Where does Geo-Engineering fit in? September 14, 2009
Posted by CamdenKiwi in : Environment,renewable energy , trackbackHow’s this for a Dr Who plot? Temperature and sea levels rising, the oceans dying as they turn into an planet-wide acid bath, the last few humans huddle together in the far North plotting an heroic, last-ditch attempt to save the Earth by pumping sulphate aerosols into the atmosphere to recreate the cooling effect of Mt Pinatubo, or setting vast mirrors in space to reflect the sunlight away.
Perhaps more realistic are some of the technologies outlined in the Institute of Mechanical engineers report ‘Geo-Engineering – Giving us time to act?’. This report discusses three technologies which are, more or less, possible now.
- Artificial trees are machines which remove CO2 from the air, similar to the carbon capture devices advocated for power stations. These can be placed anywhere, perhaps beside a motorway, or in the middle of the North Sea, where the carbon captured could be stored in depleted oil wells.
- Growing algae on the sides of buildings would sequester carbon, with the resulting green goop used as biofuel, which could be burnt to biochar and later buried or stored underground, as well as insulating the building and reducing heating costs. Although its hard to imagine these photobioreactors really operating on a global scale, it could allow buildings become net carbon absorbers.
- Finally, the idea of increasing the albedo of buildings to reflect more sunlight back into space is an idea which has been around ever since the first villager in a hot country somewhere figured out limewash and painted her house with it. If applied to our modern sprawling cities, using uptodate highly reflective coverings, it would at least have a local effect.
From a Green perspective, should we just reject these technologies out of hand, or should we consider them as part of a balanced climate change strategy, along with power down emission reductions?
If, over the last 10-20 years that climate change has been seen as a major issue, carbon levels had at least started to come down, I’d say ignore all this. It’s an oil industry conspiracy to keep on with business as usual. But the truth is that the Green movement, party and campaigning organisations alike has been spectacularly ineffective at making any dent on global emissions. In the UK, we’ve reduced ours slightly since Kyoto in 1990, first by putting everyone onto gas heating and more recently by outsourcing our emissions to China. Even with all that, last year we managed a whopping 1.7% reduction.
We need ways of not just reducing emissions but of rolling back the damage already done. We desperately need time to adjust to a low-carbon world. These technologies could give us time, and a way of cleaning up.
The difficulty for any Green is that they could give us more than that. If (and its a big if) they fulfill their promise, then our high-consumption, growth obsessed world could continue a while longer, at least until the next resource blockage is reached.
A Green approach then has to consider a number of factors:
- Will the technologies work? Research spent on something that doesn’t is research not spent elsewhere.
- Will they have undesirable side effects, both environmental and economic?
- Are they sustainable?
- Is there an ethical concern?
The technologies which simply reduce warming (eg all the albedo increasing ideas) a symptomatic fix that does not get at root causes, and do not address the other effects of increased greenhouse gases. In particular, they do not address the problem of ocean acidification. Space mirrors and the like should be avoided, at least until its clear there is no alternative.
However Greens should support the idea of making buildings more reflective to reduce emissions by reducing the need for aircon, and perhaps to reduce local increases in temperature (urban heat island effect). This isn’t likely to have much effect on a global scale (see table 1 in Lenton and Vaughan (2009) ).
The idea of algae-based biophotoreactors should be seriously considered too. Most Green objections to biofuels have to do with the displacement of food crops, particularly in the developing world, and with unknown consequences of biochar. Algae, grown in tubes on the sides of buildings, or perhaps along roadsides or even in highly saline areas, don’t raise this objection. Unknown consequences should be researched, not abandoned in fear.
Because the artificial trees are an air capture and storage technology, and cost the same to capture carbon no matter how that carbon was originally emitted, they will effectively put an upper limit on amount paid for any emission reduction strategy. At the moment, they’re expensive, but it will come down and then noone will want to invest in renewables, changing transport patterns or anything else. If it works, all the other problems associated with fossil fuel dependency – peak oil, dependence on problematic suppliers, use of all those lovely molecules just to burn them – won’t go away.
Greens may therefore be reluctant to consider them, but if they actually work, they will give us time we desperately need. They’re worth a funding bet right now, and perhaps the chance of slowly coming off fossil fuels..
Geo-engineering contains some frightening possibilities, but, as the Royal Society said in their report on the state of the technology last week, we’re as much in danger of prematurely dismissing useful techniques as we are of promoting dangerous proposals.
When our grandchildren ask us why we didn’t just stop burning the oil, I don’t want to have tell them that not only did we see it coming and do very little, we abandoned the search for ways to clean up after ourselves.
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