Greener building practices could cut North America's greenhouse gas emissions more effectively than any other available measure. Canada, Mexico and the US are being urged to embrace greener construction methods That is the conclusion of a new report from the Commission for Environmental Co-operation (CEC). Green Building in North America: Opportunities and Challenges says buildings release about 35% of the continent's total CO2 emissions and this could be the quickest and cheapest way to reduce North America's impact on climate change. The CEC, an organisation established by Canada, Mexico and the US to examine environmental issues affecting the three nations, said rapid uptake of existing and emerging energy-saving technologies could save 1,700 megatons of CO2 in 2030. This is almost equivalent to the amount of carbon dioxide emitted by the entire US transport sector in 2000. Green building currently only accounts for 2% of the new non-residential building market in North America, less than 0.5% of the residential market in the US and Canada, and even less in Mexico. "Improving our built environment is probably the single greatest opportunity to protect and enhance the natural environment," said Adri