Better Not Count on Carbon Capture to Reverse Global Heating

Atmospheric carbon dioxide is the primary fossil fuel emissions component which is responsible for global heating and the climate crisis. Photo: Image by Malte Reimold from Pixabay

That conclusion, based on a just-released paper from researchers at British Columbia's Simon Fraser University, warns that calculations which assume a 1:1 balance between the two carbon impacts would likely be significantly off.

So even if the whole idea of carbon capture is even feasible, at least on the scale the world might need it to be to save us all, it appears the entire basis for those past calculations of what we need to build is wrong.

"Because of the complexity of the Earth's system, things are not as simple as "one ton of CO2 in, equals one ton of CO2 out," says Kirsten Zickfeld, a distinguished professor of climate science in SFU's Department of Geography, and lead author for the report.

According to Zickfeld, this "asymmetry" implies that a larger amount of CO2 removal is required to compensate for a given amount of CO2 emissions if the atmospheric CO2 concentration is to remain unchanged.

Researchers used a series of climate model simulations to test whether the change in climate resulting from CO2 emissions and removals is asymmetric. Their results showed that the rise in the atmospheric CO2 concentration following an emission is larger than the decline following a removal of the same magnitude.

Findings of the study infer that balancing a given amount of CO2 emissions with an equal amount of CO2 removals could lead to a different climate outcome than avoiding the CO2 emissions.

"Our study suggests that assuming exact balance between CO2 emissions and an equal amount of CO2 removals in a net-zero framework risks blowing climate targets," she says.

While Zickfeld says that balancing emissions with CO2 removals of the same magnitude could lead to different climate outcomes, further study is needed to learn more about the extent of this effect.

The paper, “Asymmetry in the climate-carbon cycle response to positive and negative CO2 emissions,” by Kirsten Zickfeld, et. al., was published in the 21 June 2021 issue of the journal Nature Climate Change.