O.K. what is your take on the albedo effects of the persistent cirrus, nuclei, etc.?
On a global scale? I have no idea. I could see a number of possible scenarios, but I do not know which of them, if any, reflect reality. The atmosphere is really rather poorly modeled because there are so many interactions on so many scales that could have an impact.
Anyone who tells you otherwise is either a fool or is trying to sell you something.
I have obviously read a lot of research and comments regarding this whole mess over the last several days and there seems to be a group of scientists making assumptions regarding albedo and contrail induced cirrus clouds . . . let me see if I can find you some sources . . .
Greenhouse gases and cirrus clouds regulate outgoing longwave radiation (OLR) and cirrus cloud coverage is predicted to be sensitive to the ice fall speed which depends on ice crystal size. The higher the cirrus, the greater their impact is on OLR. Thus by changing ice crystal size in the coldest cirrus, OLR and climate might be modified. Fortunately the coldest cirrus have the highest ice supersaturation due to the dominance of homogeneous freezing nucleation.
Seeding such cirrus with very efficient heterogeneous ice nuclei should produce larger ice crystals due to vapor competition effects, thus increasing OLR and surface cooling. Preliminary estimates of this global net cloud forcing are more negative than −2.8 W m−2 and could neutralize the radiative forcing due to a CO2 doubling (3.7 W m−2).
A potential delivery mechanism for the seeding material is already in place: the airline industry. Since seeding aerosol residence times in the troposphere are relatively short, the climate might return to its normal state within months after stopping the geoengineering experiment. The main known drawback to this approach is that it would not stop ocean acidification. It does not have many of the drawbacks that stratospheric injection of sulfur species has.
[link to iopscience.iop.org] /
There are a lot of assumptions made by a lot of people. And they are just that: assumptions.
