Study Compares Climate and Health Benefits of Renewables vs. Direct Air Capture Investments Through 2050

A new study published in the science journal Communications Sustainability determined that money spent deploying wind or solar power delivers more combined climate and public health benefits than the same amount invested in direct air capture (DAC) technologies, even under extremely optimistic assumptions. S. grid regions from 2020 through 2050.

The study tested a DAC scenario based on current commercial performance, where 5,500 kilowatt-hours of energy is required to capture one American tonne of CO2 at a cost of $1,000 (around €851). It also examined an ambitious progress scenario in which DAC's energy use falls by more than two-thirds and its cost by half, to 1,500 kWh and $500 (€425) per tonne.

Under both the current commercial performance and ambitious progress scenarios, renewables delivered more climate and health benefits per dollar nationally.

Under today’s commercial performance, grid-connected DAC produced more greenhouse gases and air pollution damage through 2050 than it offset. Scientists further modeled a breakthrough scenario at 800 kWh and $100 (€85) per tonne, at the extreme low end of published projections. In this case, solar and wind continued to beat DAC across large portions of the country.

Dr. Jonathan J. The study authors noted that the analysis is not an argument against DAC technologies, which may still help decrease legacy atmospheric CO2 once ongoing emissions are largely abated.

Dr. Euronews reported that DAC technologies use chemical reactions to pull carbon dioxide out of the air. DAC processes draw ambient air into the system, where CO2 is isolated and separated through either a chemical or physical process.

Captured CO2 leaves the DAC system in its purest form, where it can be locked out of the atmosphere or reused. Captured CO2 can be injected deep underground for sequestration in certain geologic formations, according to the World Resources Institute. It can also be used in products, though the amount of carbon dioxide stored and how long it stays there varies.

Materials like concrete can sequester CO2 for centuries, the institute stated. 5 to 2°C limit. The study states that emission reductions need to be prioritised.

It further notes that if the global emission budget is exceeded initially and removals are applied afterward, a decline in the temperature cannot be guaranteed.