Capturing and storing just 2,700 Gigatonnes (Gt) of carbon dioxide underground would make it possible for the world to keep global warming below the critical threshold of two degrees Celsius over pre-industrial levels by 2100.
That is the finding of a new study conducted by scientists at the Imperial College in London and published in the latest edition of the journal Energy and Environmental Science.
The current rate of carbon capture and storage, known as CCS, is on track to meet the goal of the Intergovernmental Panel on Climate Change (IPCC) to hold the line to less than two degrees warming over pre-industrial levels by century’s end.
Previously, scientists had overestimated the amount of carbon storage needed to meet the above goal, citing the need to sequester 10,000 Gt of carbon dioxide to hold the line on global warming.
Carbon capture works by trapping carbon dioxide in the location where it is emitted and storing it underground where it cannot be released into the atmosphere.
In order to meet the goal of holding the line on global temperature increase to prevent catastrophic climate change, the current rate at which carbon dioxide is being stored must be upheld without delays, the study warns. Research to identify additional underground locations where carbon dioxide can be stored must actively continue.
According to Christopher Zahasky of Imperial’s Department of Earth Science and Engineering, now at the University of Wisconsin-Madison, the world’s capacity to store carbon dioxide underground has increased 8.6 percent over the last 20 years.
If carbon capture is conducted at this rate alongside other methods of emission reductions, such as increased use of renewable forms of energy, more energy efficiency, and powering public transportation electrically, the world could meet the crucial IPCC target, something many doubted as being attainable.
“Nearly all IPCC pathways to limit warming to two degrees Celsius require tens of gigatons of CO2 stored per year by mid-century. However, until now, we didn’t know if these targets were achievable given historic data, or how these targets related to subsurface storage space requirements,” Zahasky said.
“We found that 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 suggest is possible. Our study shows that if climate change targets are not met by 2100, it won’t be for a lack of carbon capture and storage space.”