Extreme weather & GHG concentrations

This press release says that IPCC will be discussing the impact of climate change on “extreme weather,” but that report will not come out until 2021 (!).┬áIn the meantime, here’s the relevant table from the last report (2013) [pdf]. Click to enlarge.

Notes: In reading through that summary, I noticed that they do mention “extra melting” from Greenland and Antarctica, but that estimates of warming are not agreed upon. It is due to this “lack of consensus” that the potential for 6-9m of sea level rise by 2100 (Hansen 2016) is not featured in the report (it estimates 0.2m at most).

The IPCC uses RCPs (Representative Concentration Pathways) of “radiative forcing in year 2100 relative to 1750” to run its models. The “best case” (RCP 2.6) implies a CO2equivalent atmospheric concentration of 475ppm (of which CO2 is 421ppm) by 2100. Those figures are now 489 and 405ppm, respectively. (Hint: that’s bad news for adequate, timely mitigation.)