climate-debate, to keep an eye on...

NASA: We Can’t Model Clouds, So Climate Model Projections Are 100x Less Accurate

by K. Richard, August 30, 2019 in ClimateChangeDispatch

NASA has conceded that climate models lack the precision required to make climate projections due to the inability to accurately model clouds.

Clouds have the capacity to dramatically influence climate changes in both radiative longwave (the “greenhouse effect”) and shortwave.

Cloud cover domination in longwave radiation

In the longwave, clouds thoroughly dwarf the CO2 climate influence. According to Wong and Minnett (2018):

  • The signal in incoming longwave is 200 W/m² for clouds over the course of hours. The signal amounts to 3.7 W/m² for doubled CO2 (560 ppm) after hundreds of years.

  • At the ocean surface, clouds generate a radiative signal 8 times greater than tripled CO2 (1120 ppm).

  • The absorbed surface radiation for clouds is ~9 W/m². It’s only 0.5 W/m² for tripled CO2 (1120 ppm).

  • CO2 can only have an effect on the first 0.01 mm of the ocean. Cloud longwave forcing penetrates 9 times deeper, about 0.09 mm.

…