Policy Brief: Climate-Altering Technologies and the Arctic - C2G

[Andrew Lockley]

https://www.c2g2.net/project/policy-brief-climate-altering-technologies-and-the-arctic/ 

[Stephen Salter]

Hi All

The Carnegie Council Policy Brief on the Arctic mentions stratospheric aerosol as a method to save the ice.  However they make no mention of marine cloud brightening which could do the same.

Below shows work by Stjern et al. at the Cicero laboratory in Norway.     It is the mean of nine climate models following an a 50% increase of cloud condensation nuclei in ocean regions with low cloud. It shows large cooling effect over the Arctic, up to 3 Kelvin, for quite a gentle spray even through treatment was at also low latitudes.  The treatment was steady during the year.  I hope that adjustments  relative to the phases of monsoons might give a further improvement.

The report also shows that are small but useful increases in precipitation in many drought stricken regions.  Most of the reductions in precipitation are over the sea and so less serious than ones on land. The full report can be downloaded from       

                https://doi.org/10.5194/acp-18-621-2018-supplement

Jon-Egil Kristjansson warned that both marine cloud brightening and stratospheric aerosol worked in the wrong direction in winter. This is because changes to cloud in are reflecting long wave radiation back down. This is shown in several climate models such as the one below.  Despite the distortion of the Mercator projection the 8 watt/m2 increase over the Arctic would not be welcome.

It is fortunate that the short lifetime of tropospheric aerosol, about half the mean time between rain or snow showers, allows spray operations to stop in the autumn.

I have some calculations of the number of spray vessels which would be needed to get the Stjern 50% increase in the concentration of condensation nuclei.  I can send them, and also calculations on the number of vessels to control sea level rise, to anyone who would like to check them.  Please send me your email addresses.

Stephen

Emeritus Professor of Engineering Design. School of Engineering, University of Edinburgh, Mayfield Road, Edinburgh EH9 3DW, Scotland S.Sa...@ed.ac.uk, Tel +44 (0)131 662 1180, WWW.homepages.ed.ac.uk/shs, YouTube Jamie Taylor Power for Change

On 16/01/2020 09:51, Andrew Lockley wrote:

https://www.c2g2.net/project/policy-brief-climate-altering-technologies-and-the-arctic/ 

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