Concept
Climate change has led to the United States warming by 2.6 °F (1.4 °C) since 1970. The climate of the United States is shifting in ways that are widespread and varied between regions. From 2010 to 2019, the United States experienced its hottest decade on record. Extreme weather events, invasive species, floods and droughts are increasing. Climate change's impacts on tropical cyclones and sea level rise also affects regions of the country. Cumulatively since 1850, the U.S. has emitted a larger share than any country of the greenhouse gases causing current climate change, with some 20% of the global total of carbon dioxide alone. Current US emissions per person are among the largest in the world. Various state and federal climate change policies have been introduced, and the US has ratified the Paris Agreement despite temporarily withdrawing. In 2021, the country set a target of halving its annual greenhouse gas emissions by 2030. Climate change is having considerable impacts on the environment and society of the United States. This includes implications for agriculture, the economy, human health and indigenous peoples, and it is seen as a national security threat. States that emit more carbon dioxide per person and introduce policies to oppose climate action are generally experiencing greater impacts. 2020 was a historic year for billion-dollar weather and climate disasters in U.S. Although historically a non-partisan issue, climate change has become controversial and politically divisive in the country in recent decades. Oil companies have known since the 1970s that burning oil and gas could cause global warming but nevertheless funded deniers for years. Despite the support of a clear scientific consensus, as of 2021 one third of Americans deny that human-caused climate change exists although the majority are concerned or alarmed about the issue. Tropical cyclones and climate change Human-induced climate change has the potential to alter the prevalence and severity of extreme weather events such as heat waves, cold waves, storms, floods and droughts.
