Humans have lived in the area of Yosemite for more than 4,000 years.
VOA: special.2009.01.07
So if we want to talk about the volume of that, we just talk about the surface area, which is 4 pi r squared, and we multiply that by the thickness d r.
It is not surprising, then, that this hitherto unobserved demographic change coincides with the collapse of the Akkadian empire, which controlled the area until 4, 200 years ago.
In theory, a solar shade could provide any amount of cooling, but the researchers estimate that it would have to have an area of 4.1m square kilometres (half the size of Brazil) to offset half the warming expected over the next century, assuming no cuts in carbon-dioxide emissions occur.
