Writing in The Globe and Mail, British economist Nicholas Stern warns the clock is ticking on controlling global warming.

An excerpt:

Reducing the risks of climate change is a global challenge but it does require commitment on the national and regional level. In recent months, we have seen positive moves around the world to step up to the plate.

The European Union has strengthened its trading scheme for emissions, and is looking to cut carbon emissions as much as 30 per cent by 2020. China has set a domestic goal to cut energy intensity by 20 per cent by 2010. India is one of the fastest-growing markets for renewable energy in the world. And there have been many moves in the United States, at the federal, state and city level, to tackle the twin challenges of energy security and climate change.

What more should happen now?

Trading in carbon reductions means that action is taken wherever it is cheapest, and it reduces the costs of action around the world. Emerging cap and trade arrangements in the EU, U.S. and elsewhere should not develop in isolation; there are major gains to be realized from the creation of deep, liquid, global markets.

Accelerating development of new low carbon technologies is very important. Here, too, co-operation has real advantages: pooling risk and reward for major infrastructure, increasing the size of markets for cleaner, more efficient products.

Canadians are respected on the global stage for their recognition of the challenge. If Canadians continue to work with Britain, the EU, the U.S. and other partners around the world to create an effective global response to this challenge, there is still time to avoid the worst risks of climate change.

But if we do not act now, the opportunity may not return.

Here's the Stern Review on the Economics of Climate Change.

Here's the CP story on CTV.ca about Stern's day in Canada.