12/14/2010 02:21 pm ET Updated May 25, 2011

Cancún Summit No Solution to Global Warming

There are basically two ways to cut carbon emissions, and neither one of them involves global climate change summits like the one just held in Cancún, Mexico. The way I see it, you can either price carbon, or you can restrict growth.

As they did for the previous meeting in Copenhagen, some 200 of the world's economies came together and did absolutely nothing to halt their global carbon emissions, other than to commit to long-range targets with expiry dates set for a time when most current delegates will no longer be in public office or, for that matter, even be alive.

Economics furnishes a handy remedy to this -- put a price on carbon emissions or tax the energy consumption that generates emissions so that emitters will have to pay the costs we'll all ultimately have to bear as a result of climate change. But for carbon pricing to work, there has to be one global price, and it must be applied universally. Otherwise, emissions will simply migrate to the countries where there are the fewest deterrents.

The US, along with other developed economies like Japan and Canada, argues that it won't make its industries or consumers pay for carbon emissions if other countries (like China, the world's largest emitter) don't do the same.

China responds that climate change doesn't reflect only today's emissions but summarizes cumulative emissions from over the last 250 years of global industrialization. On a cumulative basis, calculated since 1751, China's emissions are still roughly only one third of the US's.

Nevertheless, it's the emissions from the rapidly expanding and largely coal-powered Chinese and Indian economies of today that threaten to push current atmospheric CO2 levels over some climatic tipping point.

China counters that its emissions, on a per capita basis, are only one tenth of North America's. Following this logic, China should be entitled to emit more in order to industrialize sufficiently so that it can emancipate hundreds of millions of its citizens from economic poverty.

China sees attempts to control the growth of its emissions as efforts to limit its rate of economic growth, which in turn reduces the number of people that can be brought out of poverty. But is China's plan to give hundreds of millions of its rural citizens first-world energy consumption levels ecologically sustainable, or, for that matter, even economically possible, given where oil prices are already trading?

In the absence of carbon pricing, there is one sure-fire way to cap emissions, and that's to cap growth. What no one wants to acknowledge at the Cancún summit is that economic downturns are bullish for the environment. For example, in the economic chaos that followed the collapse of the Soviet Union, the country's energy consumption (and emissions) fell by nearly 30 per cent. During the recent recession, global CO2 emissions fell without any government mandate to that effect and without any meaningful price on carbon emissions.

If the world is serious about tackling global climate change, we need to put a meaningful price ($50-$60 per metric tonne) on carbon emissions now. If we don't, our next choice is to forego economic growth.