Current international scenarios for limiting global warming to less than 1.5°C by the end of the century rely on technologies that remove carbon dioxide (CO2) from the Earth’s atmosphere faster than humans release it.
The most aggressive emissions reduction projections from the UN Intergovernmental Panel on Climate Change (IPCC) will require the removal of between six and 10 billion tons of CO2 per year by 2050 to stick to the 1.5˚C warming pathway.
But the new findings suggest that existing CCS projections are unlikely to be feasible at the current rate of growth.
The study found that while it might be possible to store up to 16 gigatonnes of CO2 underground each year by 2050, reaching this target would require a huge increase in storage capacity and scaling over the coming decades, which is not plausible given the current pace of investment, development and deployment.
The team from ICL’s Department of Earth Science and Engineering created models showing how quickly carbon storage systems can be developed and deployed, accounting for the availability of suitable geology and technical and economic limitations to growth.
“There are many factors at play in these projections, including the speed at which reservoirs can be filled, as well as other geological, geographical, economic, technological and political issues,” said lead author of the study Yuting Zhang.
“However, our models will help us understand how uncertainty in storage capacity, variations in institutional capacity across regions and limitations to development might affect climate plans and targets set by policymakers.”
The analysis suggests that projections from IPCC reports for Asian countries including China, Indonesia and South Korea, where current development is low, assumed unrealistic rates of deployment – which means existing projections are unlikely and unreliable.
The team’s calculations suggest that a more realistic global benchmark is in the range of 5-6 gigatonnes of storage per year by 2050, which aligns with the speed at which similar technologies have been scaled up over time.
Co-author Dr Samuel Krevor said: “It’s important to keep in mind that five gigatonnes of carbon going into the ground is still a major contribution to climate change mitigation. Our models provide the tools to update current projections with realistic goals for how and where carbon storage should be developed in the next few decades.”
In 2022, the UK’s Climate Change Committee said that carbon offsets were being overused by firms to mask insufficient efforts being made toward eliminating their own emissions.
Source: E&T
