JAKARTA, Indonesia — Secretary of State John Kerry on Sunday called climate change perhaps the world’s most fearsome weapon of mass destruction and mocked those who deny its existence or question its causes, comparing them to people who insist the Earth is flat.
Mr. Kerry painted a picture of looming drought and famine, massive floods, and deadly storms as a result of climate change.
He urged ordinary citizens in developing nations to speak out on the issue and demand more from their political leaders and labeled those who denied the evidence of climate change as “shoddy scientists and extreme ideologues.”
The secretary of State was addressing students and government officials in the Indonesian capital, Jakarta, in a country and region that he said are “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.
Though 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 Mr. Kerry, who has spent much of his political career calling for more action on the issue, said that every country needs to play a role in cleaner energy or the world would face a calamitous future.
He called 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 biggest sources of emissions of carbon dioxide and other gases that cause the atmosphere to trap solar heat and alter the climate. Scientists say such changes are leading to drought, wildfires, rising sea levels, melting polar ice, plant and animal extinctions, and other extreme conditions.
On Saturday, the United States and China announced an agreement to cooperate more closely on combating climate change. American officials hope that will help encourage others, including developing countries like Indonesia and India, to follow suit.
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 climate change.
Mr. Kerry said scientists predict that melting ice caps could raise sea levels 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, Mr. Kerry said.
Mr. 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.
“The science is unequivocal, and those who refuse to believe it are simply burying their heads in the sand,” he 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.”