Global emissions of carbon dioxide are continuing to rise despite years of policy efforts to control them. Humans have now done so much damage to the atmosphere that halting the burning of fossil fuels alone will not prevent a climate catastrophe. So, if cutting carbon emissions isn’t enough, can we tackle the problem at the other end – by sucking carbon dioxide out of the air?
Here are the key approaches to carbon capture that could help to save our planet:
Chemical capture
A UK company founded by a chemistry professor has secured £3.5 million in investment to develop a novel technology for capturing carbon emissions.
C-Capture, launched by the University of Leeds in 2009, raised the capital in an equity funding round led by BP, energy firm Drax and tech investor IP Group.
The cash injection will be used to develop the carbon capture technology, support larger pilot projects, and increase global marketing efforts.
Carbon capture and storage involves trapping emissions of carbon dioxide and disposing of them in permanent storage such as disused gas fields. High costs have previously limited its deployment, but C-Capture says it can make the process “significantly more economic” by using solvents first developed by its co-founder Chris Rayner.
Fossil fuel companies such as BP are particularly interested as carbon capture could legitimise the continued use of their products. C-Capture’s technology is already being used in a small-scale trial at Drax’s power plant in North Yorkshire.
C-Capture’s solvent is fitted into an emissions flue and reacts to absorb the carbon dioxide from the gas passing through it. The solvent can then be removed and heated up, releasing the carbon dioxide so it can be compressed for storage. The solvent can then be re-used. C-Capture says this is safer and less expensive than existing technologies, which use chemicals derived from ammonia.
C-Capture has received more than £2 million in UK government funding.
The ‘perfect plant’
Microbiologists are working on a ‘perfect plant’ that could hold enough Co2 in its roots to help curb climate change.
The Salk Institute for Biological Studies in the US is conducting trials as part of its Ideal Plant Initiative. The aim is to design a new generation of plants that, planted on a large scale, could suck enough carbon dioxide out of the atmosphere to help slow climate change.
Salk is talking to seed companies and preparing to do tests on major agricultural crops – including wheat, soybeans, corn and cotton – so that its Ideal Plant might one day be introduced on farms around the world.
Normally, plants return most of their carbon back to the atmosphere when they decompose, leaving only a tiny fraction behind in the ground.
This forms part of an annual carbon cycle, as plants take in carbon dioxide during spring growth, and release it back to the atmosphere when they decay in the autumn — a bit like the Earth breathing.
Professor Joseph Noel, a chemist working on the Ideal Plant project, had a eureka moment when he remembered the compost heap he had as a kid, recalling corks that didn’t decay.
Last autumn the team found a gene that could dramatically increase the content of a molecule called suberin – which is cork – in a plant’s roots.
Professor Noel said: “Now, not only can we select varieties of plants that bury carbon in the soil … it also allows the plant to survive with less water or with more water.”
Retain and replant trees
Simply preserving the trees we already have by halting practices such as large-scale land clearing and burning would be a major step in improving CO2 levels in the atmosphere. Stopping deforestation in Indonesia and Brazil alone could reduce emissions equivalent to those produced by every car and light truck on the road in the US.
Retaining trees does more than just pull carbon from the atmosphere. Because the Amazon produces its own moisture, tree loss can lead to drought and fire, which could quickly destabilise and flip the forest to another type of landscape – one that would release its stored carbon.
Replanting trees, on the other hand, could reduce atmospheric greenhouse gases. Simply restoring forests already chopped down in Brazil could draw about 1.5 billion metric tons of CO2 out of the air.
While each of these approaches offers some hope for tackling climate change, a growing number of climate advocates believe that a combination of nature and technological solutions is needed if we are to avoid disastrous consequences.
Even better, of course, is to switch to a fully renewable energy economy. To find out more about how you can invest in renewable energy, helping both the planet and your purse, see the Good With Money guide, “How to Invest in Renewable Energy“.
