The Ocean Is Still Sucking Up Carbon—Maybe More Than We Think
Excerpt: Recent studies looking at carbon-sequestering microbes suggest we still have a lot to learn about the ocean’s biological carbon pump. The ocean plays a critical role in carbon sequestration. Phytoplankton, which live on the warm, light-filled surface, suck carbon dioxide out of the atmosphere for food. They also need nutrients such as phosphorus and nitrogen from colder, heavier, saltier water that upwells into warmer layers. When phytoplankton die, they sink, bringing some of the carbon and other nutrients they consumed with them back to the ocean depths. Key to this circular process, known as the ocean’s biological carbon pump, is the vertical mixing of the surface and deeper water layers, which occurs through such mechanisms as currents, winds, and tides. ...traditional scientific models have long predicted that as the planet warms, this process would be disrupted, phytoplankton would be unable to thrive, and the ocean would sequester less carbon. Now, two studies have shown the limits of such models. One found evidence that phytoplankton may become more efficient as the ocean warms. The other reported the discovery of a new, widely distributed ocean microbe species that also has the potential to sequester carbon.…