Possibly the most important word in the world right now
Slashdot. Ah, Slashdot! So much gets reported there, and so often is it mauled in the comment threads. Take this recent thread on the discovery of a way to increase the CO2 absorbent qualities of a particular plastic. I actually made this subject one of my projects at school, and have posted a tiny summary of our findings elsewhere on this site.
Slashdot's usual pundits reacted to this little news item with derision and bewilderment. However, if this simple plastic both absorbs and releases its CO2 rapidly, and if it can withstand more than a few hundred cycles of doing it before deteriorating, it could literally save the planet. There's really nothing else out there you could say the same about.
It's like this: if you chase the references at the bottom of my page on carbon air capture, you'll discover that no amount of emissions reductions nor geoengineering of global temperature will prevent climate disaster at this stage. Even if we stopped putting new carbon dioxide into the atmosphere overnight, what's already there will continue to acidify the oceans and alter the climate for centuries. We are already on an irreversible course to mass extinction.
...Unless it somehow became feasible to remove the CO2 that's already in the air. Some of the Slashdot commentators naively suggested planting trees, but that's not actually a viable solution (especially as we are cutting trees down far faster than we can reforest, and the climate will kill forests faster than we can replant them anyway). What's needed is an industrial-scale solution. People like David Keith and Klaus Lackner have experimentally proven that it can be done, and even Keith's system, which uses off-the-shelf chemicals and processes, is economically viable provided there's a high price on carbon. However, if the polyethylenimine results hold up, they'll represent an orders-of-magnitude reduction in the difficulty of capturing atmospheric carbon. This translates to commercial viability at a credible carbon price.
In other words, we don't have to either bury our heads in the sand or accept the inevitability of mass desertification, mass extinction, ocean anoxia and economic catastrophe. When combined with actual emissions reductions, carbon air capture technology has the potential of returning the atmosphere to pre-industrial levels of CO2 within our lifetimes. It is the only measure that can actually reverse climate change.
So remember the word polyethylenimine. This unassuming plastic might just save the world.