Posted by CKR
George Will the other day repeated a mantra: no such thing as global warming. That’s a convenient position for those who want to continue to sell obscene amounts of oil and coal.
There are also scientists who seem to want to convince us that the sky is falling. They too have a self-interest. If global warming is real, they are the best qualified to receive research grants and continue a successful career. Even if there’s not a problem and they receive grants for long enough and make a big enough splash, their career is assured. However, those I would put in this category are more judicious in their statements than they were several years ago.
An essay by Naomi Oreskes in the 3 December Science magazine, shortened for the Washington Post, takes a middle ground: the overwhelming consensus among scientists is that humans are doing things, like burning fossil fuels, that increase global warming, but the details of both cause and effect are poorly known.
I’ve had some experience with computer modeling like the climate scientists do, and I have some doubts about its ability to give us those details. The modeling I was involved with was for process vessels of, say, several feet max diameter. Expand that vessel to the size of the earth, and there are an enormous number of variables that can’t be modeled well, or sometimes at all. For only one example, climate models left out clouds until fairly recently.
But there are some things you can get out of those models. Similar models have produced today’s computer-controlled fuel-efficient automobile engines. That worked well enough. And modeling of the polar ozone hole (different from global warming) and the effects of removing chlorocarbons from commerce has tracked well.
Measurements are necessary to tie the models down to reality. It’s hard to measure climate, which is made up of many, many, possible observations. Climate models can be made to fit past observations, but the tinkering that is necessary brings into question whether they accurately predict the future. Tinkering is acceptable in models of this kind, but too much means that you’ve got the model wrong. And some models fit one kind of data but not another.
Here is a web site with some of the recent climate changes that have been observed in the Arctic. Nice photos.
Finally, we know that climate changes, with or without the intervention of human beings.
Even with those uncertainties, there are some things that can be said: the concentration of carbon dioxide in the atmosphere has been increasing since industrialization required the burning of large amounts of fossil fuels; we are seeing some of the effects that the models predict for global warming.
Something is happening, and it is not unreasonable to tie it to higher carbon dioxide concentrations in the air, along with other man-made effects.
What do we do about it? That depends on those dicey details of the models, so it’s a harder question. Some stand to benefit from possible effects and others to lose: while the US’s Great Plains become more arid, conditions for grain farming may improve in Canada and Russia. Rising sea levels and the ending of Gulf Stream flow and therefore a frigid Europe seem to be to nobody’s benefit, however.
It seems minimally prudent to begin to decrease carbon dioxide emissions. Some companies, like British Petroleum, claim to have profited by improving efficiency and decreasing emissions. This is the aim of the Kyoto Treaty, which has come into force with Russia’s signing. Perhaps the market for emissions credits will convince the US to join.
[BTW, “Climate change” is the neutral term and is now preferred by scientists. “Global warming” implies conclusions about effects.]