If electricity had a colour then today that would be black, and so would the water circulating in our heating (or cooling) pipework. Not as dark black as 40 years ago, but certainly not a pastel green. Somewhere well out of sight is a vast generating plant - which burns stuff, usually fossil coal and fossil gas. That isn't going to change any time soon - because we all want cheap electricity. Today, green electricity isn't cheap, and there is not enough available when needed.
That will change slowly. Our electricity now is less black because of switching from coal to gas; it will get a bit more so by replacing gas with nuclear, and by adding some wind and solar. But for the next 30-60 years we are committed to staying pretty dirty, because of the power plant equipment being built. The terrible problem is that fossil fuels are just so cheap, so available and so very convenient.
In the rational part of our collective head, we know that climate belts are moving pole-wards, the world is warming, weird weather happens more, sea-level is rising. Computer climate models show irretrievable breakdown of the world we know within our (grand) children's lifetimes. We understand that the upper ocean is becoming measurably more acidic. All that is plausibly linked to excess rates of carbon dioxide emission from those scarily convenient fossil fuels.
As a geologist, I can helpfully add that the rock record of 600 million years tells me that excess carbon dioxide has happened 5 times before - induced by volcanoes, or by continental configurations. Each time the results are strikingly similar - ocean death, extinction, and the top species vanish. That's us.
In the toolkit of remedies, we need something that's quick, will work with the equipment we have, and that can take the black out of convenient electricity. That something may well be a family of technologies going under the heading of carbon capture and storage (CCS).
With that set of technologies, you can burn fuel, catch the carbon, liquefy it and pipeline carbon dioxide deep into pores of salt-water sandstones and ex-oilfields. CCS can take out 95% of the carbon emissions at a power plant. Now add burning 10% of managed biomass at the powerplant, grown on displaced agricultural land - not competing with food or forest. That biomass grew using atmospheric carbon dioxide, and CCS systems can place that back underground.
Hey presto! The CCS package becomes a depletion pump, to stabilise the world atmosphere at less than crisis point.
The component pieces of technology for CCS exist today, though some are still 10 times too small. There is a challenge in putting the pieces together into a working power plant - and engineers are remarkably good at that. Capture is expensive right now, but the world has been here before with cleaning up power plant sulphur oxides, and then nitrogen oxides.
Each time it was an impossibly expensive imposition. But when cleanup became law, costs plummeted and it's now routine. Carbon oxides are the next frontier. As for storage, subsurface accumulations of carbon dioxide are well known. It's quite clear that nature has stored carbon dioxide, and it's clear what we need to imitate. Storage exists globally, in abundance. Enough for 100 years whilst we improve efficiency, build renewable energies, and invent a secure and sustainable nuclear power.
So why wait? The problem is money and political willpower. Although hundreds of green economy jobs are created in each CCS power plant, it's expensive - plus or minus a billion dollars per project.
But waiting brings us all closer to that sixth extinction. We're told we can't afford to build. But can we afford not to?
Professor Stuart Haszeldine will be joining four other brilliant technical innovators for Intelligence Squared's /www.intelligencesquared.com/events/energy-game-changers">Energy Game Changers at the Royal Institute of British Architects, London on 28 March in association with Shell and the International Herald Tribune as part of the 'Switched On' live events series.
Professor Stuart Haszeldine is the Scottish Power Professor of Carbon Capture and Storage at Edinburgh University.