Addressing a group of students and government officials at an American cultural center in the Indonesian capital of Jakarta, Secretary of State John Kerry called climate change perhaps the world’s most fearsome weapon of mass destruction. (U.S. Department of State)

Secretary of State John F. Kerry, calling climate change perhaps the world’s most fearsome weapon of mass destruction, urged developing nations on Sunday to do more to cut greenhouse-gas emissions as he derided climate-change skeptics at home and blamed big companies for hijacking the debate.

Kerry painted a picture of looming drought and famine, massive floods and deadly storms as a result of global warming, and he urged ordinary citizens in developing nations to speak out on the issue and demand more from their political leaders. He labeled those who denied the evidence of climate change as “shoddy scientists and extreme ideologues.”

He was addressing a group of students and government officials at an American cultural center in the Indonesian capital, Jakarta, in a country and region that he said were “on the front lines of climate change” and some of the most vulnerable to the effects of global warming. “It’s not an exaggeration to say that the entire way of life here is at risk,” he said.

Global efforts to counter climate change have long foundered on a sharp divide between developed and developing nations. Although developing nations now account for more than half of greenhouse-gas emissions, they have been reluctant to commit to meaningful cuts as they seek a path to Western industrialization and prosperity. They argue the West caused the problem and should fix it.

But Kerry, who has spent much of his long political career calling for more action on the issue, said that every country needed to play a role in cleaner energy or the world would face a calamitous future, calling climate change “perhaps the world’s most fearsome weapon of mass destruction.”

“It’s absolutely true that industrialized countries have to play a leading role in reducing emissions, but that doesn’t mean other nations have the right to repeat the mistakes of the past. It’s not enough for one country or even a few countries to reduce emissions when other countries continue to fill the atmosphere with carbon pollution as they see fit,” he said.

“If even one or two major economies neglects to respond to this threat, it will counteract all of the good work that the rest of the world does. When I say we need a global solution, I mean we need a global solution.”

China and the United States are the world’s largest sources of greenhouse-gas emissions, accounting for about 40 percent. Indonesia, a country of around 240 million people, is in the top 10 sources of carbon emissions globally, largely as a result of deforestation, and is also a major coal exporter. But like many developing nations, Indonesia, an archipelago of some 17,000 islands, has a lot to lose from global warming.

Kerry said scientists predicted that melting ice caps could push sea levels up by more than three feet by the end of the century, putting half of Jakarta underwater and displacing hundreds of millions of people worldwide.

Changes in ocean temperatures and acidification of the seas could also reduce fish catches in Indonesia by as much as 40 percent, he said, while typhoons such as the one that struck the Philippines last year could become the norm and “wipe out entire communities.”

There was still time to act to address the problem, but the window was closing, Kerry said. The problem was not finding a scientific solution, but a lack of political resolve.

“Today, I call on all of you here in Indonesia and concerned citizens around the world to demand that resolve from your leaders. Speak out. Make climate change an issue that no public official can ignore another day. “

A similar call to arms in a speech in India last year failed to have any impact, but Kerry said he would be telling U.S. diplomats all over the world to make climate change a priority from now on.

Kerry spent a considerable portion of his speech spelling out the scientific consensus behind climate change, which he said was almost as conclusive as the gravity that caused an apple to fall from a tree or the laws of thermodynamics that meant your hand would burn when touching a hot stove. Ninety-seven percent of the world’s scientists agree that the climate was heating fast up as a result of human activity, he said, and the world needed to listen — and act.

“We simply don’t have time to let a few loud interest groups hijack the climate conversation,” he said, blaming big companies that “don’t want to change and spend a lot of money” to stop people acting to reduce the risks.

“First and foremost, we should not allow a tiny minority of shoddy scientists and extreme ideologues to compete with scientific facts,” Kerry told the audience. “Nor should we allow any room for those who think that the costs associated with doing the right thing outweigh the benefits.”

“The science is unequivocal, and those who refuse to believe it are simply burying their heads in the sand,” Kerry said. “President Obama and I both believe we don’t have time for a meeting anywhere of the Flat Earth Society.”

Eight of the 10 hottest years on record have all happened within the past decade, he said. “Or think about this way: All 10 of the hottest years on record have actually happened since Google went online in 1998.”

Kerry arrived in Indonesia from China, where he secured a commitment from the leadership to liaise more closely with Washington on the issue. “I’m pleased to tell you China agrees with the United States that it’s time to pursue a cleaner path forward,” he told the audience.

The United States and China have traditionally been on opposing sides of the table in global climate-change talks. The hope is that the message that the two are now talking less confrontationally about the issue will also encourage other major developing nations such as India, Indonesia and Brazil to treat the problem more seriously.

“Given China and the United States are the two biggest emitters, there is no question that continued coordination on climate change sends a strong message to the world that this an issue we need to address now,” said a senior State Department official who was not authorized to speak on the record.

But the Obama administration’s credibility, and Kerry’s own personal credibility, on the issue of climate change face a severe test in coming months, as they have to decide whether to give the go-ahead to a $5.4 billion Keystone XL oil pipeline to bring Canadian crude oil to U.S. refineries.

The State Department’s own environmental assessment of the project concluded last month that the project would not significantly add to greenhouse-gas emissions, but environmentalists disagree, and some argue that approval would shred Obama’s claim to be a global leader on climate change.