Citing concerns for US economic competitiveness and sovereignty, President Donald Trump held a Rose Garden ceremony yesterday to announce that he is withdrawing the US from the Paris climate agreement. The US will remain part of the United Nations Framework Convention on Climate Change and follow the agreement's procedures for leaving the accord, a process that will take until 2020. Moreover, the president stated he is open to renegotiating the deal or reaching a new climate change accord that is "on terms fair terms to the U.S." Nonetheless, the president's decision could have significant diplomatic and political repercussions and there is no clear global appetite to renegotiate the agreement.

In his speech, the president returned to many of the themes of his campaign to justify leaving the agreement. For instance, he argued that it imposed "unrealistic" greenhouse gas (GHG) reduction targets on the US while not requiring China and India to reduce their own emissions "for years to come." The president further contended that the agreement would result in significant economic costs to the American economy, citing consulting studies. Moreover, the president said that the agreement would keep the US from developing coal and other energy resources. In addition, the president argued that his decision was a reassertion of US sovereignty and will help to avoid potential litigation as the administration moves to roll back Obama-era climate change policies. EPA Administrator Scott Pruitt reportedly emphasized this last point to the president as the agency works to reverse the Clean Power Plan.

The process for withdrawing from the Paris agreement takes years and whether the US ultimately leaves the accord may be decided by the 2020 presidential election. The White House indicated that it will withdraw from the agreement pursuant to Article 28, which allows any Party to notice its withdrawal three years from the date on which the agreement entered into force. A party's withdrawal is not official then until one year later. Thus, since the agreement did not enter into force until November 4, 2016, the earliest the US could officially leave the accord would be November 4, 2020, providing the Trump administration with some time to renegotiate it. The slow withdrawal process also likely ensures that the agreement will be a campaign issue in the next Presidential election.

The landmark agreement commits all signatories, including developing countries, to put forth their best efforts to reduce GHG emissions and limit global temperature rises to 2 degrees Celsius, but contains no specific enforcement mechanisms. Rather the agreement is written to support a process of transparent reporting of these domestic efforts with a view to public pressure encouraging compliance.

The Obama administration had submitted an Intended Nationally Determined Contribution (INDC), which committed the US to reduce GHG emissions by 26 to 28 percent below 2005 levels by 2025. During President Trump's speech, he made it clear that the US would not implement the INDC. He also stated that he was ceasing US payments into the Green Climate Fund. (As part of the Paris agreement, developed countries committed to providing $100 billion in public and private financing to aid developing countries in addressing climate change opportunities and risks, including through support of the Green Climate Fund.)

The President's decision comes despite 2016 being the warmest year since records began in the 19th century and a 2014 finding by international climate change scientists that there is a 95 percent probability that man-made GHG emissions induced most of the temperature warming in the past century. The president's decision also comes amidst a significant expansion in renewable energy deployment over the past 10 years, with wind power accounting for over a third of the new utility-scale electricity generated since 2007, according to the US Energy Information Administration.

Notably, some influential Republican members of Congress, as well as US oil and gas interests, had urged that the president stay in the agreement. For example, in a letter to the President's special assistant for international energy and the environment, Exxon Mobil suggested that the US’s continued participation in the accord should be predicated on the international community providing concessions to the US and the fossil fuel industry, particularly with respect to carbon capture and storage. And Representative Kevin Cramer (R-ND) in a recent letter to President Trump argued that the US should remain part of the agreement if the international community provides financial support for technologies, such as carbon capture, utilization and storage, that can reduce fossil fuel’s emissions profile. Numerous Fortune 500 companies voiced public support for the US staying in the Paris agreement.

Some US states have already signaled that they are going to redouble their efforts to reduce GHG emissions in light of the President's announcement. The governors of California, New York and Washington announced they are forming the US Climate Alliance to coordinate the actions of states, cities and businesses to reduce GHG emissions. In addition, California Governor Jerry Brown (D) announced that his state will work with China on climate change notwithstanding US withdrawal from the Paris agreement. From Wall Street to Seattle, major US companies, such as Goldman Sachs, Johnson & Johnson, NIKE, Starbucks and Walmart, have pledged to source 100 percent of their electricity from renewable energy. So in the short term at least, state and corporate actions, combined with market forces favoring natural gas over coal, may keep the US on its current trajectory of reduced GHG emissions. The longer-term implications for US GHG emissions, however, remain unclear.