A new study has questioned the efficacy of carbon capture technologies in reducing carbon dioxide (CO2) levels in the atmosphere, making them an ineffective weapon in the fight against climate change.

The research by Mark Z. Jacobson, a professor of civil and environmental engineering at Stanford University, reveals that carbon capture only reduces a small fraction of carbon emissions, contradicting the popular assumption that carbon capture actually reduces substantial amounts of carbon in the atmosphere. In fact, carbon capture technologies can cause more harm than good by increasing air pollution, says the study published in Energy and Environmental Science.

According to Jacobson, even if the equipment can ensure a 100 percent carbon capture, it is still worse – from a social cost perspective – than replacing a coal or gas plant with a wind farm. This is because carbon capture has a capture equipment cost while wind replacing fossil fuels doesn’t have a capture equipment cost and also reduces air pollution.

Analysing data from a coal electric power plant with carbon capture and a plant that removes carbon from the air directly, Jacobson found that the carbon capture equipment in both instances ran on power that came from natural gas. He then calculated the net CO2 reduction and total cost of the carbon capture process in each case, factoring in all the emissions associated with these plants. In both cases, the equipment captured about 10-11 percent of emissions they produced, against common estimates that say carbon capture can remediate 85-90 percent of carbon emissions.

Jacobson also calculated the social cost of carbon capture, taking into consideration factors such as air pollution, potential health problems, economic costs and overall contributions to climate change. Surprisingly, the cost was similar to or higher than operating a fossil fuel plant without carbon capture and higher than not capturing carbon from the air. He concluded that it was always better to use renewable electricity instead of coal or natural gas electricity or do nothing from a social cost perspective.

Jacobson goes on to say that solutions such as reforestation and eliminating sources of emissions and pollution would be smarter than relying on carbon capture technologies even if they ran on renewables. These solutions include reducing biomass burning, as well as halogen, nitrous oxide and methane emissions. However, the current reliance on carbon capture is diverting resources away from real solutions, delaying action on climate change.