The year 2021 is now expected to qualify among the hottest seven in history, all of them recorded since 2014, according to an early estimate by the United Nations World Meteorological Organization that was released Sunday. The widely anticipated annual estimate of the year’s temperature ranking and report on climate trends comes as diplomats converge on Glasgow, Scotland, for two weeks of UN talks. Countries will confer there on how to keep warming below 2°C (3.6° Fahrenheit) compared with preindustrial levels — and preferably 1.5°C . The world has warmed 1.1°C since industrialization in the 19th century. The atmospheric concentration of carbon dioxide, the biggest driver of this heating, has reached beyond 413 parts per million. That’s the highest in the modern record and also in the geologic evidence from the past 125,000 years . Methane and nitrous oxide, both more potent and less prevalent than CO₂, also reached […]