By JAMEY KEATEN
GENEVA (AP) — A U.N.-backed report says sites containing some of the world’s most treasured forests, including the Yosemite National Park in the U.S., have been emitting more heat-trapping carbon dioxide than they have absorbed in recent years. According to the report released Thursday, factors like logging, wildfires and clearance of land for agriculture are to blame. The excess carbon turns up from just 10 of 257 forests classified among UNESCO World Heritage sites. The study adds to growing signs that human activities and the fallout from climate change have transformed some natural carbon sinks that suck up CO2 from the air into net sources of it. Scientists say climate change has made weather extremes like drought and wildfires more likely.