Land and Ocean Work Together to Control CO2

Land and ocean weathering are closely linked and together control how much carbon dioxide is stored or released into the atmosphere, a new study shows.

Weathering, the breakdown of rocks by water and chemical reactions, removes carbon dioxide and stores it as calcium carbonate in soils or the ocean.

The study, published in Nature Geoscience, finds that processes on the seafloor are connected to weathering on land and should be studied as a continuous system.

Carbon captured on land can be lost when sediments reach the ocean, researchers say. This has implications for enhanced weathering, a proposed method of removing CO2 by speeding up natural rock breakdown.

“If rock weathered on land eventually reaches the ocean, it could reverse weathering and cancel out the CO2 removal,” said Jeremy Rugenstein, a co-author and geosciences professor at Colorado State University.

He added, “We still know very little about these reverse processes, which makes their role in cancelling enhanced weathering a major open question.”