Summary: For 27 years, the United Nations has held annual gatherings of world leaders to discuss how to combat climate change. Yet progress towards the goal of stopping global warming has been elusive, and this year's summit is happening against the backdrop of host country Egypt's record of human rights abuses. Sarah Kaplan, climate reporter for the Washington Post, joins Ali Rogin to discuss. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders
