The world is currently on track to fulfil scenarios on diverting atmospheric CO2 to underground reservoirs, according to a new study by Imperial.

The capture and storage of carbon dioxide (CO2) underground is one of the key components of the Intergovernmental Panel on Climate Change’s (IPCC) reports keeping global warming to less than 2°C above pre-industrial levels by 2100.

Carbon capture and storage (CCS) would be used alongside other interventions such as renewable energy, energy efficiency, and electrification of the transportation sector.

The IPCC used models to create around 1,200 technology scenarios whereby climate change targets are met using a mix of these interventions, most of which require the use of CCS.

Their reports are available here and here. 

Now a new analysis from Imperial College London suggests that just 2,700 Gigatonnes (Gt) of carbon dioxide (CO2) would be sufficient to meet the IPCC’s global warming targets. This is far less than leading estimates by academic and industry groups of what is available, which suggest there is more than 10,000 Gt of CO2 storage space globally.

It also found that that the current rate of growth in the installed capacity of CCS is on track to meet some of the targets identified in IPCC reports, and that research and commercial efforts should focus on maintaining this growth while identifying enough underground space to store this much CO2.

The findings are published in Energy & Environmental Science.

Capturing carbon
CCS involves trapping CO2 at its emission source, such as fossil-fuel power stations, and storing it underground to keep it from entering the atmosphere. Together with other climate change mitigation strategies, CCS could help the world reach the climate change mitigation goals set out by the IPCC.

The study has shown for the first time that the maximum storage space needed is only around 2,700 Gt, but that this amount will grow if CCS deployment is delayed. The researchers worked this out by combining data on the past 20 years of growth in CCS, information on historical rates of growth in energy infrastructure, and models commonly used to monitor the depletion of natural resources.

The researchers say that the rate at which CO2 is stored is important in its success in climate change mitigation. The faster CO2 is stored, the less total subsurface storage resource is needed to meet storage targets. This is because it becomes harder to find new reservoirs or make further use of existing reservoirs as they become full.

They found that storing faster and sooner than current deployment might be needed to help governments meet the most ambitious climate change mitigation scenarios identified by the IPCC.

The study also demonstrates how using growth models, a common tool in resource assessment, can help industry and governments to monitor short-term CCS deployment progress and long-term resource requirements.

However, the researchers point out that meeting CCS storage requirements will not be sufficient on its own to meet the IPCC climate change mitigation targets.

Dr Krevor said: “Our analysis shows good news for CCS if we keep up with this trajectory - but there are many other factors in mitigating climate change and its catastrophic effects, like using cleaner energy and transport as well as significantly increasing the efficiency of energy use.”

Funding for this work was provided by ACT ELEGANCY, DETEC (CH), BMWi (DE), RVO (NL), Gassnova (NO), BEIS (UK), Gassco, Equinor and Total, the European Commission under the Horizon 2020 programme, the UK CCS Research Centre and EPSRC.

“Global geologic carbon storage requirements of climate change mitigation scenarios” by Christopher Zahasky and Samuel Krevor, published 21 May 2020 in Energy & Environmental Science.

Source: Imperial College London

Author: Caroline Brogan

Date: 21 May 2020