Just as future generations are entitled to live in a prosperous economy, so too do they deserve to see real action to fight "the growing menace of climate change," Prime Minister Stephen Harper told APEC delegates in Australia Friday morning.

Harper delivered his environment-themed address in Sydney, reminding business leaders attending the Asia-Pacific Economic Co-operation forum that while stimulating economies should be a key priority, that goal must be balanced "with careful environmental stewardship."

For at least a decade, Canada's own government merely paid "lip service" to the issue, the prime minister said, in a swipe at the former Liberal government's environmental record.

But it took some time for Harper himself to warm to the scientific evidence of global warming. A former skeptic, Harper's speech at the Sydney Opera House signalled an apparent shift, as he characterized Canada on Friday as a future champion or "world leader in the fight" against climate change.

"The weight of scientific evidence holds that our atmosphere is getting hotter, that human activity is a significant contributor," Harper said. "There will be serious consequences for all life on earth."

The prime minister pledged at the APEC business summit that Canada will reduce its greenhouse gas emissions by 20 per cent by 2020, relative to 2006 emission levels.

"Our government's actions are guided by a balanced approach to environmental protection and economic growth," Harper said.

Harper to meet New Zealand PM

While in Opposition, Harper balked at the former Liberal government's agreement to strict greenhouse gas emission targets under the Kyoto Protocol. Canada never came close to meeting those targets, and in fact, some emissions rose significantly from 1990 levels, the benchmark for the Kyoto agreement.

Harper said Friday that the past government's green plans were all "political rhetoric" without any real action.

Harper's speech came amid reports that the 21 APEC members have failed to agree to emissions targets for the final summit communiqué, which remains under wraps.

The main leaders summit in Sydney gets underway Saturday and wraps up Sunday, although a series of high-level bilateral meetings between the major APEC players has been underway for the past 48 hours.

Harper was to hold meetings later Friday with New Zealand Prime Minister Helen Clark and Peruvian President Alan Garcia.

With files from the Canadian Press