Long-term control of climate change by carbon sequestration would require any leakages of carbon dioxide to be smaller than 1% per thousand years, concludes a study online this week in Nature Geoscience. If not, the leaked carbon dioxide would have to be re-stored continuously to maintain conditions close to a low-emissions scenario.
Gary Shaffer used an Earth system model to project climate-change impacts over the next 100,000 years. He compared five scenarios of carbon sequestration ― one for deep-ocean and four for geological storage ― with two extreme projections for climate change without sequestration: one with high emissions and one with low.
The author found that scenarios where leakage exceeds 1% per thousand years result in a large, delayed warming in the atmosphere as well as oxygen depletion, acidification and elevated carbon dioxide concentrations in the ocean.