No matter which line you prefer on the graph, you can’t draw any firm conclusions about the IPCC’s projections — a few years does not a trend make, and the global temperature is just one of the indicators to look at. But the different lines on the graph are certainly evidence of how complicated the climate debate is. If scientists can’t even agree on what has happened in the past, imagine how much more difficult it is to figure out the future. I’m not suggesting that the global warming isn’t real, or that the uncertainties justify inaction — we take out insurance all the time against risks that are uncertain. I’d like to see a carbon tax. But I’d also like to see fewer dogmatists claiming that the scientific debate is over.
Dr. Pielke suggests that more scientists do reality checks on other predictions by the IPCC, and that the IPCC make it easier for its predictions to be tested by specifying in detail what the variables are, who is measuring them, and what to look for in the future. “If weather forecasters, stock brokers, and gamblers can do it, then you can too,” he urges the IPCC in his blog post. Dr. Pielke told me that scientists have been focusing on the predictions for the summer ice melt in the Arctic — which called for less dramatic change than what has actually occurred — but not paying enough attention to other indicators.
“Rather than select among predictions, why not verify them all?” he said. “Seven years is not a lot to allow much to be said, but certainly 10 and 15 years will be. Once predictions are made, they should not be forgotten, but evaluated against experience. This is not skepticism at work, just the good old scientific method.”
Good advice.
No comments:
Post a Comment