Oops
"Considering that a grain of sugar is about .5 mm in size, you would have around 15 million grains of sugar in a cube of sugar. So, a million tons of atmosphere in comparison to entire atmosphere is about same ratio that about 200 grains of sugar is to a 10' cube room- or about the same small pinch of dirt on the floor. "
Sorry, it would around 27,000 grains instead of 15,000,000, so it would be less than 1/2 a grain