Who's a sucker for carbon dioxide?
There are two things you can do with carbon dioxide emissions: 1) reduce them; or 2) capture them and store them somewhere. Currently, most public debate seems to revolve around reducing output, but some interesting advances have been made at the capture end of the spectrum that are worth keeping an eye on.
Around 50% of carbon emissions from human activity are already absorbed by natural 'carbon sinks', like forests, oceans and soil, but the rest can hang around for as long as a hundred years.
There are lots of ways of potentially 'sequestering' carbon from the atmosphere, including 'biological, chemical and physical processes', after which you have to find somewhere like an disused oil field, the ocean bed or a reservoir to store it in - a process known as carbon capture and storage, or CCS.
The technology is in its infancy and the prevailing mood is 'let's wait and see if this thing works'. This extends to the British government, which has just OK'd the building of a new generation of coal-fired power plants on the proviso that that they can make CCS happen.
Within the last 12 months, scientists at Columbia University have discovered that a rock called 'peridotite', the most common in the Earth's mantle, naturally converts CO2 into minerals like calcite. Not only that, but they believe they can 'supercharge' the process by a million times, potentially storing up to 2 billion tonnes of carbon dioxide a year. (What makes it expensive is that the mantle is the layer directly below the Earth's crust, but it does occur sporadically on the surface, and mainly in Oman.)
Columbia has also given us the physicist Dr Klaus Lackner, who is working on a 'synthetic tree' that absorbs carbon dioxide but unlike a real tree doesn't expel oxygen. 'It looks like a goal post with Venetian blinds,' says Dr Lackner, helpfully.
Meanwhile over at UCLA, Omar Yaghi and team have created a 'nanoscale crystal that traps roughly 80 times its volume of carbon dioxide'. This is particularly exciting because it only has eyes for CO2 and nothing else.
And representing Britain we have Novacem, whose scientists have discovered a low carbon cement that requires half the heating of the usual stuff and actually absorbs carbon dioxide as it hardens, making it ultimately carbon negative. This is potentially a massive dose of good news for the global cement industry, which presently generates up to 5% of human carbon emissions.
Early days, but probably fair to say you can't write off the tech fix just yet.