WASHINGTON (AP) — President Joe Biden will pledge to cut U.S. greenhouse gas emissions at least in half by 2030 as he convenes a virtual climate summit with 40 world leaders. That’s according to three people with knowledge of the plans who spoke on condition of anonymity because they were not authorized to discuss them. The 50% target would nearly double the nation’s previous commitment and help the Biden administration prod other countries for ambitious emissions cuts as well. The nonbinding but symbolically important pledge is a key element of the two-day summit, which begins Thursday as world leaders gather online to share strategies to combat climate change.