re: #8 Occasional Reader

And average temperatures have flatlined in the last decade, in spite of this ongoing, cumulative problem, because…

Because we’ve had a bit of luck with the forces of nature that play their own part in the climate.

Those forces are not on our side though. They’re indifferent. Our luck can turn. It turns, from time to time.

Two degrees Celsius is not trivial. A growing season can be made or broken by those two (more than 4, Fahrenheit) degrees. Every day, that much warmer than it would have been—-if you’re in for a hot dry summer anyhow, those two degrees are the last nails in your coffin.

For Saskatchewan farmers, and North Dakotans, and Alaskans, and Russians, this warming, should it occur, would probably be a good thing. For Vietnamese, it’s surely a bad thing. Rice is a warm-weather crop, but there’s still such a thing as too hot for rice, and warm years mean poor harvests. Two degrees more means that on top of the usual zigs and zags, there are more bad harvests in store and fewer good ones.

Already there have been panics in the price of rice. Financial Times on “The global food crisis”

Two degrees more is bad for New Orleans. It’s muggy enough there already. The ocean has already taken one damaging whack at the town, and sea level will rise, at least a bit, with rising global temperatures. Suppose it’s two centimeters. Trivial, right? But the flat lands of Louisiana, and Bangladesh, and many other places, grade only very gradually upward. The last mile of marshes becomes just too saline for the trees. They die, and storms can lash inland that much further without hindrance.

Ice shelves in the Antarctic are breaking up. Google Wilkins. The Notices of the American Mathematical Society, April issue, has an article on Arctic sea ice. Figuring out all the ins and outs of how sea ice forms and whether it will mostly disappear in the summer if we get those two degrees of warming is a desperately difficult problem, and today’s models are not good enough. But in that uncertainty, one thing is clear: for all we know, it could mostly disappear. Another thing is clear: straight, simple minded extrapolation of current trends, (which is not very sound prediction, but again, it just might happen that the trend is robust), says it will mostly disappear. The current trends are stark and dramatic.

In the event things do go this way, and the Northwest Passage opens for summer seafaring in most years, that will have an upside for navigation. But ice reflects sunlight, while open water mostly absorbs it. The summers in the arctic would be that much warmer, as the north pole became less of a source of intensely cold winds even in summer.

My Dad quit smoking before all the evidence was in. As a surgeon, he’d seen enough lung cancer patients to connect the dots for himself. Science has to be sure, but prudence can take a hint and act before the last piece of the jigsaw puzzle has clicked into place.

We would be prudent to figure that two degrees warmer is in the cards, that it won’t be good for us, and that we need to get to work now on mitigation and on preventing the next two after those two, and the next two after those.

Wind, solar, nuclear, efficiency, carbon sequestration, … we cannot put all our eggs in one basket. We need to place modest bets at each table, and see how the technology comes along. As and when good choices come along, then we need to implement them large scale and quickly. Compact fluorescent bulbs are a decent example, though there are promising developments in LED’s that may make CF’s obsolete. “Smart buildings” might be another.