Annan made the warning in a message to mark the 10th anniversary of the coming into force of Kyoto's parent treaty, the United Nations Framework Convention on Climate Change (UNFCCC).

"Some of [the] effects [of climate change] are by now inevitable and, indeed, we may already be seeing -- in the increased incidence of drought, floods and extreme weather events that many regions are experiencing -- some of the devastation that lies ahead," he said.

Kyoto's "lack of entry into force remains a major hurdle to effective action," the UN secretary general said.

"I call again on those countries that have not yet ratified the Protocol to do so, and show that they are truly committed to shouldering their global responsibilities."

The UNFCCC was the key agreement to emerge from the 1992 Rio Summit, giving birth to a raft of treaties and initiatives aimed at tackling the planet's environmental ills.

The Kyoto Protocol was signed as a framework agreement in 1997 under which rich industrialised countries would curb emissions of "greenhouse" gases -- carbon pollution from the burning of fossil fuels that scientists say is dangerously affecting Earth's fragile climate system.

It took four years to negotiate the Protocol's highly detailed rulebook, but by that time, the United States had quit the process, under a controversial decision by President George W. Bush.

He questioned the scientific evidence for global warming and said Kyoto was both too costly for the US economy, and unfair because the detailed pollution cuts only applied to developed countries.

The US pullout has deprived Kyoto of support from its biggest carbon polluter and left it perilously short of failing to muster enough support to take effect.

Under the Protocol's rules, ratification by Russia is now essential for the deal to become an international treaty. But Russia has been dragging its feet about ratification, notably holding out for further concessions from the European Union (EU), Kyoto's champion.

SPACE.WIRE