Speaking at the 2007 International Conference on Climate Change, Tsang described global warming as one of the most important challenges facing our planet.

"It is up to each and every one of us to make the right choices, even if it means changing life-long habits when it comes to consuming," he stressed.

He outlined several measures Hong Kong is taking to tackle the problem, including encouraging the two local power companies to switch to cleaner fuels by linking their permitted rates of return to the achievement of emission reductions when their schemes of control are renewed next year, setting a target of 1 percent to 2 percent of our total electricity supply to come from renewable sources by 2012, and using methane gas at landfills as fuel.

The vast majority of Hong Kong citizens are willing participants, he said, and it often requires only a gentle reminder or a nudge in the right direction.

"Our Action Blue Sky Campaign does just that. To give one example, it urges people to keep their air conditioners at 25.5 degrees centigrade during summer months, which is a simple act that can save 1 billion units of electricity and reduce our greenhouse gas emissions by 700,000 tons a year," he said.

"The government has also taken the lead by encouraging people to dress more casually in the hotter summer months so that they might not feel the need to twist the air conditioning knob a few degrees cooler," he added.

Tsang stressed combating climate change will only be successful if we all face up to our responsibilities, adding governments, big business, non-governmental organizations and individual citizens all have a significant role to play.

"Hong Kong prides itself on being a world city. We flourish on international trade, and firmly believe that continued economic growth can only be achieved if we protect the environment that sustains us. Protecting against global warming must be a team effort, spearheaded by the strongest and wealthiest nations, protecting and guiding the most vulnerable regions, and above all ensuring an environment for our future generations to enjoy and in which they can continue to thrive," Tsang said.