There is a "frightening lack of leadership" on climate change and an urgent need for more effort to avoid major consequences, the UN's secretary general told an international meeting Wednesday.

"Climate change is not just an environmental issue, as too many people still believe. It is an all-encompassing threat," Kofi Annan said in Nairobi, Kenya.

Speaking at the UN Framework Convention on Climate Change, Annan said global warming should be tackled on the same scale as war, poverty and the buildup of weapons. "While the Kyoto Protocol is a crucial step forward, that step is far too small. And as we consider how to go further still, there remains a frightening lack of leadership," he said.

Delegates to the 12-day conference, which has attracted 165 countries and ends Friday, are discussing ways to reduce greenhouse gas emissions after 2012, when the Kyoto Protocol expires. The U.S. and Australia are the only major industrialized countries to reject the 1997 Kyoto accord, which calls for mandatory cuts in greenhouse gases.

Annan also announced a UN plan to help Africa get funding for clean development projects, such as wind power and renewable energy.

Canada's environment minister, Rona Ambrose, is expected to speak on Wednesday.

Ambrose has been criticized for the Canadian government's new environmental position - a focus on clean air and smog reduction rather than the wider problem of climate change.

But after arriving on Tuesday, she told reporters there is "no bad guy" on climate change. Delegates from around the world are at the meeting to engage in serious talks, and all efforts should be encouraged, she added.

"They're all here to make progress. It's really important to start talking about inclusivity."

In a news conference on Monday, Canadian opposition parties and environmental groups said the Harper government's position does not reflect the concerns of many Canadians.

Canada and Australia were cited by an environmental group, the Climate Action Network, as having contributed the least to progress during the talks, receiving the group's Fossil of the Day award.

The Harper government's proposed clean air act, introduced in October, aims to cut greenhouse gas emissions by between 45 and 65 per cent from 2003 levels by 2050.

Under Kyoto, however, Canada agreed to reduce emissions to six per cent below 1990 levels between 2008 and 2012, and Prime Minister Stephen Harper has indicated Canada will not likely meet those targets.

The conference is the second meeting of the Kyoto-backed countries, and the first UN climate summit in sub-Saharan Africa.