Tackling climate change means drastically reducing the world’s emissions. To do so we not only have to change our economy and society but also consider the use of carbon mitigation technology, specifically what’s known as carbon capture and storage (CCS).
CCS essentially means trapping carbon dioxide (CO2) at its emission source, such as a coal plant, and then storing it underground to keep it from entering the atmosphere. It’s an expensive process and there’s more than one way to do it.
The Intergovernmental Panel of Climate Change (IPCC), which groups the world’s leading climate experts, has included CCS on its checklist to keep global warming to less than 2ºC, as included in the Paris Agreement.
Almost four times less carbon has to be captured than previously thought in order to meet climate targets
A new study by Imperial College London said that no more than 2,700 gigatons (Gt) of CO2 would have to be captured to meet the most aggressive climate targets. This is much less than the previous estimates by academics and industry groups, which have suggested the need to capture more than 10,000 Gt of CO2.
The study also argued that the current rate of growth in the installed capacity of CCS is on track to meet climate targets. But research and commercial efforts should focus on maintaining this growth while identifying enough underground space to store this much CO2.
Until now, the amount of storage needed hadn’t been specifically quantified. To do so, the team combined 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.
There has been an 8.6% growth in the CCS capacity over the past 20 years, according to the study led by Dr. Christopher Zahasky. This means that the world is now on a trajectory to meet many climate change mitigation scenarios that include CCS as part of the mix.
"Even the most ambitious scenarios are unlikely to need more than 2,700 Gt of CO2 storage resource globally, much less than the 10,000 Gt of storage resource that leading reports suggested. If climate change targets are not met by 2100, it won't be for a lack of carbon capture and storage space,” Zahasky said in a statement.
The researchers said that the rate at which CO2 is stored is important in its success in reducing greenhouse gas emissions. The faster CO2 is stored, the less total subsurface storage resource is needed. This is because it becomes harder to find new reservoirs or make further use of existing reservoirs as they become full.
That’s why the researchers argued in the study that storing faster and sooner than current deployment might be needed to help governments meet the most ambitious climate change mitigation scenarios.
“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,” said co-author Samuel Krevor.
The study was published in the journal Energy & Environmental Science.