SINGAPORE - Jubilation over the Paris climate talks last year now needs to be channeled into concrete action.

This was the call of Singapore's chief negotiator for climate change Kwok Fook Seng at a public forum organised by the National University of Singapore's (NUS) Tembusu College on Tuesday (March 22).

"No country has any excuse not to act anymore," Mr Kwok said. "189 countries have voluntarily pledged their action; that covers 99 per cent of global emissions as we stand today."

The Paris agreement must be ratified by at least 55 countries representing at least 55 percent of global greenhouse gas emissions to enter into force.

It sets a collective goal of keeping global warming below 2 deg C, compared to pre-industrial times, and to pursue efforts to limit the temperature rise to 1.5 deg C.

The pact requires all countries to submit plans for climate action and to update them every five years, though such plans are not legally binding.

French ambassador to Singapore, Mr Benjamin Dubertret, said that last year's meeting of the United Nations Framework Convention on Climate Change in Paris was only the beginning of a journey, and stressed the importance of getting the younger generation to act on climate change.

He said to the NUS students who comprised the majority of the 260 attendees: "You will bring in fresh views on what has already been a relatively old problem we are only starting to solve."

Mr Dubertret called the Paris agreement a "turning point", attributing its succes to the atmosphere of transparency and to the informal discussions among countries to identify possible compromises prior to the meeting.

The Paris agreement is not without its critics. In earlier reports, Dr James Hansen, a former Nasa scientist regarded as the father of climate change awareness, has criticised the agreement as "no action, just promises".