Greening a desert. Would this be worth a try?

[mistermack]

5 hours ago, TheVat said:

The GBR experiment is different in several ways from what we are discussing, so it does not address the issues I was talking about. 

Except that they are turning sea water into vapour by spraying. Despite the "enthalpy of vaporization" making the project impossible. But wait, maybe the heat energy in the air is doing exactly what I said. And you seem a bit confused about condensation nuclii. Without an abundance of them, the cooling vapour just forms bigger drops, rather than clouds of smaller drops which give a more reflective cloud. Bigger drops would be fine, if you are just aiming to make it rain. 

From the report I linked : 

"When you have very clean air, like we have coming in over the reef during summer, there's not very many of these cloud condensation nuclei."

This means clouds form with a small number of larger droplets, which are not good at reflecting light.

"So when you add extra sea salt crystals, you get the same cloud but it's now made up of many more smaller droplets and that reflects more light back into space," Dr Harrison said."

I don't have any updates on the experiment, but as they've been running it for three years, they obviously are not expending unimaginable terrabites of energy doing it. By now they would know for sure, if the energy consumption was horrendous, and would have closed it. 

After all, there is no prospective cash return on what they are doing, whereas if you successfully greened the climate in the right place, it could be worth billions. 

 

[StringJunky]

37 minutes ago, mistermack said:

Except that they are turning sea water into vapour by spraying. Despite the "enthalpy of vaporization" making the project impossible. But wait, maybe the heat energy in the air is doing exactly what I said. And you seem a bit confused about condensation nuclii. Without an abundance of them, the cooling vapour just forms bigger drops, rather than clouds of smaller drops which give a more reflective cloud. Bigger drops would be fine, if you are just aiming to make it rain. 

Condensation nuclei from seawater comes in the form of dimethyl sulphide, produced by phytoplankton. If we spray it in the air, I would have thought DMS would be liberated into the air at a higher rate?