The real climate-change test is moving from words to deeds: View

Bloomberg View

The latest United Nations report on climate change is a collection of previously published findings and grimly familiar statistics. Nonetheless, it raises anew a crucial question: How can we move from admonition to action?

The planet is warming, says the Intergovernmental Panel on Climate Change. Human activity is the dominant cause; the consequences of failing to change this trend will eventually be dire; the costs of addressing the danger aren't great. All this was known. Doing something about it -- that's the hard part, and where most politicians, especially in the U.S., are failing.

The timidity of governments has overtaxed the IPCC and made it ineffective. The panel's synthesis of the science is indispensable and authoritative, but the IPCC is poorly equipped to carry the political burden of changing policy. In fact, it now provides a kind of cover for doing nothing. The endless ministerial wrangling that goes into phrasing its reports is displacement activity. The drafting of documents is no substitute for climate policy.

Expecting the IPCC to play such a prominent role has been harmful in another way: It has shifted attention from common-sense precautions to the impossible quest for scientific certainty. The case for affordable policies to reduce climate change doesn't require scientific certainty; it's a matter of prudently insuring against risk. Choosing the precautions that strike the best balance between costs and benefits while spreading the burden fairly is fundamentally a political task.

Rather than dwelling on scenarios of planetary disaster that put distant generations in jeopardy (a mode of thinking that puts short-sighted democracies at a disadvantage), policy makers ought to look harder for low-cost actions that make sense -- and are seen to make sense -- immediately.

Shifting from coal-fired power generation to renewable sources of energy, for instance, reduces emissions of particulates as well as carbon, with fast-acting health benefits. Supporting research into cheap solar power and complementary battery technologies would advance other kinds of profitable innovation, as well as curb greenhouse gases. Many humdrum carbon-reducing technologies already make economic sense regardless of climate change, because they save money. Such opportunities should be encouraged and exploited wherever possible.

Consumers can play their part by voting with their paychecks -- spending on fuel-efficient cars, for example, or more effective home insulation. Businesses can invest the same way. In many industries, they've already started. Cities can take the initiative, too -- the more that do, the better.

Taken together, all this can go a long way. Yet there is no substitute for a national and even global strategy. Long-lived investments have to be planned years ahead. A guiding framework for longer-term policy is needed as well, which is where carbon taxes come in. The carbon-tax approach gives producers a clearer idea of what to expect. The result would be smarter investment and, other things being equal, faster growth. In addition, smart international coordination (which effective climate policy requires) would be easier.

Better still, a carbon tax collects revenue that can be used to cut other taxes. In most countries, taxes that twist incentives in seriously growth-reducing ways aren't hard to find; a deftly paced switch to carbon taxes could reduce the losses caused by those dumber taxes. Again, it makes sense regardless.

Governments shouldn't need yet another new IPCC report to get them to change their policies. The science may not be settled, but it's clear enough to warrant action, and it has been for years. The deficit now is in political leadership.