GENEVA (AP) — The three main greenhouse gases hit record high levels in the atmosphere last year, the U.N. weather agency said Wednesday, calling it an “ominous” sign. Earlier on Wednesday the U.N’s climate office said current pledges to cut greenhouse gas emissions put the planet on course to blow past the limit for global warming countries agreed to in the 2015 Paris climate accord. It said its latest estimate based on 193 national emissions targets would see temperatures rise to 2.5 degrees Celsius (4.5 Fahrenheit) above pre-industrial averages by the end of the century.