Because of its high energy consumption, the US has long emitted more carbon dioxide than any other country. Because carbon dioxide remains in the atmosphere for about 120 years, it accumulates, becomes equally distributed around the world, and has global effects. Thus, while using large amounts of energy to achieve economic growth, the US and other wealthy nations have unintentionally burdened the rest of the world with a long-term problem. And many negative impacts of climate change are likely to be more severe for poorer countries that lack the resources to adapt.