Nations, businesses and Washington's top diplomat urged president-elect Donald Trump on Wednesday not to withdraw the US from the climate-rescue Paris Agreement and its commitments to preserve Earth for future generations.

US Secretary of State John Kerry underlined the perils that await the world if leaders drag their feet on cutting planet-warming greenhouse gases, while poor nations and small-island states highlighted their own vulnerability to the predicted climate catastrophe.

"At some point even the strongest sceptic has to acknowledge that something disturbing is happening," Kerry said at a UN climate conference in Marrakesh, just a week after Trump's election to the White House.

Before his election, the business tycoon called climate change a "hoax" perpetrated by China and vowed to "cancel" the hard-fought Paris Agreement concluded last year to limit dangerous global warming.

The Marrakesh meeting has started to draft a roadmap for putting the agreement's goals into action, but many fear a Trump administration would destroy political momentum built up over years of tough negotiations, imperilling the very goals of the global pact.

Kerry stressed Wednesday that "climate change should not be a partisan issue".

"No one has the right to make decisions affecting billions of people based solely on ideology without proper input," he added.

Major companies joined the chorus, calling for "continuation of low-carbon policies" and investment in a low-carbon economy.

"We call on our elected US leaders to strongly support... continued US participation in the Paris Agreement," said an open letter signed by more than 360 companies and investors, mainly American, including a dozen Fortune 500 firms.

The Paris pact sets the goal of limiting average global warming to 2.0 degrees Celsius (3.6 degrees Fahrenheit) over pre-Industrial Revolution levels, by cutting greenhouse gases from burning fossil fuels.

Countries, including the United States, have pledged to curb emissions under the deal by moving to renewable energy sources.

But Trump has vowed to boost oil, gas and coal.

"Time is not on our side," warned Kerry, who has made the fight against global warming a hallmark of his tenure.

- Increasingly alarming -

"The world is already changing at an increasingly alarming rate with increasingly alarming consequences."

Thoriq Ibrahim, environment minister of the Maldives, said the time for action was running out "especially for small island states whose very existence is threatened by powerful storms, poisoned oceans, and rising seas".

"And now politics has entered the discussion in a way that has again put our ultimate success in doubt," he said.

"Indeed, we can understand the concern and frustration expressed by so many here and around the world that worry what the future may hold."

Frederick Mitchell, foreign minister of The Bahamas, compared climate scepticism to the church's persecution of 17th century Italian astronomer Galileo Galilei for stating that the Earth revolved around the Sun.

For those doubting climate scientists today, "there will be no comfort in 2050 if the scientists are then proven right," he said. "It will be too late for the sceptics to say sorry."

Analysts say that on current emissions-curbing pledges, the world is headed for warming of about 3 C -- with land-gobbling sea level rise, worsening storms and droughts, disease spread, and conflict over ever-scarcer resources the result.

While waiting for the new president to make his climate position clear, many now look to the rest of the world to bolster the Paris Agreement.

At a ministerial-level gathering Wednesday, speaker after speaker, from Africa, South America, Russia, Asia and Europe, recommitted their nations to the pact.

"We must honour commitments and consolidate mutual trust," said China's climate envoy Xie Zhenhua.

Kerry said Washington was well on its way to meeting targets under the Paris pact, and "I do not believe that that can or will be reversed."

Market forces, not politics, will dictate the world's energy future, the diplomat added.

"That's why I'm confident for the future regardless of what policy might be chosen, because of the marketplace."

While Trump's ascension to the US presidency has been uppermost on the minds of delegates in Marrakesh, diplomats have been pushing on with the nuts-and-bolts work of designing rules and procedures for the Paris Agreement's execution.

And ministers met on Wednesday to discuss the hot-button issue of finance for staving off dangerous climate change.