Ende des Jahres hatte der Deutsche Wetterdienst bereits einen 2016er-Hitzerekord für hierzulande vermeldet, dasselbe gilt jetzt auch global: 2016 war das heißeste Jahr seit den Aufzeichnungen und erreicht mit fast 1,5°C schon jetzt die Grenze dessen, was im Paris Abkommen ausgehandelt wurde: Earth on the edge: Record breaking 2016 was close to 1.5°C warming. Well done, Menschheit.
C3S found that global temperatures in February 2016 already touched the 1.5°C limit, though under the influence of a strong El Niño, an intermittent event involving a period of warming. Global temperatures still remained well above average in the second half of 2016, associated partly with exceptionally low sea-ice cover in both the Arctic and Antarctic. […]
In addition to record temperatures, ECMWF’s Copernicus Services monitored other extremes occurring in 2016, including significant global wildfires and the growth of CO2 in the atmosphere. Destructive fires were observed around Fort McMurray, Canada in May and then extensive wildfires across Siberia, associated with the year’s high surface temperatures, during June and July.
For the first year CO2 levels did not return below 400 ppm as summer turned to autumn in the Northern Hemisphere. In previous years, take-up of CO2 by vegetation during the summer growing season has typically seen September mark the lowest point for CO2 levels.
In other GIFs: The unprecedented drop in global sea ice, in one terrifying gif.
— Kevin Pluck (@kevpluck) 5. Januar 2017
Systems with amplifying feedbacks tend to have tipping points beyond which change is irreversible. In the case of the great polar ice sheets that will drive catastrophic sea level rise and ultimately inundate every major coastal city, we appear to be dangerously close to such tipping points.
Alarmingly, what happens in the Arctic does not stay in the Arctic. The accelerated loss of Arctic sea ice drives more extreme weather in North America, while speeding up both Greenland ice sheet melt (which causes faster sea level rise) and the defrosting of carbon-rich permafrost (which releases CO2 and methane that each cause faster warming).