This is something I’ve always wondered. All our current climate problems are due to pollutants released into the air and the ocean by human activity. It seems that efforts to prevent global warming are concentrating on reducing future release of these toxins. Couldn’t we, instead, put some sort of filter in the air and in the oceans to absorb these toxins?
This must not be feasible because if it would work I’m sure someone would have proposed it by now. Why wouldn’t it work? Is the volume of air and water simply too great to do something like this? Are we unable to build things that would remove toxins from the environment?
You’re talking about Carbon sequestration, and, yes, it is a possible solution to global warming.
It’s not easy, though. There’s a lot of carbon, and it may take a lot of energy to capture it in a way that it won’t just break free again.
Many of the methods for carbon sequestration are biological, and, as such, are essentially just renewable energy sources. If you grow plants, they’ll pull CO2 out of the atmosphere, and then you can burn the plants for energy. Do that enough (and efficiently enough, and you can stop burning as much oil and coal. Grow more plants than you burn stuff, and the net result is to pull carbon out of the atmosphere.
Where would you put it all? Assuming you’re talking about CO[sub]2[/sub], manmade emissions are something like 25 billion tonnes per year. Even if you remove the oxygen from the carbon dioxide, that still leaves you with seven billion tonnes of solid carbon to deal with.
There are such schemes though, but it’s more efficient to filter it out from power station chimneys rather than trying to soak it up once it’s already in the wider atmosphere. Then it can be pumped underground, for instance.
Once you have the carbon dioxide scrubbed from, say, a coal station’s chimney stacks, what’s the most stable way to store the carbon. How could you store it so that it wouldn’t just suddenly degrade and release many tonnes at once into the atmosphere?
You could:
a) Store it underground in depleted natural gas formations.
b) Turn it into a solid, like Calcium Carbonate
c) Let the ocean absorb it (bad idea, due to increased acidity).
d) Dissociate it into Carbon and Oxygen (great, if it could be done efficiently).