BERLIN (AP) — A panel of scientists convened by the United Nations has published a report on the impact of climate change on the planet, including on the natural world and human civilization. The report by the Intergovernmental Panel on Climate Change concludes that nearly half the world’s population already faces significant risk from global warming. Its findings have prompted a strong reaction from officials, scientists and climate activists. U.N. chief Antonio Guterres called it an “atlas of human suffering.” One of its authors said “difficult choices will have to be made.” And activists are renewing calls for rich countries to step up both their efforts to curb emissions and provide financial aid to the poor.