If you somehow collected all the water on planet Earth, you’d get a sphere with a radius of around 700 kilometers. Compare that sphere with the rest of the planet, and it doesn’t seem that big; have a look at Fig. 1. Of course, if you were on the Titanic on that infamous night in April 1912, this comparison would not have been much consolation. But it does give an idea of how big our “small” planet is, or rather how much sheer material makes up our planet.
It is interesting to see how that ball of water compares with a sphere that represents the Earth’s atmosphere. Lucky for me, there is a graphic for that too (Fig. 2).
In Fig. 2, the atmosphere sphere is the one on the right. It is bigger, which when you think about it is not surprising. The atmosphere is many kilometers thick all around the earth, while the deepest ocean trench is eleven or twelve km, but only in a relatively tiny area.
Now, what would be really interesting is to superimpose a sphere onto both graphics, which represents the amount of carbon dioxide that mankind has put into the atmosphere since, say, the First Industrial Revolution. Obviously the CO2 sphere would be much smaller than either air or water. But would it be noticeable as a graphic scaled to air and water?
So far today (2040 on Tuesday, May 15, 2012), Ontario fossil-fired power plants have made the CO2 sphere 33,057 tons bigger. It’s been a below-average day, generation-wise, in Ontario, where electricity comes with carbon emissions that are unusually low for an advanced industrial jurisdiction.
I shudder to think of the CO2 that, say, Germany has dumped into the air today. Though it is trumpeted to the heavens because of a few wind turbines and solar panels, half of Germany’s power comes from coal. A recent Reuters report said that Germany plans to add 46 new fossil-fired generators to its system, to cover the nuclear generators that are being phased out. Nuclear emits zero carbon; the most efficient of Germany’s 46 new fossil plants will emit half a kilogram for every kilowatt-hour it generates.
And let’s not forget where most of that carbon dioxide will end up. As I pointed out in “Oceans of Acid,” it will end up in the world’s oceans, represented by that relatively small sphere in the top graphic. Put CO2 into water, and the water turns acidic.
I’d like to know just how accurate that figure is; is it just taken from mean ocean/lake depths or allows for abysses and deep trenches and massive oceanic sinkholes and undersea calderas? (sp). Match that figure with Europa estimates!
Good questions James. The credit for the graphic goes to a guy from Woods Hole and another guy from the U.S. Geological Survey. I’d guess they did take fresh water lakes into account as well as the volume of water in ocean trenches etc.
Is Europa bigger than Rhea? I’ll have to crack my old astronomy textbooks!
Maybe those textbooks aren’t all that old, but still, you will probably get better information by cracking http://saturn.jpl.nasa.gov/index.cfm and a similar site for Jupiter that I don’t have the URL for right now.
We have nuclear-powered probes examining the outer planets, and yet somehow it’s not the future. Well, there were supposed to be people on board.