Just hours after being inaugurated last Wednesday, President Joe Biden began his presidency by signing a series of Executive Orders, one of which re-entered the United States into the Paris Climate Agreement. Though the United States only formally exited the agreement last November, the country has been relatively absent as a key player in climate negotiations since Donald Trump took office in 2016. Biden’s move, viewed by many as the return of U.S. leadership in climate action, has been celebrated by many world leaders and climate campaigners (Reuters, New York Times).

Leaders in the European Union have been some of the quickest to express their praise. French President Emmanuel Macron was among the first to comment, tweeting out a warm welcome back to the agreement to the United States (U.S. News and World Report, Twitter [FR]). British Prime Minister Boris Johnson followed suit, hailing the announcement as “hugely positive news” (Los Angeles Times, Twitter). Johnson has further stated that he is hopeful that the United States will follow the actions of other major countries and commit to carbon neutrality by 2050 (Reuters).

Climate policy experts are hopeful that these exchanges, as well as Biden’s quick start on climate, signal substantive cooperative action to come (New York Times). In a recent memo, the European Union noted that carbon border policies, which place levies on the import of high pollution products, present a great opportunity for collaboration with the Biden Administration. President Biden had likewise identified instituting such policies in the United States as a goal during his election campaign. Implementation of these policies by both the European Union and the United States could exert great pressure on other countries, like China, to expedite their decarbonization efforts as well (Reuters).