds warmed by GHGs will produce rain more efficiently than cooler clouds, and thus both the humidity and the greenhouse warming will get reduced. It has also been claimed that the earth’s climate system is so resilient that it can, in any event, absorb unlimited quantities of GHGs without any harmful consequences. To them the term ‘Greenhouse effect’ is a total misnomer. There are more than 100 other misleading, peripheral, irrelevant, false, and unscientific arguments that are pushed relentlessly in the media by climate sceptics.

Warming of the climate system seems to be self-evident. Many of the extreme weather disasters that have claimed so many lives and caused so much suffering are now directly linked to global warming. “Warming of the climate system is unequivocal”, according to the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC), a consensus document produced by over 2,000 scientists representing every country in the United Nations. The earth’s surface over each of the last three decades has been warmer than any preceding decade since 1850, and has warmed by 0.85 degree Celsius on an average since the pre-industry era. The five hottest years in the entire 20th century occurred in the decade of the 1980s. The decade 2001-2010 was the warmest on record, the UN’s World Metrological Organisation (WMO) noted. Significantly, some regions, like the Arctic and the Himalayas, are warming much faster than this average and the temperature rise has reversed, indicating a downward trend in the earth’s average temperature.

The IPCC’s Fifth Assessment Report (AR5) has also warned of the possible impacts of the overwhelming global warming ~ all countries and all social classes will be affected by changes which are likely to be “severe, pervasive and irreversible.”

The devastating effects of global warming are already palpable. Cold days, cold nights, and frost have become less frequent, while heat waves are more common. Globally, precipitation has increased even as Australia, Central Asia, the Mediterranean basin, the Sahel, the western part of the USA, and many other regions have seen more frequent and more intense drought. Heavy rainfall and floods have become more common, and the damage caused by storms and tropical cyclones have increased. During a one-century time scale, the human-induced climate change has been occurring so fast that it gives society and the ecosystem little time to adapt to the rapid speed. According to a study by Princeton University researchers, global warming is facilitating the spread of bacteria, viruses, and fungi that cause human diseases into areas that were formerly hostile to them. Crop diseases and pests are increasing with global warming. Water resources, already under stress, are likely to come under even greater stress. The impact of global warming through diseased agricultural yields, floods, drought and desertification will be felt more intensively mostly in the tropical zones. Animal species face an increased risk of extinction. The best estimates of species losses suggest that around 10 per cent of species will be condemned to extinction for each 10° C temperature rise, with even greater numbers at risk for significant decline.

Throughout the history of urban civilisation, the seas have been slowly and gently rising, as the warmer temperatures of the interglacial period have caused the thermal expansion of ocean water and the melting of terrestrial ice. The rise in the sea-level, witnessed in the 20th century, seemed largely to be linear ~ about one-third of its rise came from thermal expansion ~ from the fact that water increases in volume as it warms. Indeed, during the last half century, global warming has accelerated the melting of ice almost everywhere on the planet. So far it has been mostly mountain glaciers, but the major concern for the future is the giant ice-sheets in Greenland and Antarctica. Climate scientists now estimate that Greenland and Antarctica combined have lost on an average about 50 cubic miles of ice each year since 1992 ~ roughly 200 billion metric tons of ice annually. The main sources of the rise in the sea level in the 21st century will be the melting of ice-sheets on Greenland and Antarctica, a non-linear process. Since 1900, the global sea-level has risen about eight inches. It is now rising at about an eighth of an inch a year. If the accelerated melting of Greenland and Antarctica ice-sheets continues, by the end of the 21st century the sea-level rise would be as much as six feet globally. In case the massive Thwaites Glacier in western Antarctica breaks free from its rocky berth, the sea-level will rise by three meters ~ nearly ten feet.

Using a conservative prediction of a half-meter rise in the sea-level, the Organisation for Economic Cooperation and Development (OECD) estimated that by 2070, as many as 150 million people in the world’s large port cities will face the risk of coastal flooding. A recent study states that the water-level in the Sundarbans has been rising at the rate of 3.14 mm per year. “Climate refugees” from coastal areas of Bangladesh have already crowded into the city of Dhaka.

Agricultural areas in low-lying coastal regions are already suffering from the intrusion of sea-water into their freshwater aquifers caused by sea-level-rise. More than 30 percent of CO2 emissions end up in the oceans, turning them gradually more acidic. The resultant acidification seems to impact many forms of sea organisms, especially those whose shells or skeletons are made from calcium carbonate like corals and shell fish. It also interferes with the reproduction of the plankton species which are a vital part of the food web under the sea. Acidity of sea water has also resulted in coral bleaching by expulsion of symbiotic algae. The ocean acidification has been dubbed as the ‘Evil Twin’ of climate change. Even if we stop emissions now, ocean acidification will persist for thousands of years.
The message of the IPCC and climate scientists is crucial and unambiguous. Today’s fossil-fuel-driven civilisation is altering the planet profoundly through changes in the earth’s climate and ocean chemistry. The protracted climate change negotiations are going nowhere with nations entangled in a ‘prisoners’ dilemma. One country suspects the motives of the other; they agree to take measures only if others do so. A worldwide consensus is urgently required to soften the impact of greenhouse gases. Edmund Burke had once remarked: “The only thing necessary for evil to prevail is for good men to do nothing.”