Carbon Capture Is Not a Climate Savior The promise of negative emissions is baked into most “net zero” pledges. But putting that into practice is easier said than done. Sarah Rice/Getty Images Algae at the wastewater biofuel system at the San Francisco Public Utilities Commission's Southeast Water Pollution Control Plant (shown here in 2012) capture carbon dioxide and produce biofuel. In December, the Vatican became one of the latest entities to unveil a plan to reach net-zero emissions by 2050, joining far less pious actors like BP, Shell, and President-elect Joe Biden. Net-zero plans have become all the rage as public concern about the climate crisis has grown. But approving coverage of these wide-ranging announcements rarely question what the “net” of net-zero actually means.