Quebec had vowed to cut its emissions by 6 per cent compared with 1990 as of 2012. Going further would put the province at the vanguard of the climate-change battle in North America.
"For Quebecers, the environment is synonymous with the future, prosperity and a better quality of life," Charest said in a speech to Quebec business leaders.
On a per-capita basis, the new threshold Charest announced would reduce the province's emissions to eight tonnes. Its previous target was to cut emissions to 11 tonnes per capita, twice the reduction target for Canada as a whole.
Charest said Ottawa needs to do more to reduce Canada's greenhouse emissions. Protecting the environment doesn't mean harming the economy, he said, noting the province's gross domestic product has increased 41 per cent since 1990, even though industry has reduced its emissions by 7 per cent.
"Quebec has the resources, the know-how, the entrepreneurs and the infrastructures to become a symbol in the new green economy."