FILE - Barges float in the Mississippi River as a portion of the riverbed is exposed, on Sept. 15, 2023, in St. Louis. The U.N. weather agency is reporting that 2023 was the driest year in more than three decades for the world's rivers, as the record-hot year underpinned a drying up of water flows and contributed to prolonged droughts in some places. (AP Photo/Jeff Roberson, File)GENEVA (AP) — The U.N. weather agency is reporting that 2023 was the driest year in more than three decades for the world’s rivers, as the record-hot year underpinned the drying up of water flows and contributed to prolonged droughts in many places. The World Meteorological Organization also says glaciers that feed rivers in many countries suffered the largest loss of mass in the last five decades. WMO warned that ice melt can threaten long-term water security for millions of people globally. Its secretary-general says water is the “canary in the coalmine” for climate change — a distress signal for a warming planet.