although i have a strong background in science, i’m just a lawyer, not a scientist, but have been observing the controversy over global warming for a long time. here is a summary of my impressions so far.

1. proposition: global temperatures are rising. there doesn’t seem to be any serious, evidence-based controversy over this. it may be possible to interpret data as reflecting short-term fluctuations rather than long-term trends, but the data seems to show rising temperatures over the decades that data has been collected. that doesn’t mean lay people will agree about this. but informed, reasonably objective scientists seem to be largely in consensus on this point.

2. proposition: man has caused global warming. in my view this is a credible theory with many uncertainties. the cause of global warming is not directly observable, and we know there have been massive climate changes in earth’s natural history. in my elementary school science classes in the 1960′s, our science book texts taught us that we were at the end of an ice age. if man’s activity is warming the planet, i don’t see how the portion caused by man and the portion that would have occurred but for man’s activity have been or can be accounted for separately.

3. proposition: if man caused global warming, man can reverse at least the portion of global warming he caused. this proposition seems to me to be difficult to demonstrate. first, it seems wrong to assume that if man caused something that he’s likely to be able to reverse it. if i knock a glass off a table and it spills its contents and breaks, i cannot reverse it. the burning of large reserves of fossil fuel seem to me to be highly entropic effects that may not be reversible. put differently, if i were to be convinced that man could reverse global warming, i would not consider it evidence that man has been a substantial contributing cause.

4. if man can reverse global warming, then man should reverse it. this seems to me the least likely and provable of the propositions. first, this is a policy question, not a scientific one, even though it should be considered in light of the best science available. moreover, as with all policy questions, we need an analysis of costs and benefits, discounted for time-value (the time-value of money). to make a rational decision about what to do, we have to compare the best information about the present value of all the future costs of reversible climate change (in light of the best science) with the present value of all future costs to reverse that change. if we’re rational, we will do whichever costs less. it’s also useful to observe that the present value of future costs is determined by a converging function, which means that very high costs that continue indefinitely into the future have a limited (not unlimited) present value. it seems to me that despite massive data supporting trend in increased temperature, there is inadequate data regarding the reversibility of that trend, what it will cost, and the value of benefits, to have a rational policy debate about costs and benefits. that, in my view, is why almost anyone who discusses this topic with any passion, on either side of the debate, looks more like a long-faced preacher than a rational actor. because to make a strong case on either side, you have to appeal to things that aren’t rational, like the supposed well-being of children not yet in existence or how damn cold it was in nebraska last year. in the absence of adequate information about costs and benefits, a rational person should not act. that is why, for me, inaction about climate change is the only sensible response right now. as the discussion becomes better informed with costs and benefits, that may change. the fact that it might then be too late is not a convincing reason to act now without better information.

To name just a few, how does ENSO explain away the empirical evidence of accelerating ocean acidification, glacier melt, shifting ranges for both plants and animal species, and melting permafrost?

Your last sentence is quite revealing: by conflating the scientific evidence with potential policy responses, you show you actually care most about money — and your own comfort, which you erroneously perceive to be threatened — than you do about the world you are creating for your children.

In order to say that you need to ignore the change in ENSO that is apparent in changing atmospheric pressure over the period of record. Atmospheric pressure determines wind strength and is tied in with changes in cloud cover. Atmospheric pressure is not affected by urban warming phenomena. Better look a little more closely. What you say puts peoples living standards and the possibility of economic growth for non industrialized world at stake. Be careful.

Like Nelson, you choose to look with the blind eye.