Last updated by The POOG on October 20, 2020.
Cloud cover is one of the major factors contributing to global temperature yet is poorly accounted for in most climate models.
Cloud Contribution to Global Temperature
As Kauppinen and Malmi (2018) note:
In this paper we derive a new formula for the global temperature change and major feedback portions in the climate response. In our earlier paper we calculated from the experimental values the sensitivity about 0.058 K/(W/m2). This means the negative feedback which reduced the sensitivity by factor 2.13. In this paper we explain and derive the major portions in the feedback coefficient using the observed energy budget at the top of the climate and on the surface of the earth. The results also support strongly our earlier results of the low climate sensitivity (?T2CO2?0.24?C). The major portions in the negative feedback coefficient in shortwave insolation are roughly clouds 63%, evaporation cooling 28%, and water vapour 9%. The new sensitivity is 0.0605 K/(W/m2) which is reduced by factor 2.00. The changes in cloud cover or in the relative humidity explain almost all the global temperature changes. The result is confirmed with experimental observations. On the other hand, the sun and the change in the vegetation are probably controlling most of the changes in cloudiness and humidity.Kauppinen and Malmi (2018)
- Kauppinen, J. and Malmi, P. (2018) Major feedback factors and effects of the cloud cover and the relative humidity on the climate. arXiv:1812.11547v1 [physics.ao-ph], PDF.
- Rosenfeld, D., Zhu, Y., Wan, M., et al. Aerosol-driven droplet concentrations dominate coverage and water of oceanic low-level clouds. Science, 08 Feb 2019: Vol. 363, Issue 6427, eaav0566, DOI: 10.1126/science.aav0566.