re: #389 vinnievin

Yes, denial of science is dangerous. What concerns me is how, when almost every topic other that manmade global warming is discussed, there is a presence of qualifiers such as ‘as far as we know’ or ‘it appears that’ and a wealth of words and phrases with the same type of meaning. But when it concerns climate change, it is a fact that everyone knows is true and if you don’t, you are stupid or paid for.

Well, now. Do we really write that `it appears that vaccination increases immunity to polio’, or `as far as we know, when there is rain, water levels in rivers rise’?

As far as we know, when global CO2 levels go up, temperatures tend to go up too. To the best of our knowledge, though who can be sure, (for the memories of old folk are fickle, and who can trust photographs?), there used to be over 100 glaciers in what, for some quaint and unaccountable reason, is called “Glacier” National Park.

There is some reason to suspect that there are now shrubs growing on extensive areas of the Alaskan North Slope. People go there and take pictures and it looks like those are shrubs. They walk up to the shrubs and pull off twigs, and they look like twigs. They bring back the twigs and scientists say, that looks like a twig to me, but I’ll have to check with a colleague before we can be sure.

In 1944-45, there was an aerial survey of that area of Alaska. No shrubs then. But maybe their cameras had software that edited out shrubs. Who can be sure? We don’t know for a fact that they were using analog cameras, now do we?

Scientists suspect that coal is being mined around the country and burned in power plants, and some hypothesize that similar activities go on in other countries. Our grounds for this hypothesis is that when we travel, we sometimes drive along highways paralleled by railroads, and many trains carrying what appears to be coal are heading South from what might be Wyoming. We also read about coal mine disasters in the newspaper, and we wonder—-why do they call them coal mines? Maybe because coal is being mined there?

And then it gets to the point that we say to ourselves, f* it. We know damned well those are coal mines. We know for a fact that CO2 levels are rising, we know for a fact that CO2 is a greenhouse gas, and the evidence that this is causing those shrubs to survive where before, winter killed them, that it is causing those glaciers to fail, where before, winter sustained them, is overwhelming. We are no more obliged to tiptoe around this conclusion, than we are obliged to tiptoe around general relativity, or the effectiveness of vaccines, or the fact that they don’t cause autism, or the reality of evolution as the origin of species.

There is, yes, great uncertainty as to how much the climate will change, and how fast. We don’t know exactly how fast the ocean will go on absorbing CO2; mixing rates are important and those depend on weather patterns and those are notoriously fickle. We don’t know whether warmer climate in the arctic will lead to more evaporation of water from the northern seas, and thus more snow on land and a whiter arctic, (negative feedback), or whether, on the other hand, the earlier spring melt, which turns that white to green whenever it occurs, will prevail (positive feedback.) But we do know that there are positive feedback loops in operation, and so we warn: it is reasonably possible, the probability is far from negligible, that we’re in for accelerated warming. It is reasonably possible that there are tipping points ahead. It is even possible that we’ve crossed some of them.

Anybody who ever buckles their seat belt should see the sense in taking real hazards into account. You just never know when there will be a smashup. You do know one is possible.