In his second inauguration speech, U.S. President Donald Trump made a lengthy promise to reverse some of the climate-friendly energy policies adopted by the Biden administration. On his first day in office of his second term, he signed an executive order withdrawing the United States, the world's largest historical emitter of greenhouse gases, from the Paris Agreement for the second time in a decade. Established in 2015, the Paris Agreement seeks to limit global temperature rise and includes nearly every nation except Iran, Libya, and Yemen. The U.S. exit positions it among only four countries outside this vital accord, which aims to reduce greenhouse gas emissions globally.