Monday, December 5, 2011

Overcoming uncertainty

As you probably know, the climate change negotiations for the year have been under way in Durban for the past week. And for another year, large, industrial nations will skirt the issue, citing economic downturns and uncertainty of how much the Earth will warm in the future because of greenhouse gas emissions. In the spirit of action, however, I continue to encourage action in the face of uncertainty. 

Why is Climate Sensitivity So Unpredictable?, written by Gerard Roe and Marcia Baker of the University of Washington, is one of the most fascinating scientific papers I have ever read. Here is the abstract (don't worry if you don't understand exactly what they are saying, just skip the next paragraph...for the science-minded, the paper is beautifully straightforward compared to other scientific papers):
Uncertainties in projections of future climate change have not lessened substantially in past decades. Both models and observations yield broad probability distributions for long-term increases in global mean temperature expected from the doubling of atmospheric carbon dioxide, with small but finite probabilities of very large increases. We show that the shape of these probability distributions is an inevitable and general consequence of the nature of the climate system, and we derive a simple analytic form for the shape that fits recent published distributions very well. We show that the breadth of the distribution and, in particular, the probability of large temperature increases are relatively insensitive to decreases in uncertainties associated with the underlying climate processes.
(Resume reading here) The authors go through some very elegant mathematics to show, basically, that regardless of how much future work is done in reducing the uncertainties of how much global mean temperatures will rise because of increasing greenhouse gas emissions, the bounds of climate sensitivity (the increase in global mean temperatures resulting from a doubling of carbon dioxide emissions) will still be wide. To boil it down even further, even if we continue researching the climate system for another decade, or two, or three, we may still be stuck with saying, "Temperatures will rise between 3.6-8.1 degrees Fahrenheit." What does this statement mean? It means that we are uncertain how much the temperature will rise, but we are certain that it will rise to a number between than range. Indeed, the uncertainty surrounds the magnitude of temperature rise, not the actuality of temperature rise as a whole. Unfortunately, uncertainty allows the powerful, who don't understand the notion of it, to dither on decisive action. And for all of our efforts, we might still be waving the Maldives goodbye, regardless if some new paper comes out saying that climate sensitivity lies between 3 and 4.7 degrees Fahrenheit.

But there are ways to counter uncertainty, and that is through the tangibility of our choices. And to that end, I want to reiterate what I said last April:
How can we deal with the fear of uncertainty, knowing that we are degrading what it is that sustains us, but are so invested in the way it is, that we kick the stone down the road? This world has always been an uncertain place to most people, and yet to me, there is a beautiful certainty about it. Rather than think and worry about the future, we can all make decisions here and now such that tomorrow will be a good day. We all want to live in a world in which what we cherish is alive, healthy and sustained. To live in that world, we must act in such a way that we cherish, respect and sustain now, today. It is not complicated. If I respect and cherish my relationship with my friends and family today, those relationships will grow stronger and more resilient; tomorrow those people will still love me, and I will still love them. I do not have to live in the fear of a grudge or a toxic conversation. If I respect the tree and the river today, they will be healthy and full of life tomorrow. Now is easier to comprehend and experience and think about. Acting well now will save us much trouble tomorrow.
 I stand by these words more than ever before. Such choices in the face of uncertainty nip uncertainty in the bud, for we abstain from being complicit in ecologically degrading behaviour. There is nothing uncertain about that.

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