Greenhouse gas emissions halted new ice age, study finds

Global warming has likely halted the onset of a new ice age on Earth, according to a new study. Greenhouse gas emissions interrupted the natural accumulation of Arctic ice that began around 2,000 years ago. The research, led by geochemist Nicolas Young of Columbia University and published in Science, focused on the Barnes ice cap, a remnant of the Laurentide Ice Sheet. Using beryllium-10 and radiocarbon dating, scientists found the ice cap was expanding toward glaciation until the Industrial Revolution's emissions reversed the trend. The ice cap peaked around 1960, after which rising summer temperatures prevented its winter recovery. Scientists say these last remnants are now doomed to disappear, eliminating the natural mechanism for returning to an ice age period.