Their View | U.N. climate summit can show what cities have accomplished

The following editorial appears on Bloomberg View:

It’s tempting to dismiss the United Nations climate summit that starts Tuesday in New York as nothing but an occasion for meetings, marching and platitudes. There’ll be plenty of each, no doubt — to say nothing of Leonardo DiCaprio’s speech as U.N. messenger for peace on climate change, a treat for cynics of all nationalities. Despite all that, the gathering of 125 world leaders isn’t a waste of time.

A purpose is to highlight efforts to cut greenhouse-gas emissions and demonstrate progress is feasible, affordable and happening. Because the need to build political support for stronger action is paramount, that’s a crucial message.

Resistance to stronger measures on climate change is driven partly by the fear that they’d be prohibitively expensive and set back economic growth. Intelligent action, on the contrary, is affordable and isn’t anti-growth. In due course, a formally coordinated international program is likely to be necessary, and the U.N. hopes to reach agreement on that larger ambition during talks next year in Paris. For now, building support for action by seeking out best practices and demonstrating their practicality is all to the good.

Governments attending the summit intend to announce new commitments on carbon emissions and new measures to support those commitments — including investments in renewable energy, public transit and more resilient infrastructure.

Companies will use the summit as well, to announce changes in the way they do business to serve the same goal. For example, almost 30 companies are expected to agree to apply an internal carbon price to their operations and investment decisions.

A prime focus will be cities, which produce 70 percent of global greenhouse-gas emissions. Many have targets for cutting them and have announced specific measures. In some cases, they’re aiming to improve on the targets set by their respective national governments.

The point isn’t to reduce the costs of carbon pollution in their neighborhoods: A ton of carbon released in one place does the same harm to the planet, climate-wise, as a ton released anywhere else. Rather, it’s to show that stronger measures are no great burden. Cities can take them in stride.

Another theme will be to review the mounting evidence that failing to act involves costs today, as well as risks tomorrow and beyond. The effects of global warming are already reducing output and imposing costs in public health and safety. This burden is likely to increase in future.

You don’t need certainty about those future effects to know that insuring against the danger, intelligently and at moderate cost, makes sense. Several countries, for instance, have used carbon taxes to good effect — showing that this policy can successfully reduce emissions without imposing a burden on the economy or causing any of the other problems that critics assert.

Paying attention to what works is always worthwhile.