hydrogen

On the Science Show today they talked at length about some new developments in generating hydrogen cheaply for fuel in large algal ponds. Pretty amazing stuff. It turns out that the world's energy requirements can be met by a surprisingly small area of ponds.

While I'm delighted that people are working on alternatives to petroleum as fuel, I can't help but worry about large scale adoption of hydrogen. Hydrogen is the "H" in H₂O -- water. Hydrogen is also the only element that routinely achieves escape velocity, that is, it leaves our planet. Since its earliest days Earth has been losing hydrogen into space. This is not something that can be easily reversed... well, unless we go and collect more from some the other planets in the solar system -- not something we're likely to in the near future. We've shown many times that we are really sloppy about leakages and spills, but even if we were really careful such leaks are bound to happen, and if the world's economy changed over to hydrogen they would happen often. Dumping large amounts of hydrogen into the atmosphere would accelerate planetary loss. This, in time, would dry our planet because there would be less hydrogen available to make water. How long would it take to become a major problem? I don't know, but I'm pretty sure it would take much less time than you'd expect.

I'm surprised that nobody seems to have brought up that worry. It seems pretty obvious to me.