Carbon capture, ocean fertilisation and offsets trading (part 3)

I appear to have neglected this series of posts based on a Royal Society seminar I attended in London last month. Sorry about that, and also for the lack of detail in this third instalment, which focuses on a presentation given by Columbia University environmental engineer Klaus Lackner.

Lackner’s talk was primarily about managing carbon dioxide emissions from the burning of fossil fuels, but he began with a very large-scale systems analysis of worldwide energy use. We were subject to a blizzard of impressive-looking graphs, and a few of these threw up interesting facts. For example, in a plot of energy consumption versus GDP, Norway comes out above the US in terms of relative energy consumption.

We are not running out of fossil fuels, says Lackner, who spoke at length about remaining coal reserves, oil from tar sands, and other sources. But I’m not sure this squares with the facts. Or at least, huge uncertainties in accepted figures for remaining coal reserves could drive a coach and horses through Lackner’s and others’ arguments about fossil fuel resources.

In this week’s New Scientist magazine is a fascinating article by David Strahan, author of “The last oil shock: a survival guide to the imminent extinction of petroleum man”. Strahan explains how difficult it is to determine the extent of coal reserves (economically recoverable coal) and resources (total amount in the ground). He also notes that in recent years many countries have revised their official coal reserves downwards, in some cases massively.

Can we rely on the official figures, and rest assured that coal will be mined for a long time to come, or are we approaching the time of “peak coal”?

Basing his argument on the assumption that coal burning will continue for many years to come, Lackner talks of the need to totally eliminate carbon dioxide emissions associated with this form of electricity generation. Current emissions targets are, he believes, insufficient, and we need zero emissions to bring down carbon dioxide levels to the pre-industrial 280 parts per million level.

Lackner believes that it will be possible through carbon capture and storage (CCS) to achieve a net zero carbon economy. This could, he says, be brought about through a combination of mineral sequestration and totally-closed energy cycles using new fuel burning technologies. Deriving synthetic liquid hydrocarbons is also a possibility, and these are certainly preferable to hydrogen in terms of energy density.

How much will it cost to move to such a system? A lot, but Lackner says that the costs involved are less than variations in the price of oil over the past few years. Also on the subject of economics, Lackner speaks of the need to move from a system of carbon credits to one of “certificates of sequestration”.

There was more in Lackner’s presentation than I could digest in one go, and some of what I did follow has left me with niggling doubts. I have written elsewhere about clean-burn technologies, and am confident that they could work on an engineering level. But it’s a question of when, the costs involved, and the political will necessary to bring about such radical change.

I shall wind up this series of posts in a day or two with a brief comment on carbon offsets trading.

To be continued… (see part 1; part 2)