Yesterday, the British Columbia government announced that it is joining 5 western states in an international carbon trading market designed to tackle global warming and aggressively reduce greenhouse gases.

BC joins California, New Mexico, Oregon, Washington and Arizona in a growing partnership that now includes close to 60 million people. In the next few days, several Australian states are also expected to join, and Governor Schwarzenegger hopes to recruit at least four or five more Canadian provinces in the coming months.

Critics of the plan note that BC has promised to join such efforts in the past, but has failed to follow through because there were no hard caps on greenhouse gas emissions. To date, California has legislated hard caps under law. BC has not.

Mark Jaccard, Simon Fraser University's internationally respected global-warming expert, noted that B.C. politicians declared their support for a similar carbon trading system about 15 years ago. It quickly foundered because the New Democratic Party government never took the tough step of actually capping greenhouse gas emissions, meaning there was never a real incentive to buy carbon credits.

"We've already had governments make these announcements, but then they never come through with the greenhouse gas caps," said Jaccard. "In the absence of the government setting caps that are serious, an announcement of a trading system is meaningless.

BC's announcement follows up February's crown speech which stated that the province would reduce greenhouse gas emissions 33% by the year 2020.