The topic of warming is currently receiving much attention. Despite the uncertainty surrounding this issue, global warming is a cause of concern for many people. The burning of fossil fuels and deforestation are the human activities that most affects the concentration of greenhouse gases, such as carbon dioxide. Increasing concentrations of greenhouse gases will cause average earth temperature to rise with catastrophic consequences. This change in our climate poses direct and severe threats to human health by increasing the occurrence of infectious diseases, heat stress, extreme weather events, and dangerous levels of localized air pollution. While there is general agreement that greenhouse gas concentrations have increased, some people do not believe this increase is causing global warming, and if it is, whether there is a danger of catastrophic climate change.

        I believe that global warming is not a theory but a fact. Yes, it’s true that while evidence exists that suggest a problem, there is no direct and definitive proof that global warming is a serious, long-term threat, or that people are a significant factor. For the sake of argument, let’s assume that the minority of scientists, who claim that global warming is a ordinary climatic cycle of the earth, are right and global warming is "safe". The Earth’s climate is a dynamic system that is driven by the energy of the sun. Thus, we might conclude that variations in the sun’s energy will change the climate. If the global warming is just a part of a long-term natural cycle, then there probably is not much we can do about it. But shouldn’t we be saving our energy resources (especially fossil fuels) for those difficult times to counteract the effects? Some people believe that global warming and even the next ice age are minor problems compared to higher solar radiation that may make the Earth too hot to support life in about a billions years. But in principle, even if global warming might not be a threat to life on Earth as we know it, some consequences should be expected.

        On the other hand, if the vast majority of scientists are right, and the present warming trend is the result of increases in greenhouse gases then there is much we can do. We can contribute to reducing greenhouse gasses by reducing our demand for energy to burn less fuel. Whichever scientific approach is valid, it requires some action from us. Global warming calls for energy conservation and energy efficiency.

        As a last note, it is important to mention that problems with energy supply and use are related not only to global warming, but also to such environmental concerns as air pollution, stratospheric ozone depletion, forest destruction and emission of radioactive substances.

Very good presentations on this subject are:

Greenhouse Effect and Global Warming

Global Warming

Global Warming: Focus on the Future