WASHINGTON, Sept. 20 (Xinhua) -- Hundreds of top scientists on Tuesday published an open letter warning against claims by Republican presidential nominee Donald Trump that if elected he would advocate U.S. withdrawal from the 2015 Paris Accord on climate change.
"Human-caused climate change is not a belief, a hoax, or a conspiracy. It is a physical reality," said the letter, signed by 375 members of the U.S. National Academy of Sciences, including 30 Nobel laureates and renowned scientists such as Stephen Hawking.
The U.S. withdrawal would "send a clear signal to the rest of the world: 'The United States does not care about the global problem of human-caused climate change,'" they warned.
The letter also said the consequences of opting out of the Paris agreement would be severe and long-lasting for our planet's climate and for the international credibility of the United States.
"The United States can and must be a major player in developing innovative solutions to the problem of reducing emissions of greenhouse gases," it wrote.
"Walking away from Paris makes it less likely that the U.S. will have a global leadership role, politically, economically, or morally. We cannot afford to cross that tipping point."
Trump has called climate change "a hoax" and said the Paris Accord was "bad for U.S. business."
"We're going to cancel the Paris climate agreement and stop all payments of U.S. tax dollars to U.N. global warming programs," he said in a speech on May 26 this year.