The Dry Earth: Reversed Terraforming
After terraforming Mars quite a few times, I’ve now done the reverse thing: martifying our own planet. What would Earth look like without a drop of water? When all lakes, seas and oceans suddenly disappeared? Our world would become a Pale Yellow Marble, a kind of cross-over between the Moon and Mars.
Exactly how much water is there on Earth? According to recent estimates, we’re talking about 1400 million cubic kilometers. That is a cube with sides of about 1,100 kilometers. The vast majority of that amount, 97 percent, is salt water. The other three percent consists of fresh water, water ice and water vapor.
A hydrogen molecule will occasionally escape the atmosphere, but that doesn’t seem to be happening on a large scale. Although that moisture loss will probably increase if global warming continues. But even then, these are small amounts. No, this warming is alarming enough, but in the short term it mainly means that we have to deal with more instead of less water.
On the other hand: sometimes planets lose a lot of water in the course of their existence. Mars, for example, once had a complete ocean in the northern hemisphere and there is nothing left of it. Why and how all that water disappeared is still a mystery. It is very speculative to assume that a somewhat clumsy technological civilization has had something to do with it, but it cannot be ruled out completely.
Let’s just say it’s a fun thought experiment, this Dry Earth. Or perhaps a nice setting for a 120-episode Netflix series about the last survivors who fight each other for life and death. And at least a nice print to put on the wall, to look at and think from time to time: it’s so good that we have water.