Climate news: Bittersweet discovery as oceans absorbing much more CO2 than thought – ESA | Science | News

New research from the European Space Agency (ESA) has found the ocean is absorbing much more carbon dioxide (CO2) which was thought to be being ploughed straight into the atmosphere. The observations from the ESA state that more CO2 is being absorbed by the oceans as previous studies had only looked at the surface temperature of the seas. The cooler the ocean is, the more CO2 it absorbs.

Previous research had found that as much as half of the CO2 was being absorbed by the oceans as they only looked at the surface temperate of the ocean.

However, dropping just one metre beneath the surface leads to a drastic temperature drop, which previous studies had not taken into consideration.

The research from the ESA found as much as 10 percent more CO2 is being absorbed by the ocean.

The corrected figures show the amount of CO2 was underestimated by up to 0.9 Gigatonnes of carbon per year – “a significant amount that, at times, doubles uncorrected values”, according to the ESA.

Andrew Watson of the University of Exeter, UK, lead author of the new study, said: “Previous studies have ignored the small temperature differences between the surface of the ocean and the sampling depth, but we know that this has a significant impact on how carbon is held by the oceans in terms of salinity, solubility, stability, and so on.

“But satellites can measure the temperature more or less exactly at the ocean surface – and when we do this, we find it makes a big difference.”

Co-author Jamie Shutler, also of the University of Exeter, added: “These results are consistent with independent estimates of the size of the oceanic carbon sink – those based on global ocean surveys by research ships.

“Now that these two separate estimates of the size of the carbon dioxide ocean sink agree pretty well, we can view and use their results with greater confidence, and trust that they are most likely giving us an accurate picture of what is going on.”

While this is good news for the atmosphere, which heats up as it traps CO2, it is bad news for the oceans.

Increased CO2 leads to ocean acidification, which affects the PH balance of the sea water, which leads to an increase in acidity – something which can destroy entire ecosystems, as is evident of the bleaching of the coral reefs.

The ESA’s Craig Donlon said: “The importance of our oceans in both regulating climate and supporting biodiversity cannot be overstated.

“Across all of ESA’s Earth observation activities, our aim is to fully account for the role of our oceans in terms of the carbon cycle.

“This key result, together with others built on the dedication and excellent collaboration of the ESA OceanFlux team, gives us a solid basis for that, and will help us to more accurately characterise and better understand our planet’s changing climate.”

Source link

Leave a Reply

Your email address will not be published. Required fields are marked *