Hundreds of highly-regarded scientists, including famed physicist Stephen Hawking, signed a letter blasting Republican presidential nominee Donald Trump for saying he would "cancel" the United States' participation in the Paris climate deal because there's no clear evidence climate change exists.
“Human-caused climate change is not a belief, a hoax, or a conspiracy. It is a physical reality,” states the letter, published on Responsible Scientists' website, before going on to explain how climate change works and how humans are causing it to happen, which is leading to disastrous consequences around the world.
"It is of great concern that the Republican nominee for President has advocated U.S. withdrawal from the Paris Accord,” the letter continues. “A 'Parexit' would send a clear signal to the rest of the world: 'The United States does not care about the global problems of human-caused climate change. You are on your own.'"
In addition to Hawking, other notable names include Nobel Prize-winning physicist Stephen Chu, who served as President Barack Obama's Energy Secretary between 2009 and 2013.
In his farewell letter to Energy Department employees, Chu warned that climate change is caused by humans.
“The overwhelming scientific consensus is that human activity has had a significant and likely dominant role in climate change,” he wrote. “There is also increasingly compelling evidence that the weather changes we have witnessed during this thirty year time period are due to climate change.”
In May, Trump gave a speech on his energy policy and vowed to exit the Paris climate deal, which has been signed into by nearly 200 countries to reduce carbon emissions.
Rather than adhering to the deal, Trump said he would advocate for increased oil drilling and fewer regulations.
"Any regulation that's outdated, unnecessary, bad for workers or contrary to the national interest will be scrapped and scrapped completely," he said, according to BBC. "We're going to do all this while taking proper regard for rational environmental concerns."