The UN climate change conference opens in Copenhagen today, giving humankind a much-needed chance to define its growth model, as well as its future.

True, there is expectation of achieving only a political agreement. But if negotiators both from rich and poor countries demonstrate enough resolution and flexibility in their talks, a Copenhagen deal could well mark the end of the beginning of the global fight against climate change.

Though die-hard climate-change skeptics still refuse to recognize the threats posed by global warming, the Copenhagen summit itself is proof of the growing agreement among politicians, scientists, businessmen and ordinary people on its seriousness.

A successful global deal on climate change must make clear that Copenhagen is only part of a process, not its final destination.

More importantly, world policymakers should defy the pessimism fuelled by a combination of global recession and lack of political will to facilitate collective and concrete action in cutting greenhouse gas (GHG) emissions.

Admittedly, rich and poor countries are still widely divided on how to share the cost of action. While the developed countries have been pumping GHGs into the atmosphere for 200 years (which comprise most of the GHGs in orbit), their emission-cut targets and offer of financial aid and technology transfer to the developing countries are far from satisfactory.

But this rich-poor world rift should not be allowed to obstruct the two-week Copenhagen talks to agree on a new global climate deal to succeed the Kyoto Protocol in 2013.

Without concerted and adequate action, our planet may soon be on the trajectory of an irreversible journey toward a future where most of the plant and animal species would become extinct, making it even more difficult for humans to survive.

Yet if we take joint action at the global, national, local and personal levels, humankind could find a low-carbon development path that makes economic growth compatible with environmental development. Global leaders should work together to convince their peoples that climate change poses a threat, but it offers opportunities, too.

It is not clear exactly how long it will take for the world economy to shift from carbon-intensive growth to low-carbon development. But it is crystal clear that if that change is to happen, it should start now.

Let us hope the Copenhagen conference is successful, for it will not only give a fresh boost to global awareness on climate change, but also usher in a new chapter in building a low-carbon future.