27 August 2009

UK Institution of Mechanical Engineers on Air Capture

The Times reports today:
Giant fly-swat shaped "synthetic trees" line the road into the office, where blooms of algae grow in tubes up the walls and the roof reflects heat back into the sky - all reducing the effects of global warming.

All this could be a familiar sight within the next two decades, under proposals devised by the Institution of Mechanical Engineers to alter the world's climate with new technology.

A day after John Prescott, the former Deputy Prime Minister and Environment Secretary, warned that negotiations for a global deal to cut carbon emissions were in danger of collapsing, the institution is recommending a series of technical fixes to "buy time" to avert dangerous levels of climate change.

It says that the most promising solution is offered by artificial trees, devices that collect CO2 through their "leaves" and convert it to a form that can easily be collected and stored.Tim Fox, head of environment and climate change at the institution, said that the devices were thousands of times more effective at removing carbon from the atmosphere than real trees.

In the first report on such geo-engineering by practising engineers, the institution calculates that 100,000 artificial trees - which could fit into 600ha (1,500 acres) - would be enough to capture all emissions from Britain's homes, transport and light industry. It says that five million would do the same for the whole world.
The IME report can be found here. Its recommendations are smart, and not just because they are consistent with my own related work, which you can see here:

Pielke, Jr., R.A., 2009. A Perspective Paper on Climate Engineering, Including an Analysis of Carbon Capture as a Response to Climate Change, Copenhagen Consensus Center.

Pielke, Jr., R. A., 2009. An Idealized Assessment of the Economics of Air Capture of Carbon Dioxide in Mitigation Policy, Environmental Science & Policy, Vol. 12, Issue 3, pp. 216-225. See FAQ Page on Air Capture.


  1. Reading the details of the document confirms my skeptical view that this is not smart.
    It says that on current technology the 'tree' captures 1 tonne per day, but it is 'conceivable' that it could be increased to 10, and the 100,000 trees figure is based on this. The cost of building the things is estimated at $2bn and then the cost of capturing the CO2 'could drop to as low as' $30/tonne, (much lower than the figure in Roger's paper) so could only cost $30M per day! The cost of storing the stuff underground is not even mentioned. And all this is based on the estimates of the proponents of these schemes.

  2. What I don't understand is why would you distribute carbon dioxide capture along motor ways. I'd prefer the site of real living trees growing the roads. If you want to capture carbon, why not an algae plant with a much more concentrated exhaust stream direct from a coal or gas fired power plant? The waste low grade heat from the plant would even keep the algae warm year round.

  3. I gotta tell ya, that cover art doesn't inspire confidence that the Institution of Mechanical Engineers has even the foggiest idea what they're talking about.

    Those "trees" and windmills are so close and so similarly oriented that they would experience serious negative interactions.

    I was a member of the American Society of Mechanical Engineers (ASME) for many years. If the ASME published a report with cover art that ridiculous, I'd hope some heads would roll.