HONG KONG (AFP) - Global governments must dig deep to combat climate change, the World Bank chief said Thursday, describing it as a "fundamental threat" to development.

Kim Jim Yong warned that governments "must act now" to limit global warming and finance policies that favour sustainable development, otherwise the impact would be "devastating".

"Climate change is a fundamental threat to development in our lifetime," Kim said in a video address to an environment conference in Hong Kong hosted by the Potsdam Institute for Climate Impact Research - the first time the meeting has been held in Asia.

"This is the year when the international community can and must find ways to finance climate change interventions and development," he said.

Kim warned of risks in Asia and the vulnerability of mega cities, which are prevalent in the region.

"Sea-level rise of 15 centimetres coupled with more intense cyclones threatens to inundate much of Bangkok by the 2030s," he said, reiterating research by the Potsdam Institute.

Kim added that the World Bank was working with China, which has overtaken the US as the greatest greenhouse emitter, and other governments in developing countries to promote sustainable growth.

"We can choose to build smart cities and require strong energy efficiency standards. We can invest in rapid transit systems and we can expand use of low carbon energy sources," he said.

The Nobel Laureates Symposium on Global Sustainability has previously been held in Europe and brings together experts and prize-winning scientists.

Japan's Ryoji Noyori, recipient of the Nobel Prize for Chemistry in 2001, used his own country to illustrate how climate change could be disastrous.

"Japan has many coastal cities... in danger of floods. But unfortunately, the government has not done enough in counter measures," he said.

Governments in Asia should learn from past mistakes by nations that are now developed, said Hans Joachim Schellnhuber, the director of the Potsdam Institute.

"Asia has a choice. We simply do not need to imitate the old way... 200 years of dirty development." But Hong Kong leader Leung Chun Ying said it was "easier said than done" to take on environmental issues.

He defended the city's record on development, despite growing public concerns over pollution.

"Hong Kong attaches great importance to combating climate change... This is, of course, easier said than realised. But I am pleased to say that we are on track to achieving it," he said in the opening address at the symposium Thursday.