Genetic Switch Lets Marine Diatoms Do Less Work at Higher CO2

Minutely small marine plants called diatoms mitigate climate change by consuming carbon dioxide and producing oxygen. But they may reject the rising levels of the greenhouse gas.

Diatoms – those tiny ocean-dwelling photosynthesisers that produce a fifth of the planet’s oxygen each year – may not gulp down more carbon dioxide more enthusiastically as greenhouse gas levels in the atmosphere continue to rise.

Instead, they may switch off and use the gas more efficiently.  If so, the consequences for the rest of the planet could be uncomfortable.

Climate scientists who try to model the machinery of the atmosphere have always banked on a “fertilization effect” from at least some of the extra CO2 pumped into the atmosphere by the human burning of fossil fuels and the clearance of the forests.  They may no longer be able to do so.

The discovery – reported in Nature Climate Change – is based on laboratory experiments with one single-celled phytoplankton species called Thalassiosira pseudonana and meticulous study of its genetic mechanisms.

Read more at Greenhouse Gas-Guzzlers Spurn Extra Carbon Dioxide