TRUMP 'CANCELS' PARIS CLIMATE AGREEMENT

President Donald Trump was set to announce Thursday that he was pulling the US out of the landmark Paris climate agreement, following through with a key campaign promise, multiple sources reported on Thursday.

While the decision should galvanize his base, the move goes against what some of the largest American companies, and many in the rest of the world were hoping for.

The Paris agreement, which 195 nations signed in December 2015, set the global goal to keep the planet from warming by more than 1.5 degrees Celsius above preindustrial levels - a threshold that scientists say could keep the planet from launching into a tailspin of irreversible consequences, from unpredictable superstorms to crippling heat waves.

China, India, and the European Union all doubled down on their support of the deal, and said they would lead the world in fighting climate change if the United States wouldn't. Experts warn that the US's exit could lead to a crippled agreement, either via other countries deciding to leave or not honestly reporting their carbon emissions.

Trump's desire to put "America First" on climate could be seen in the rest of the world as the US "turning its back on the international community."

'International condemnation'

Scientists say the US's weakening climate response could slow down global efforts to combat the problem.

While the US today is the second biggest carbon emitter after China, it has contributed to the most emissions over time, accounting for roughly a third of the excess, warming carbon in the atmosphere today.

Elliot Diringer, executive vice president of the Center for Climate and Energy Solutions, a nonpartisan climate-focused think tank, told Business Insider that he's not too worried about about other countries abandoning the agreement, and is confident that most will remain committed to climate action.

"I don't think they'd want to expose themselves to the sort of international condemnation the US is likely to face," said Diringer, who has attended nearly every United Nations climate conference since the first meeting was held in Kyoto two decades ago. "But I do worry that a US withdrawal will have a corrosive effect on global ambition, in the sense that countries will not be as zealous in meeting their targets, and put forward less ambitious targets when the next round is due in 2020."

The next time the United States wants the rest of the world to support one of its priorities, experts warned, other countries may not want to help.

US "credibility and leverage on other foreign policy issues would take a huge hit," said Mark Tercek, president and CEO of the Nature Conservancy.

"The nations of the world rightfully expect US policy to be foresighted and steadfast," he wrote in a blog post. "Trump has an important opportunity to show the world that the promises of the United States are durable, especially with respect to a universal threat as serious as climate change."

What happens next?

Beyond signing the overall agreement, each country also submitted a climate-action plan laying out how it would adopt clean energy and phase out fossil fuels. This allowed each nation to individualize and edit their commitments, adding flexibility to the Paris agreement so that it could bend without breaking.

The US's plan, which the Obama administration submitted in March 2015, set the goal of reducing greenhouse gas emissions by 26% to 28% by 2025. The baseline level this reduction is measured against is 2005, when the US emitted 6,132 million metric tons of carbon dioxide.

Because of the way the agreement was designed, it would take years for the US to fully exit the pact. The rules state that, if Trump simply cancels Obama's pact, the earliest the US can say it's leaving the accord is November 2019, and wouldn't officially exit until November 4, 2020 - the day after the next presidential election.

While Obama agreed to the Paris accord through executive action, the US Senate approved the original treaty that was the UN's basis of the overall Paris agreement back when George H.W. Bush was president in 1992.

Exiting the overall UN agreement would take a year, but would likely require Senate approval.

Obama also pledged the US would give $3 billion to help developing nations deal with the worst of climate change's effects, $1 billion of which the US has already sent to poorer nations. Trump can cancel that promise apart from the Paris deal.

An unstoppable market

Globally, renewables like wind, solar, and hydropwer only made up about 11% of the energy used in 2016.

Supporters of clean energy may see that as a depressing number, but companies see it as an untapped business opportunity. Investments in renewable energy surpassed those in fossil fuels in both 2015 and 2016, and analysts expect that trend to continue until the carbon-burning energies like gas, coal, and oil are eventually phased out.

Some of the largest American companies urged Trump not to exit the Paris deal, arguing that doing so would hurt their bottom line. Not only would leaving increase uncertainty and risk, the companies argue, but it could also make them less competitive worldwide.

Apple, Facebook, Google, Microsoft, Morgan Stanley, and Salesforce are just some of the major companies that asked Trump to keep the status quo in a letter that appeared as full-page ads in the New York Times and the Wall Street Journal.

"As businesses concerned with the well-being of our customers, our investors, our communities, and our suppliers, we are strengthening our climate resilience, and we are investing in innovative technologies that can help achieve a clean energy transition," the letter read. "For this transition to succeed, however, governments must lead as well."

Fossil fuel companies Exxon Mobil, Shell, PG&E, and ConocoPhillips even expressed their support for the deal, arguing that it allows the US to have a seat at the table for oil negotiations.

Tesla and SpaceX CEO Elon Musk threatened to leave Trump's advisory councils if he canceled the Paris agreement, saying if the president did so, he would have "no choice."