Sunday, August 30, 2015

Global Warming:

Is it Real?

Although this is a blog devoted to nuclear issues, I keep finding myself drawn into the discussions of climate change.  This seems a very relevant issue for nuclear power, because it is the most reliable source of low-carbon energy.

Therefore, I've made a great effort to learn more about the arguments over climate change--whether it is real, whether it is man-made, and whether we should be doing anything about it.  Despite all my efforts, I remain perplexed.  I'm not a climate scientist, so I have a hard time sifting out what is true and what is not, what is important from what is unimportant: 

  • One day, I read a report that the global temperatures are rising.  The next day, I see a study says that depends on where you measure.  Still another report insists that temperatures fell last year, and that, in turn, is rebutted by the argument that one year doesn't matter.  
  • Some say it isn't the global average temperature that is the problem, but rather regional effects.  Or that the problem is really the changes in weather patterns--more severe storms, more widespread droughts, etc.
  • Other reports detail the changes that will take place in the world.  Parts of the world will be washed away by rising seas, but other areas will benefit from longer growing seasons and temperatures conducive to a wider range of crops.

  • I see accounts of what we must do to get the problem under control--cut down our use of fossil fuels, conserve more, replace current technologies with advanced technologies.  It sounds expensive, but doable.  Then, I read yet another report that makes it sound like it's too late anyway.  The problem is so large and the changes are moving so fast that nothing we can do can turn back the inevitable. 
  • Some reports point to historical changes in global temperature and therefore conclude that it is all natural, and we can't do anything about it.  Or shouldn't to anything about it.  Or, once again, that nothing will work anyway.
  • Others say that maybe we should just plan for the changes--build dikes around our low-lying cities, move some of our infrastructure to higher ground, learn to seed clouds to control adverse weather phenomena.  

So what should we make of all these contradictions?  We sometimes lose sight of the fact that carbon dioxide is only one of the side products of fossil fuels.  Long, long before I ever heard of the problems of carbon dioxide emissions and global warming, I heard about smog.  So that might argue that there one more reason should be trying to move to cleaner fuels anyway.  Or, to cleaner ways to use the existing fuels. 

The answer to that, of course, is--at what price?  If we are really in imminent danger of flooding cities that are home to hundreds of millions of people, and if human action can address the issue, most people would be willing to pay a pretty high price.  If there really is a high degree of uncertainty, or if we don't think any actions we take can affect it, then, we might still be willing to pay something for cleaner air, or to reduce the consequences of climate change, but what we should do becomes more of a cost-benefit issue.

I therefore was very interested to discover a Wall Street Journal article by Stephen Koonin, Director of the Center for Urban Science and Progress at New York University.  The article, entitled "Climate Science is not Settled," is almost a year old, but in case other non-subscribers to WSJ didn't see it last year, I think it is worth a read.  It identifies some of the many reasons that I keep seeing these contradictory reports:  the variability of natural climate change; the lack of full understanding about the role of the oceans; the roles of water vapor, clouds, and temperature; the deficiencies of existing models, including the fact that they do not use a fine enough grid, the failure to account properly for the behavior of the sea ice at the two poles; and other uncertainties.  Koonin calls for improvements to models and more rigor to "stress test" them.

But I find some of his final comments the most interesting.  He says, "Policy makers and the public may wish for the comfort of certainty in their climate science. But I fear that rigidly promulgating the idea that climate science is 'settled' (or is a 'hoax') demeans and chills the scientific enterprise, retarding its progress in these important matters. Uncertainty is a prime mover and motivator of science and must be faced head-on."

He further says, "Society's choices in the years ahead will necessarily be based on uncertain knowledge of future climates. That uncertainty need not be an excuse for inaction. There is well-justified prudence in accelerating the development of low-emissions technologies and in cost-effective energy-efficiency measures. But climate strategies beyond such 'no regrets' efforts carry costs, risks and questions of effectiveness, so nonscientific factors inevitably enter the decision. These include our tolerance for risk and the priorities that we assign to economic development, poverty reduction, environmental quality, and intergenerational and geographical equity."

Finally, he concludes, "Any serious discussion of the changing climate must begin by acknowledging not only the scientific certainties but also the uncertainties, especially in projecting the future.  Recognizing those limits, rather than ignoring them, will lead to a more sober and ultimately more productive discussion of climate change and climate policies. To do otherwise is a great disservice to climate science itself."

I think that would indeed be a rational way to approach a very difficult, but very important, issue.


No comments:

Post a Comment