The Paris Agreement is an international treaty designed to limit global warming by reducing greenhouse gas emissions. The agreement was signed in 2015, but former US President Donald Trump withdrew the United States from the agreement in 2017. However, as of 2021, the US has officially rejoined the Paris Agreement under President Joe Biden.

The Paris Agreement stems from the United Nations Framework Convention on Climate Change (UNFCCC), a global effort to address the issue of climate change. The agreement was adopted by consensus by the 195 UN member countries in December 2015 and aims to limit global warming to well below 2 degrees Celsius (3.6 degrees Fahrenheit) above pre-industrial levels. Additionally, the agreement seeks to pursue efforts towards limiting the increase to 1.5 degrees Celsius.

The United States was one of the countries that played a significant role in the negotiation of the Paris Agreement, but former President Trump famously announced the country`s withdrawal from the agreement on June 1, 2017. The decision was met with international criticism, with many world leaders expressing their disappointment and concern over the move.

While the US was officially out of the agreement for four years, individual states and cities continued to work towards reducing their carbon footprint and upholding their commitment to the Paris Agreement`s goals. However, the absence of the US as a nation was a significant setback to the global effort to tackle climate change.

On his first day in office, President Biden signed an executive order to rejoin the Paris Agreement, following his campaign promise to prioritize climate change action. The President`s decision was met with widespread support from environmental groups and leaders across the world, who saw the move as a critical step towards combatting climate change.

In summary, the US officially rejoined the Paris Agreement on January 20, 2021, under President Joe Biden`s administration. The move marks a significant return to the global effort to tackle climate change and underscores the importance of international cooperation towards reducing greenhouse gas emissions. As the world continues to grapple with the impacts of climate change, the Paris Agreement remains a critical framework for collective action towards a sustainable future.