Ocean Acidification and Carbon Dioxide Capture and Storage

My current project is managing a cross-government team to make recommendations on the required legal and regulatory framework for carbon capture and storage. This is the idea that carbon dioxide (CO2) can be captured at fossil fuel power stations (either pre or post-combustion) and other industrial processes. The gas would then be stored indefinitely rather than being emitted to the atmosphere, where CO2 is the main greenhouse gas. Storage is in underground (usually sub-seabed) rock formations such as exhausted oil and gas wells and in saline aquifers. It is therefore very interesting that OSPAR, the inter-governmental agreement to protect the North-East Atlantic, has just released new reports on the rapid increase in ocean acidification from CO2 in the atmosphere, and on the technical aspects of capturing and storing carbon dioxide in geological structures under the seabed. Made available by the OSPAR Commission as a result of the work of its Offshore Industry and Biodiversity Committees, they are available on www.ospar.org under 'What's New?'. (The site uses frames extensively - see here for the English welcome page et ici for the French one.) The reports will be formally published later in 2006.

The first report 'Ocean Acidification' confirms that high levels of CO2 in the atmosphere are changing ocean carbon chemistry at least 100 times faster than at any time in the last 100 000 years. The pH of seawater (the measure of the balance of acidity and alkalinity) has dropped from 8.2 to 8.1 over the past 200 years. Models forecast that it will drop to 7.8 by 2100, and may drop as low as 7.5 if there is a business-as-usual scenario. This would be lower than anything experienced in the last 10 - 20 million years.

Marine species that rely upon building up calcium-based structures will be adversely affected. These include corals, crustaceans (e.g. lobsters, crabs) and molluscs (e.g. mussels, oysters). Higher levels of CO2 in seawater generally depress the physiological performance of sea creatures, so it cannot be ruled out that the changes will also impact on other marine species.

The second report, 'Placement of CO2 in Subsea Geological Structures' looks at the technical aspects of CO2 capture and storage (CCS) in geological structures under the seabed. It shows that CCS in sub-seabed geological structures is technically feasible, using existing tried and tested technology. The North-East Atlantic offers significant potential for CCS: it could take most of the European Union's CO2 emissions from major point sources for several centuries. With well selected, designed and managed sites, retention of CO2 for several thousand years (or even longer) could be achieved. Evaluation of any proposed sites needs to take account of the risks to the marine environment as well as the benefits in mitigating climate change and acidification of the oceans. Monitoring will be important and the report describes how seismic and gravimetric techniques can be used.

The report concludes that guidelines or a framework for risk management for the storage of CO2 are needed. OSPAR is putting work in hand to produce these. (Taken from the OSPAR press releases.)

Global warming risk 'much higher' than IPCC forecast

Global temperatures will rise more than previous studies have indicated, according to new research to be published in the journal Geophysical Research Letters by two teams from the US and Europe. They used historical records to calculate the likely amplification of warming as higher temperatures induce release of carbon dioxide (CO2) from ecosystems and both conclude that current estimates of warming are too low, by anything up to 75%.

To calculate this extra warming, both research groups have looked back into the Earth's history. Regularly, spells of relatively high temperatures have produced rises in atmospheric carbon dioxide concentrations, which have fallen again as colder conditions took over. The theory is that in warm spells, ecosystems such as soils, forests and oceans retain less carbon.

As the Earth's surface is now warming again, the process might be repeating, with higher temperatures again causing the biological world to release CO2 into the atmosphere, adding to emissions from homes, factories and vehicles.

The US study examined a period of about 400,000 years using data from the Vostok ice core of Antarctica and expressed its results as a climate sensitivity of between 1.6 and 6.0C. The European group looked back to the ‘Little Ice Age’, a period in the middle of the last millennium when the northern hemisphere experienced relatively low temperatures and calculated that temperature rises in the future have been underestimated by between 15% and 78%.

The results are similar and challenge the consensus view of the Intergovernmental Panel on Climate Change (IPCC) , the global body charged with collating and analysing climate science, which predicts that the global average temperature would rise by between 1.5C and 4.5C if human activities were to double the amount of CO2 in the atmosphere.

From a BBC report. See the full version here.

Biomass Energy in England

I must apologise for the general lack of posts during the last month. I have been contributing to the UK Government's response to the Report of Sir Ben Gill's Biomass Task Force. As we approached the launch date things got more and more intense as we finished the last few detailed and sent the document to various government ministers for approval (a task made more difficult by the Easter holiday). Finally we launched the response at the end of April and the response can be down-loaded here.

For more details see my Energy News blog.