In the long run, the question of how much human activities are contributing to climate change is an important one. While a substantial majority of climate scientists agree that overuse of fossil fuels and other factors do contribute significantly, the possibility remains, however slim or substantial you might judge it to be, that over geological spans of time, the Earth's climate fluctuates naturally on a spectrum between ice ages and global warming. As I've said before, this is a question that should be resolved on the basis of science, not opinion, notwithstanding the fact that we seem to be living in a time when many vocal non-scientists seem to think that science and opinion/religious interpretation deserve equal consideration. (As the Dalai Lama said, "Someone whose faith is not grounded in reason is like a stream of water that can be led anywhere")
In the shorter term, we have to deal with the reality that, whatever the causes, we are in a period of climate change in the warming direction. According to the National Oceanic and Atmospheric Association (NOAA), more than 50 percent of Americans live within 50 miles of a coast and that number has been increasing substantially over the past 30 years. Add to that the population who live in non-coastal flood plains, e.g., near rivers and major streams, and you have a significant portion of the population whose lives and livelihoods are affected by rising sea levels and by rain in areas and at times when not long ago there would have been snow. Areas around Lake Tahoe in this latter category include Truckee, and in the greater region, we've just seen Reno and Sparks gearing up for potential major damage. In 1997, we saw Reno flooded significantly when the Truckee River overflowed its banks.
While the nature and necessity of societal response to long-term climate change may be considered to be debatable (and while I don't think it is, I'm aware that others disagree), the need to respond to the short-term issues is not. We've seen what rising sea levels combined with a weather emergency can do in coastal communities from New Orleans to New York, and having seen that further loss of life and property without significant attempts to defend against them is politically, societally, and humanly unacceptable.
Make no mistake, there is a limit to what we can do. Earthquakes, tornados, superstorms, tsunamis and other cataclysmic weather events will continue to occur and there will be damage and loss of life. Nonetheless, it is our responsibility as citizens and the government's responsibility as well to do what can be done to minimize these effects. In Hawai'i, for example, the State and local goverments have detailed plans to do this -- tsunami warning sirens, organized evacuations to higher ground, and significant efforts to educate citizens and visitors so that when execution of these plans is needed, things go generally smoothly and effectively.
This distinction between the long-term and short-term issues of climate change is important. When they are lumped together, those whose economic interests and/or religious convictions are threatened by the consideration of human contribution to the long-term effects rally against efforts to do something about protecting against the short-term effects, whatever their causes, and lives and property are lost.
The regular reader of this column knows that, by training and disposition, I am a rationalist, and an empiricist, which is to say I am biased toward a scientific approach and I trust the scientific interpretation of data to create theories that can be tested and revised as new findings arise, or that can be promoted from the status of theory to that of scientific law, which is itself subject to revision. Those who do not wish to deal with science claim this constant revision invalidates science and prefer to cling to rigid, if unsubstantiated, belief. That is their right, but it leads to a kind of fatalism that I abjure, and as the Dalai Lama said, it creates the danger of being led around by the nose. Either way, if we are not to simply be victims of the vagaries of weather and climate change, we need to be vigorous in our approach to both the possibilities of human contribution to climate change and to the need to protect ourselves from its effects, regardless of the causes.