UN chief Ban Ki-moon

UN chief warns of dire consequences if climate change commitments broken

Ban, who will step down as head of the U.N. after 10 years at the end of this month, described climate change as the single most pressing danger facing the world and called last year’s Paris agreement his “greatest achievement” in office. The agreement, which was reached in December 2015 in Paris, outlines an action plan to limit global warming to well below 2 degrees Celsius compared with pre-industrial times.