The US' greenhouse gas emissions fell 10.3% in 2020, the largest drop in emissions in post-World War II era, due to COVID-19, the Rhodium Group reported. By comparison, the 2009 economic recession caused emissions to drop by 6.3%. Under the 2009 Copenhagen Accord, the US pledged that by 2020, it will have cut its emissions by 17% from 2005 levels.