Study: ‘Human activity disrupts ocean CO2 absorption’

A team of researchers with the Belgian professor Sebastiaan van de Velde as the lead author, reported that certain commercial activities damage the sea floors and disrupt the ocean’s natural carbon capture capacity. They also emphasized the need better to assess this “hidden emission” of greenhouse gases.

The oceans play a crucial role in regulating the climate by absorbing large amounts of CO2. According to scientists’ estimations, around 30 percent of the carbon dioxide (CO2) released by humans is absorbed by the oceans, playing a crucial role in climate regulation and reducing the rate of global warming.

Natural phenomenon

For this reason, this natural phenomenon of carbon capture currently receives a lot of attention, and more and more “technologies aimed at stimulating the ocean to absorb more CO2” are being developed, explained Sebastiaan van de Velde, the lead author of the study published in the journal Science Advances, in an interview with AFP. 

“However, we’re not asking the question, ‘What are we doing already that’s maybe not helping or reducing the oceans’ capacity to absorb CO2?’” he continued. 

Simulations

To research this, his team created models to simulate the impacts of bottom trawling and dredging – two commercial activities that disrupt the sea floors – on the oceans’ CO2 absorption.

Their analyses found several ways in which these practices reduce the alkalinity of the water, limiting the amount of carbon dioxide that can be absorbed. The study estimated that such activities reduce the absorption of between two and eight million tons of CO2 annually.

‘Hidden emissions’

Though the amount of these “hidden emissions” is relatively small compared to the total CO2 absorbed by oceans, the study found that human activity contributes to reducing their “carbon sink” efficiency.

Van de Velde said the study also shows that by “managing our current economic activities a little bit better”, we could “make quite easy gains in terms of CO2 uptake.”

Who is Sebastiaan van de Velde?

Dr. Sebastiaan van de Velde is the head of the National Marine Carbonate Chemistry Facility of NIWA and a lecturer in Marine Chemistry at the University of Otago, New Zealand.

Focusing on the biogeochemical cycles of carbon, iron, and sulfur, he studies the past and present oceans using a research approach that combines fieldwork, laboratory incubations, and numerical modeling at the local, regional, and global scales.