CLIMATE CHANGE

May 2004
		A team of international ecologists using a computer model to predict the effects of climate change say as many as 1 million species could be on the way to extinction by the year 2050. One of the study's authors, Lee Hannah, and environmental experts Daniel Botkin and Patrick Michaels answer your questions.

Forum Introduction Will climate change act as a catalyst for new species? Is climate change the result of human activity or a natural phenomena beyond our control? Do we know anything about species extinction rates from the relatively recent "little ice age"? Can climate change be reversed, as opposed to deterred? Does the impact being made by humans in this (brief) period really explain world-wide shifts in climate? For every study that claims to observe climate change, there are others that seem to refute it. Wouldn't we all be better served by a global campaign to address air quality? What, if any, are the potential upsides of global warming?	Justin O'Brien of New York City asks: I have no doubt that climate change poses a dramatic risk to our world. However, for every study that claims to observe climate change, there are others that seem to refute it -- not to mention the climate history of our planet, which has seen many non-man-made temperature shifts. So, the public (in the U.S. especially) remains very skeptical of these claims. My question is the following: Wouldn't we all be better served by a global campaign to address air quality - which directly affects our health vis-a-vis respiratory problems? Why can't we hold major air polluters financially responsible for the respiratory ailments affecting millions of people? Wouldn't this be a more affective way of getting industries to cut greenhouse gases, rather than run in circles trying to make people believe in something like global warming? Daniel Botkin responds: The overwhelming scientific evidence supports global warming. And the overwhelming number of scientists believes that human actions are changing the climate. There is only a small number of counterclaims. They just get a lot of press, because a "debate" seems to be more interesting than a non-debate. Articles in the major scientific journals, such as Nature and Science, are in the vast majority consistent with global warming. One needs to be cautious about the amount of space in printed popular media and time on TV devoted to both sides of a scientific issue. It is not necessarily an index of what the predominant scientific findings are. Global warming was first raised as a possible consequence of burning fossil fuels in the early 19th century and has been a growing concern among scientists, especially since the mid 20th century. Scientists concerned about human societies and the well-being of people, as well as environment, have been drawn to a concern about global warming not because they want people to "run in circles" but because there is serious concern that global warming could cause major and important changes that affect us and life around us. There is much constructive that we can do which is also not running in circles. For example: Plant trees. Turn to alternative energy, which gets us past the dependence on international sources of oil. There is not an either-or choice between air pollution that affects respiratory problems and global warming. Many of the actions we would take to improve air quality for respiratory problems will also help reduce the rate of change of climate, such as reducing our use of fossil fuels, reducing dust in the air as a result of heavy truck and car traffic. Global warming will take place over a longer time, but also be harder to slow. So we need to be concerned about both. Lee Hannah responds: Unfortunately, the pollutants that cause respiratory problems are different from those that cause warming. CO2 (carbon dioxide), the main warming culprit, isn't toxic to humans except at the levels found in urban air. Patrick Michaels responds: You are very right about a global campaign on air quality. It irks me that people chase global warming when it is largely irrelevant to health compared to the downright awful air that pervades homes in Africa and India (from burning of dung and wood indoors). We could do so much more if we faced the real, solvable problems, rather than mediagenic chimeras. Also, it's worth thinking about that, in general, air quality is improved with newer technologies (even new coal-fired power plants can be made very clean), and so what we really want to do is foster investment in those technologies (by not taxing away people's profits?) for a cleaner future.