Question

What all measures are to be followed by the people to reduce, prevent or stop global warming? What are the future problems the earth is going to face due to global warming if it is not prevented? By what year the earth will face the hazards of global warming if no measures have been taken to prevent it? What are the current measures in progress to reduce global warming?

Climate change is a complex but critically important issue, with many implications for astrobiology. While most atmospheric and climate scientists agree on the global warming that has been taking place during the past century, their predictions of future heating are not all in agreement. The greenhouse gases that are most important are, first carbon dioxide, then methane and several industrial compounds such as CFCs. These are the gases that determine the strength of the greenhouse effect and hence the amount of global warming our planet is experiencing. The most straightforward ways to combat global warming are to reduce the reduce the production of carbon dioxide and methane and/or find ways to take these gases out of the atmosphere and sequester them. However, there are many things that also influence the temperature of the Earth. These include solar variability (which is monitored by space satellites) and atmospheric cooling effects of high-altitude aerosols, especially the stratospheric haze produced by large volcanic eruptions. When all these effects are taken into consideration, it has been apparent for the past 20 years that the planet is warming at an unprecedented rate, and that production of carbon dioxide is the dominant effect. About the only thing that could slow this warming significantly in the near future is another big volcanic eruption such as Pinatubo in 1991. There are many consequences of this warming. Species that cannot adjust to the rapid change will go extinct. The Arctic icecap will become seasonal, with much of the Arctic Ocean free of ice for much of the year. Diseases, especially those carried by insects, will spread to areas that become warmer. Patterns of rainfall will change, with some areas becoming wetter and others becoming deserts. Warming of the sea will produce stronger cyclonic storms, and acidification of the sea will harm many habitats for marine life, such a coral reefs. Perhaps most dramatic, the great icecaps in the Antarctic and Greenland will melt, a process that has accelerated dramatically during the past few years. The rising sea levels will flood parts of the land, starting with the lowest areas such as the river deltas of Bangladesh, southern Florida, and many islands in the Pacific and Indian oceans. When will all this happen? No one knows, but most of these things are likely within the 2ist century, and some are happening already. See the Wikipedia article on global warming and other websites that suggest ways to slow or reverse these trends.
David Morrison
NAI Senior Scientist
August 21, 2008