sticky CO2

Storing greenhouse gas underground is a bit like storing nuclear waste: to be effective as a mitigation strategy, it has to be kept there indefinitely. Whether it's for carbon dioxide or nuclear waste, there is no proven long-term storage mechanism, so it would seem that the logical approach is to avoid creating these byproducts in the first place.

But we are sitting with a carbon challenge that won't go away quickly. We've already got enough of the stuff floating around to keep the mother ship toasty, and the rate at which we produce more of it is going up, not down. Because of this, climate scientists say we are already committed to global warming well into the future, even if we start reducing carbon emissions now. So what to do?

Unless we mothball everything that uses fossil fuels, and drastically reduce livestock herds right now, we may need to take carbon out of the atmosphere to avoid global warming consequences. With the best will in the world, planting trees just won't cut it. It's unlikely that we could plant enough to make a difference (it's proving difficult just to stop the destruction of existing forests, so can we really reverse the trend?), and trees are only a temporary carbon storage medium anyway.

Researchers have come up with an alternative; a device that vacuums CO2 molecules from the air. The molecules stick to absorbent compounds in the device, and then can be stored. Thanks to global air circulation, the device doesn't need to be located near the emission source; it can go wherever the carbon is to be sequestered.