Seas capturing more carbon than expected European research says

IOM3 Content Cafe
22 Sep 2020

Our seas help to slow global warming by absorbing carbon from our atmosphere and new research uses data from ESA, NASA and NOAA satellites to show that far more carbon is absorbed by the oceans than previously thought.

There are ongoing efforts to collect and compile in situ measurements of the ocean sink in the form of the Surface Ocean CO₂ Atlas (SOCAT), which holds over 28 million international observations of our oceans and coastal seas from 1957.

Andrew Watson of the University of Exeter, UK, lead author of the new study published in Nature Communications, entitled Revised estimates of ocean-atmosphere CO2 flux are consistent with ocean carbon inventory, notes that previous studies ignored the small temperature differences between the surface of the ocean and the sampling depth. This is important because it has a significant impact on how carbon is held by the oceans in terms of salinity, solubility and stability. The satellite data takes the temperature at the ocean surface making a big difference.

Correcting this difference shows the net flux of carbon into the oceans is underestimated by up to 0.9 Gigatonnes of carbon per year, in some cases, double the uncorrected values. These new results are consistent with independent estimates of the size of the oceanic carbon sink based on global surveys by research ships.

The potential for slowing global warming further is welcomed but removing more carbon dioxide from the air, affects the oceans, making them more acidic, harming marine life.