THE EARTH is warming. A chief cause is the increase in greenhouse gases accumulating in the atmosphere. Humans are at least in part responsible, because the oil, gas and coal that we burn releases these gases. If current trends persist, it's likely that in coming decades the globe's climate will change with potentially devastating effects for billions of people.
Contrary to what you may have read lately, there are few reputable scientists who would disagree with anything in that first paragraph. Yet suddenly we're hearing that climate change is in doubt and that action to combat it is unlikely. What's going on?
First, climate science is complex, and there is much that we still do not understand. Politicians, advocates and scientists who have claimed a level of certainty unsupported by evidence -- about exactly how climate change will unfold or is unfolding -- have not helped the cause. Second, as in any research effort being conducted by thousands of scientists across many years and many countries, mistakes will be made in the research or in its collection and reporting. The mistakes that have been revealed recently -- about, most prominently, the likely melting rate of Himalayan glaciers -- need correcting. But in the overall picture, they are trivial.
Politicians nonetheless have seized on both the trivial mistakes and the complexity of the science to cast doubt on the underlying and unrefuted truth of human-caused greenhouse gas accumulation. In many cases, it is hard to know whether they are being obtuse or dishonest, and hard to know which would be worse. To see Virginia's newly elected attorney general join in this know-nothingism is an embarrassment to the state.
What's the right response? It seems to us there are two key arguments that can provide some shelter for politicians who want to do the right thing. The first is to acknowledge a level of uncertainty in the predictions and make the case for taking out an insurance policy, as would any prudent homeowner. It's true that we don't know for sure how many degrees warmer the Earth will be, on average, by 2050 or what effect this will have on the ferocity of storms or coastal flooding or starvation-inducing drought. But it's also true that, as the science has progressed, the predictions have become more dire, not less -- and that they are still as likely to be too optimistic as the reverse. If there is action that can be taken, now, to begin to reduce the dangers, why would we not do so?
The only cogent answer we have heard is that action is hopeless: that wrenching the economy away from its dependence on oil and coal would be so expensive, and the resulting benefit so minimal, that it's not worth trying. Those who make this case in a rational way don't deny the existence of climate change, but they say that the money should be spent instead on mitigation and research into alternative technologies. Our view is that it makes no sense to give up before trying -- especially since measured government action could unleash technological innovation that in turn would make the costs far less than predicted.
And all the more so when -- and this is the second key point -- the action that would have the most beneficial effect with regard to climate change is in the national interest anyway. A gradually rising carbon tax made sense even before "global warming" entered most people's vocabulary. Almost as useful would be a simple cap-and-rebate system that required industry to pay for greenhouse-gas emissions. Either would reduce American dependence on dictators in Saudi Arabia and Venezuela while lowering air pollution of all kinds. Neither would require a complicated government bureaucracy of the kind that has understandably alarmed some people while giving others a pretext for opposition. And if politicians can't bear to stand behind an increased tax, the revenue from either proposal could all be returned in a fair and progressive way.