Why US greenhouse gas emissions rose last year

More than 30 years after the last major update of the Clean Air Act, the U.S. Supreme Court has upended the ability of Congress to give the Environmental Protection Agency and other federal agencies broad scope to combat air pollution, including the emission of greenhouse gases. Meanwhile, further Biden administration efforts to limit emissions face opposition in the courts. 

What began as a theory in the 1890s — that industrial emissions of carbon dioxide could increase global temperatures — had progressed to a scientific fact a century later. Scientists across a range of disciplines are studying the impact of the still-growing concentration of carbon dioxide and other so-called “greenhouse gases” in the atmosphere as they call for industrial and governmental policies to slow, then halt, the warming of the planet.