I was recently discussing the water crisis in Cape Town with my colleagues, and how they are currently heavily restricted in the amount of water they can use per day for fear that the entire city will run dry very soon. We often hear about how certain cities and countries are the driest they have ever been, and how this will only get worse as climate change progresses.
The thing is, I remember the water cycle from primary school. If certain parts of the world get drier, it means that other parts of the world get wetter. The planet as a whole cannot lose water. So, if it doesn’t rain anymore in South Africa, or California, it means that in other parts of the world it is going to start raining far more than usual.
The problem isn’t that the planet “runs out” of water, the problem is getting the water to the appropriate places. Given the way that the Earth is made, alot of that excess water is probably getting dumped into the oceans.
So, how to we transport that water to the places that need it most?
I proposed some kind of barge that could collect rainwater in the ocean and ferry it back to land. My colleague instead proposed a proper desalination method which is run on renewable energy, which can reextract water from the ocean.
I started poking about online and would you know, that second proposal actually exists, and they have been around for quite some time.