The world is on track to capture and store enough carbon dioxide (CO2) to meet some of the targets set by climate experts on reducing the harmful effects of global warming, scientists have said.
New analysis from Imperial College London suggests that 2,700 Gigatonnes (Gt) of CO2 storage space would be sufficient to achieve the goals put forward by the Intergovernmental Panel on Climate Change (IPCC) – a UN body of scientists and economists which assesses the impacts and future risks of climate change along with options for response and mitigation.
According to the researchers, this is far less than the estimates by industry experts of what is available, which suggest there is “more than 10,000 Gt of CO2 storage space globally”.
However, they point out that meeting carbon capture and storage (CCS) requirements will not be sufficient on its own to achieve the climate targets and need to be combined with other interventions such as using cleaner energy and transport as well as increasing the efficiency of energy use.
CCS is a process which involves trapping waste CO2 from emission sources such as factories and power plants, and storing it underground to stop the greenhouse gas from entering the atmosphere.
It is one of the key measures recommended by the IPCC on keeping global warming below 2C, along with other interventions such as renewable energy and energy efficiency.
The researchers combined data on the past 20 years of growth in CCS, and found there has been an 8.6% increase in CCS capacity worldwide over the last two decades, which, they say, is on track to meet some of the targets identified in the IPCC reports.
Study leader Dr Christopher Zahasky, who is now an assistant professor at the University of Wisconsin-Madison but conducted the work at Imperial, said: “Nearly all IPCC pathways to limit warming to 2C 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.
“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.”
Commenting on the research, Grant Allen, a professor of atmospheric physics at the University of Manchester, who was not involved in the study, said that the promise of CCS as a “silver bullet” for offsetting emissions should be considered with caution.
He added: “As the study concludes, the growth of CCS installed capacity needs to accelerate before it can meaningfully offset emissions, and there is much more work to do to identify suitable storage locations.”
He said that the potential of CCS should not be seen as a reason not to cut carbon emissions now as there is no guarantee of its success.
Prof Allen added: “We need to accelerate both actions – carbon capture and emissions reduction.”