(A) Never
(B) ** The very first day he is in office
(C) At some point in his presidency
(D) If the conditions get too bad to live in
EXPLANATIONS BELOW
Concept note-1: -Following the 2020 presidential election, President-elect Joe Biden vowed to rejoin the Paris Agreement on his first day in office. Once inaugurated, Biden signed an executive order to rejoin the agreement on January 20, 2021. The country formally rejoined the Paris Agreement on February 19, 2021.
Concept note-2: -The United States has a number of tools already on the books, under laws already passed by Congress, to cut carbon pollution. The country formally joined the agreement in September 2016 after submitting its proposal for participation.
Concept note-3: -As of February 2023, 195 members of the United Nations Framework Convention on Climate Change (UNFCCC) are parties to the agreement. Of the four UNFCCC member states which have not ratified the agreement, the only major emitter is Iran. The United States withdrew from the agreement in 2020, but rejoined in 2021.
Concept note-4: -On January 20, on his first day in office, President Biden signed the instrument to bring the United States back into the Paris Agreement. Per the terms of the Agreement, the United States officially becomes a Party again today.
Concept note-5: -As of February 2023, 194 states and the EU, representing over 98% of global greenhouse gas emissions, have ratified or acceded to the Agreement, including China and the United States, the countries with the 1st and 2nd largest CO2 emissions among UNFCCC members.