Meanwhile, 2016 is on track to become the year that the Earth’s carbon dioxide levels officially passed the symbolic 400 ppm mark for good, according to a report in The Guardian. Many scientists contend that the carbon dioxide levels should remain well below 400 ppm to avoid long-term disruptions to the Earth’s climate. Carbon dioxide levels are typically at their lowest in September because plants in the Northern Hemisphere absorb more CO2 throughout the summer. But levels have remained above 400 ppm. Shakun called it unrealistic and not matching historical time periods of similar carbon dioxide levels.

Source: National Post September 28, 2016 18:00 UTC