Indeed, research shows that the cost of climate activity far outweighs the cost of reducing carbon pollution. A recent study suggests that if the United States does not meet its climate targets in Paris, it could cost the economy up to $6 trillion in the coming decades. A lack of compliance with the NPNs currently foreseen in the agreement could reduce global GDP by more than 25% by the end of the century. Meanwhile, another study estimates that achieving – or even exceeding – the Paris targets by investing in infrastructure in clean energy and energy efficiency could have great benefits globally – about $19 trillion. The NRDC is working to make the Global Climate Climate Action Summit a success by inspiring more ambitious commitments to the historic 2015 agreement and enhanced pollution reduction initiatives. The United States, the world`s second-largest emitter, is the only country to withdraw from the agreement, a move by President Donald J. Trump that came into effect in November 2020. Some other countries have not officially approved the agreement: Angola, Eritrea, Iran, Iraq, Libya, South Sudan, Turkey and Yemen. The authors of the agreement have set a withdrawal period that President Trump must follow – which prevents him from irreparably harming our climate. President Obama was able to formally enshrine the United States in the agreement through executive measures because he did not impose new legal obligations on the country. The United States already has a number of instruments on the books, under laws already passed by Congress to reduce carbon pollution. The country officially joined the agreement in September 2016, after submitting its request for participation.
The Paris Agreement was only able to enter into force after the formal accession of at least 55 nations representing at least 55% of global emissions. This happened on October 5, 2016 and the agreement came into force 30 days later, on November 4, 2016. Under the Paris Agreement, each country must define, plan and report regularly on its contribution to the fight against global warming.  There is no mechanism for a country to set an emission target for a specified date, but any target should go beyond the previous targets. The United States formally withdrew from the agreement the day after the 2020 presidential election, although President-elect Joe Biden said America would return to the agreement after his inauguration.  These rules of transparency and accountability are similar to those in other international agreements. Although the system does not include financial sanctions, the requirements are intended to easily monitor the progress of individual nations and promote a sense of overall group pressure, discouraging any towing of feet among countries that might consider it. The Paris Agreement (the Paris Agreement)  is an agreement within the framework of the United Nations Framework Convention on Climate Change (UNFCCC) that deals with the reduction, adaptation and financing of greenhouse gas emissions and was signed in 2016.