Projects

Projects: Projects for Investigator

Addressing climate change by developing our understanding of the potential and limitations of a range of mitigation strategies is of unquestionable societal importance and urgency. Carbon Capture and Storage is one such strategy that is attracting significant international effort and the aim of this proposal is to greatly improve the understanding of the scale of impact a leakage from CCS systems might inflict on the ecosystem.

Hence our principle objective is to deliver information in a form that is directly applicable and usable by relevant policy, planning and public interest bodies that facilitates a knowledge based assessment of potential CCS impacts. In this respect specifically we will deliver:

1. Understanding that will underpin a formal ecological risk assessment of CCS.
2. A best practices guide to minimising ecological impacts from CCS.
3. Predictive models that are applicable to a comprehensive range of leak and impact scenarios.
4. Guidelines for the detection and monitoring of leaks, both acute and chronic.
5. Informative media summarising the projects findings for a range of stakeholders.

In order to achieve this we will work closely with stakeholders including CO₂ producers, policy makers, management organisations and environmental guardians to ensure that the project outputs are optimal and transferable.

However an understanding of impacts currently remains a very complex scientific problem, involving many branches of science, as we have to understand the interaction of CO₂ with geological, chemical and biological systems as well as the physics of CO₂ transfer and dispersion. Accordingly we have three over-arching scientific objectives:

• to quantify the transfer and transformations of CO₂ from the storage reservoir to the sea floor ecosystem, and ultimately into the atmosphere;
• to evaluate the biogeochemical and ecological impacts in the shallow sediment and the water column and
• establish techniques for the detection and monitoring of leaks by examining the spatial and temporal biological, chemical and physical signatures that may result.

Our research programme with be fully integrated with other CCS research (both past, ongoing and proposed) to maximize the value for money and the scientific return for the NERC investment.

In order to deliver our aims we have a number of specific objectives which are described as follows; each is the subject of a dedicated work package or the knowledge exchange program:

1. Engage with stakeholders to optimise the research and subsequent knowledge transfer, and produce a set of tools, reports and guides that directly transfer our scientificadvances to end users.
2. Determine the magnitude, fluid pathway, rate, spatial distribution and probability of potential CO₂ leakage from the storage reservoir to the marine ecosystem in stereotypical North Sea geological and environmental settings.
3. Develop and integrate existing physical, biogeochemical, and ecological models of the shallow sediments and water column to ultimately create a capability to predict the fate and impact of a wide range of leakage scenarios.
4. Define and quantify the processes that determine the fate of CO₂ released in terms of its biogeochemical transformations and potential to mobilise other chemical species within the overlying sediments and water column.
5. Determine the impact of CO₂ leakage on benthic ecosystems and their function.
6. Evaluate the techniques and protocols for monitoring leakage (including physical, chemical and biological indicators in both sediments and water column), and establish their sensitivity.
7. Develop a prototype predictive capacity for a wide range of leak scenarios, a risk assessment plan and a mitigation strategy relating to CCS leakage.

Climate change caused by increasing emissions of CO₂, principally the burning of fossil fuels for power generation, is one of the most pressing concerns for society. Currently around 90% of the UK's energy needs are met by fossil fuels which will probably continue to be the predominant source of energy for decades to come. Developing our understanding of the pros and cons of a range of strategies designed to reduce CO₂ emissions is vital. Of the available strategies such as wind, wave and solar renewables and Carbon Capture and Storage (CCS) none are without potential problems or limitations. The concept of CCS simply put is to capture CO₂ during the process of power generation and to store it permanently in deep geological structures beneath the land or sea surface. If CCS is successful, existing fossil fuel reserves could be used whilst new forms of power generation with low CO₂ emissions are developed. A few projects have been successfully demonstrating either capture or storage on limited scales, so it is established that the technical challenges are surmountable. Research is also demonstrating that the geological structures are in general robust for long term storage (for example oil deposits remain in place within geological strata). However geological structures are complex and natural sub surface gas deposits are known to outgas at the surface. Consequently it would be irresponsible to develop full scale CCS programmes without an understanding of the likelihood of leakage and the severity of impacts which might occur. The aim of this proposal is to greatly improve the understanding of the scale of impact a leakage from CCS systems might inflict on the ecosystem and to enable a comprehensive risk assessment of CCS.

The main location of stored CO₂ in the UK will be in geo-formations under the North Sea and our research concentrates on impacts to the marine environment, although our work will also be relevant to all geological formations. Research to date has shown that hypothetical large leaks would significantly alter sediment and water chemistry and consequently some marine creatures would be vulnerable. What is not yet understood is how resilient species are, and how big an impact would stem from a given leak. Our project will investigate for the first time the response of a real marine community (both within and above the sediments)to a small scale tightly controlled artificial leak. We will look at chemical and biological effects and importantly investigate the recovery time needed. We will be able to relate the footprint of the impact to the known input rate of CO₂. The results will allow us to develop and test models of flow and impact that can be applied to other scenarios and we will assess a number of monitoring methods. The project will also investigate the nature of flow through geological formations to give us an understanding of the spreadof a rising CO₂ plume should it breach the reservoir. The work proposed here would amount to a significant advance in the understanding and scientific tools necessary to form CCS risk assessments and quantitative knowledge of the ecological impacts of leaks. We will develop model tools that can predict the transfer, fate and impact of leaks from reservoir to ecosystem, which may be applied when specific CCS operations are planned. An important product of our work will be a recommendation of the best monitoring strategy to ensure the early detection of leaks. We will work alongside interested parties from industry, government and public to ensure that the information we produce is accessible and effective.