Method for Global Cooling

Do you really want cooling? Ever stop to think when we burn more fossil fuel? Summer or winter?

No need to do all this as there is no global warming despite the rise of greenhouse gases.

This is an interesting proposition, to coat areas of land with "artificial"
long lasting "snow" or other highly reflective and permanent item. I wouldn't
coat ANY areas of vegetation. But the real solution would be to coat every house
with asphault shingles with a reflective surface. Just think of the immediate, and
effective consequences of lowering the energy consumption and reflecting heat away
from millions of homes, especially around the deserty sunbelts.

You are considering spraying a reflective crystal substance over land regions to increase the reflectivity of the planet...
1. Cost. In order to make a dent in global warming you would need to coat literally billions of square miles.
2. 2/3 of the planet surface is water, which you cannot coat with anything.
3. 1/10th of the planet surface is white ice, which won't help.
4. RAIN will wash away your coating for every surface that is not desert.
5. Most desert land is already reflective.