What Biden’s Emissions Goal Means to a Warming World

The U.S. is seeking to reduce the greenhouse gases it produces by at least half by 2030, as President Joe Biden carries out his decision to rejoin the Paris Agreement. America’s new commitment -- officially known as a nationally determined contribution, or NDC -- is much more ambitious than its initial one. It will need to be. Climate change hasn’t slowed enough since the landmark international pact was signed in 2015, and several other nations that have already increased their own objectives.

NDCs are the heart of the Paris Agreement among almost 200 countries to reduce the fossil fuel pollution that causes climate change. They’re voluntary targets that each nation sets for themselves, committing to cut greenhouse gas emissions by a specific amount. They vary from country to country and are generally based on multiple factors, including how much of those heat-trapping gases a country generates, what kind of changes people and businesses there are willing to make, and what it would take politically to make that happen.