Some good news for a change on climate change. Firstly, scientists in the US have discovered a cheap way of extracting carbon dioxide from power plant exhaust gases. Currently this requires expensive amine solutions or membrane filters, but apparently it can be done with cheap activated charcoal. The CO2 is then released by heating it, allowing it to be compressed and piped elsewhere for geological storage. The down side? What they want to use it for is pushing more oil out of the ground - something which will likely more than offset any savings made. Idiots.
Meanwhile, another group of scientists have invented a cheap(ish) atmospheric scrubber able to suck carbon dioxide from the air (yes, there's an obvious joke here about trees, but these are far more efficient). Their prototype, which they expect to have working within two years, will be the size of a shipping container, suck a ton of carbon dioxide a day, and cost around 100,000 pounds (giving a price of ~NZ$80/ton assuming a ten year lifespan). But it will get significantly cheaper with mass production, meaning that this could become quite cost effective if carbon prices rise (as they are expected to).
The downside with both technologies is that you need somewhere to put the CO2. While geological storage sounds very promising, and can clearly be Done Right, the big concern is that if left to the free market it will be done wrong. Why after all would a for-profit company spend money which could go to shareholders on properly ensuring the safety of their storage field, when they could simply take the money, then declare strategic bankruptcy and dump the problem in the public's lap, just as they do for every other environmental problem? So, while there's some interesting technological possibilities here, this is not something we can afford to let the market anywhere near without a tight regulatory framework to ensure they do it properly.