For the first time, the UN has declared that exceeding the Paris Agreement's 1.5C warming limit is "imminent and unavoidable ." "We are now saying this window has closed, but we can open it again by making the overshoot as brief as possible," UN Environment Program Executive Director Inger Andersen said on a call with reporters. "This is about how to find a way back as shortly and as quickly as possible with as limited an overshoot as possible." CNN reports: Past reports have examined the distance between countries' emissions reduction commitments and what it would take to limit global warming to 1.5 C above preindustrial levels. However, this year's report redefines the gap.…