Leading physicist Stephen Hawking has slammed President Donald Trump's environmental policy and called for the ousting of Environmental Protection Agency chief Scott Pruitt.

Hawking is a recipient of the prestigious U.S. Franklin medal for science and winner of the presidential Medal of Freedom from Barack Obama and spoke out his concerns over "definite swing to a right-wing, more authoritarian approach."

"He should replace Scott Pruitt at the Environment Protection Agency," Hawking said and noted that climate change is an unstoppable danger.

"It affects America badly, so tackling it should win votes for his second term. God forbid."

Unwelcome Guest In Trump's America

Commenting on a question whether he would visit the United States, Hawking said he may not be welcome under President Trump.

"I would like to visit again and to talk to other scientists, but I fear that I may not be welcome," he said in an interview.

In the past, Hawking had called Trump a demagogue.

"Trump was elected by people who felt disenfranchised by the governing elite in a revolt against globalization," he said in Good Morning Britain.

According to Hawking, Trump's priority seems to be satisfying his electorate who is neither liberal nor well informed.

Commenting on the discovery of TRAPPIST-1 exoplanets comprising seven Earth-sized planets 39 light-years away, Hawking said the current technology does not allow humans to travel that far.

Hawking said the best way to explore them will be sending a robotic nanocraft propelled by giant lasers with 20 percent speed of light. They may take at least 240 years to reach the destination and send pictures back.

"It is feasible and is something that I am very excited about," Hawking added.

Hawking Confirms Space Journey

Meanwhile, Hawking revealed that he has given his nod for a space journey on board Richard Branson's spaceship and never dreamed of a space journey.

"Richard Branson has offered me a seat on Virgin Galactic, and I said yes immediately," he said. Branson's spaceship named Virgin Galactic hopes to carry people into space on commercial missions.

US Military Calls Climate Change A Security Threat

Meanwhile, in a testimony, U.S. Defense Secretary James Mattis told a Senate panel that climate change is a serious threat to national security. This differs from the stand of Trump administration that has been playing down the threats of climate change.

The statement is an indication that the assessment of military leadership is at variance with President Trump and his close followers.

Mattis referred to the threat from global warming and matters such as open-water routes at the mellowing Arctic and drought in global trouble spots as fallout. These are distinct military threats and need to be tackled as such.

"Climate change is impacting stability in areas of the world where our troops are operating today," Mattis said in written answers.

In a report back in 2015, Pentagon had painted climate change as a security risk that will accentuate world problems such as "poverty, social tensions, environmental degradation, ineffectual leadership and weak political institutions that threaten stability in a number of countries."

ⓒ 2018 TECHTIMES.com All rights reserved. Do not reproduce without permission.