President Trump has already told close friends and confidants of his plans to withdraw from the climate deal, and he has also discussed with senior White House staff attempting to renegotiate the Paris climate protocols on reducing greenhouse gas emissions - with an eye to making them less onerous to USA industry.
Another option, said University of California, Berkeley climate scientist Zeke Hausfather, would be for Trump to withdraw from the United Nations Framework Convention on Climate Change, the treaty on which the Paris accord was based, which would take only a year.
The United States, under former President Barack Obama, had committed to reduce its emissions by 26 percent to 28 percent from 2005 levels by 2025. The administrator of the EPA, Scott Pruitt, was working on details.
Pulling out of the agreement outright would take three-and-a-half years under the standard cooling-off period for new worldwide treaties.
As one of the largest emitters of carbon dioxide in the world, a United States withdrawal would represent a major blow to a deal that seeks to limit the worst effects of climate change. Beijing, however, has reaffirmed its commitment to meeting its targets under the Paris accord, recently canceling construction of about 100 coal-fired power plants and investing billions in massive wind and solar projects.
Canada, the European Union, and China have said they will honor their commitments to the pact even if the United States withdraws. That promise helped rally supporters sharing his skepticism of global efforts to police United States carbon emissions.
The Vatican, which under Pope Francis' insistence has strongly backed the Paris accord, would see a USA exit as a "a huge slap in the face", a senior Vatican official said on Thursday. He also had to navigate a split among his advisers.
Trump met Wednesday with Secretary of State Rex Tillerson, who has favoured remaining in the agreement.
"So we're getting out but we will start to negotiate and we will see if we can make a deal that's fair", Trump said.
Mr Musk's move, announced on Twitter, could deepen the rift between the tech world and the Trump administration, which have been at odds over immigration and other issues.
The ad ran earlier this month but has been renewed because of the news of Trump's thinking on the Paris deal, reports Politico.
The Agreement also provides for an enhanced transparency framework for action and support.
Several Democrats have spoken out against the "misguided" step saying it could potentially damage not only the environment, but also the economy.
Trump also has expressed doubts about climate change, at times calling it a hoax to weaken US industry.
German Chancellor Angela Merkel, who has in the past even been dubbed the "climate chancellor" for her efforts to fight global warming, welcomed Li's remarks at their joint press conference.
"If they decide to pull out it would be disappointing but I really do not think this would change the course of mankind", said European Commission Vice President Maros Sefcovic.
In this weird world that we now live in, China is being held up by many as the world's leader in globalism and environmental protection.