Global Warming and Fatal Weather

Despite the critics, there has been a growing consensus among scientists that human activity may be a compelling factor in the Earth's changing climate. The accumulating evidence of global warming, combined with a greater understanding of the influence of aerosols, led the IPCC (Intergovernmental Panel on Climate Change) to make its revised estimates of warming in its preliminary assessment report, issued in October.

Fossil fuels such as coal, oil and natural gas are the lifeblood of the world economy and are essential to poor countries that are struggling to industrialize and raise their standards of living. At the Earth Summit, developing countries were specifically exempt from the protocol to meet emission standards.

Developing countries contend that wealthy countries have contributed most to the already high concentration of CO2 in the atmosphere, and so should carry most of the economic burden for reducing it. Per capita emissions of CO2 in the U.S.--nearly 20 metric tons a year as of 1991--are about 10 times those of China, for example.

A study by Yale University's Center for Environmental Law and Policy predicts, however, that this will change quickly with the rapid pace of industrialization taking place in those countries. The study "shows that the impacts from developing countries can no longer be ignored like they have been to date and were at the Earth Summit," says Daniel Esty, director of the center. He expects China and other developing countries to emerge as the main emitters of CO2 in 25 years or so.

Some countries that would face a disproportionate amount of ecological harm if global warming occurs are also adamant that wealthier countries should take stronger steps to reduce CO2 emissions. The rest of the world has "not yet been able to find words as clear and true as the fear we islands feel for our own fate and for the fate of the climate system," pleaded Tuiloma Slade, a Samoan delegate to the conference in Berlin.

Small island states fear that the melting of polar ice caused by global warming could raise sea levels and overwhelm their nations. Trinidad and Tobago, an island country in the Caribbean Sea, presented to the Berlin conference a proposal that would have required industrialized countries to lower their emissions of CO2 to 20% below 1990 levels by 2005. But the proposal was strongly opposed and ultimately killed by larger nations that were unwilling to implement such measures, citing high economic costs.

Some scientists in the 1970s began predicting that the increase of levels of certain types of gases in the Earth's atmosphere, likely caused by human activities such as industry and agriculture, would trap heat near the Earth's surface. Like the windowpanes of a greenhouse, the slightly transformed atmosphere would raise global temperatures (a process known as global warming), leading to a melting of the planet's ice caps, a rise in sea levels and a change in weather patterns, they claim.

Environmentalists have stressed the dire ecological and social problems that they believe could result from a global rise in temperature. They have been seeking worldwide agreements to limit emissions of greenhouse gases thought to be linked to global warming. Emissions limits are opposed by those who argue that the economic and social costs of such a strategy would be too high and that there is not enough evidence of global warming to merit such restrictive policies. They point to satellite data indicating that world temperatures have held steady over the past decade.

Observers also note that the primary sources of greenhouse gases are the burning of fossil fuels, such as oil, coal and natural gas, which are the world's main energy sources. Rash policy measures intended to cut emissions would be costly for industry, and could cripple the world market economy, according to many analysts. Forced conversion to alternative energy sources and capping emissions from fossil fuels could stifle industrial growth and unfairly burden developing countries, which are especially sensitive to fluctuations in energy prices and are already weighed down with economic debt, they say.

The first warnings of global warming were dismissed by some scientists and analysts as hasty and inaccurate, and based on premature conclusions and insufficient data. Over the last few years, however, a cautious and balanced approach to global-warming research has led to a greater consensus among scientists that the Earth may be warming.

Predicting the weather, however, is notoriously difficult for scientists, who must decide whether modern weather patterns are linked to human activity or are part of the Earth's natural variability. Because of this, most scientists are reluctant to say global warming is occurring without acknowledging that several more years of research are needed to confirm their current predictions. To date, despite the high-profile debate among scientists and economists, all of whom rely on widely varying scientific data, there is no consensus as to exactly whether or not global warming is occurring.

References - Balling, R. The "Keep Cool About Global Warming." Wall Street Journal (October 16, 1995)