In my prior post on Michael Crichton, I wrote about how Mr. Crichton had taken the time to evaluate the computer models that have led so many people to have such strong concerns about a global warming crisis. Mr. Crichton found them lacking, particularly with respect to predicting doomsday scenarios. I stated that I haven’t looked at the models, but I admired him for taking the time to look at the evidence and coming to his own opinion.

My friend Michael Hartl, a Caltech PhD, is also a skeptic. He agrees global warming is factually true, but doesn’t find it convincing that it must be due to human activity or that the warming will likely lead to some type of doomsday. Here’s his post on the subject: http://eikonoklastes.org/articles/2007/09/05/global-warming

You can also add the famed physicist Freeman Dyson (wikipedia) to the list of global warming doomsday skeptics. He elaborates on his opinions about such warming to a great degree in an article in Edge issue 219 (http://www.edge.org/documents/archive/edge219.html#dysonf).

His basic points are:

• Science sometimes can’t yet provide an answer; but the public will choose one anyway. Even when science lacks understanding, the public prefers to listen to confident answers and predictions by the consensus opinion of the most vocal scientists of the day. That is why heretics who question scientific dogmas have been and will continue to be useful in science, particularly on things that aren’t well understood.
• Climate isn’t properly described by computer models; it’s described by data. Global climate is a very complicated thing, and the causes of warming or cooling are not well understood. Climate computer models solve the equations of fluid dynamics, and they do a very good job of describing the fluid motions of the atmosphere and the oceans. They do a very poor job of describing the clouds, the dust, the chemistry and the biology of fields and farms and forests, which appear to have a significant impact on climate. They therefore do not begin to describe the real world that we live in. Diseases must be diagnosed before they can be cured. We need to observe and measure what is going on in the biosphere, rather than relying on such computer models.
• Warming is local. It’s true parts of the Earth are getting warmer, but the warming is not global. The warming effect of carbon dioxide is strongest where air is cold and dry, mainly in the arctic rather than in the tropics, mainly in mountainous regions rather than in lowlands, mainly in winter rather than in summer, and mainly at night rather than in daytime. The warming is real, but it is mostly making cold places warmer rather than making hot places hotter. To represent this local warming by a global average is misleading.
• Technology to fix things improves over time. If biotechnology takes over the planet in the next fifty years, as computer technology has taken it over in the last fifty years, the rules of the climate game will be radically changed. To stop the carbon in the atmosphere from increasing, we only need to grow the biomass in the soil by a hundredth of an inch per year. … the problem of carbon dioxide in the atmosphere is a problem of land management.
• Sea level is rising, but not necessarily because of humanity’s actions. We have accurate measurements of sea level going back two hundred years. We observe a steady rise from 1800 to the present, with an acceleration during the last fifty years. It is widely believed that the recent acceleration is due to human activities, since it coincides in time with the rapid increase of carbon dioxide in the atmosphere. But the rise from 1800 to 1900 was probably not due to human activities. The scale of industrial activities in the nineteenth century was not large enough to have had measurable global effects. So a large part of the observed rise in sea level must have other causes. One possible cause is a slow readjustment of the shape of the earth to the disappearance of the northern ice-sheets at the end of the ice age twelve thousand years ago. Another possible cause is the large-scale melting of glaciers, which also began long before human influences on climate became significant.
• The threat of an Ice Age is still very real, and it’s not clear how warming effects this threat. For the last 800,000 years every 100,000 there is an ice age lasting 90,000 years and a warm interglacial period lasting 10,000 years. We are at present in a warm period that began 12,000 years ago. We do not know if human activities in general, and burning of fossil fuels in particular, make the onset of the next ice-age more likely or less likely.
• A warmer world has existed before, and could have benefits. Roughly 6,000 years ago, there were deciduous forests in Northern Europe where the trees are now conifers, proving that the climate in the far north was milder than it is today. There were also trees standing in mountain valleys in Switzerland that are now filled with famous glaciers. 6,000 years ago seems to have been the warmest and wettest period of the interglacial era that began 12,000 years ago when the last Ice Age ended. If the increase of carbon dioxide in the atmosphere is allowed to continue, shall we arrive at a climate similar to the climate of 6,000 years ago when the Sahara was wet? Second, if we could choose between the climate of today with a dry Sahara and the climate of 6,000 years ago with a wet Sahara, should we prefer the climate of today?
• Two different types of values. The science of planetary ecology is still young and undeveloped. It is not surprising that honest and well-informed experts can disagree about facts. But beyond the disagreement about facts, there is another deeper disagreement about values. The disagreement about values may be described in an over-simplified way as a disagreement between naturalists and humanists. Naturalists believe that nature knows best. For them the highest value is to respect the natural order of things. Any gross human disruption of the natural environment is evil. Excessive burning of fossil fuels is evil. Changing nature’s desert, either the Sahara desert or the ocean desert, into a managed ecosystem where giraffes or tunafish may flourish, is likewise evil. The humanist ethic begins with the belief that humans are an essential part of nature. Humans have the right and the duty to reconstruct nature so that humans and biosphere can both survive and prosper. For humanists, the highest value is harmonious coexistence between humans and nature. The greatest evils are poverty, underdevelopment, unemployment, disease and hunger, all the conditions that deprive people of opportunities and limit their freedoms.

Definitely more food for thought.