Bottom Trawling Could Be Producing More Carbon Dioxide Than Flying

It seems that there is almost no part of the planet where human activities are not playing a role in weakening the climate. Surprisingly, stratospheric fossil fuels by aircraft trolled on the ocean floor could be a bigger cause. However, a solution exists and it can bring many related benefits. Benthic trolling is the process of pulling the net so deeply behind a boat scraped to the bottom of the sea. The exercise has drawn a lot of criticism for the devastating effects it has had on marine ecosystems – but there another problem that has rarely noticed.

The ocean floor is the largest carbon dip in the world, trapping living things and releasing some carbon, locking them away from the ocean / atmosphere for thousands or millions of years. Finding ways to accelerate the precipitation of organic matter in ocean beds has become a big idea to deal with global warming. However, it only works if it lasts there.

A paper from Nature noted that if human activity churned ocean sediments, it would not have happened. 

In fact, Dr. Enrique Sala of the National Geographic Society and 25 co-authors calculate the amount of carbon they released when the nets crossed the ocean bed. Combining satellite data on the annual trawling and calculation of carbon, the paper estimates that 1.47 gigatonnes of carbon dioxide would fall to 0.58 guitars per year if all areas were fresh, if all areas frequently trolled. 

By comparison, the total contribution of all flights in a lockdown year is about one GT, although the controls widen the effects. Although excited sediment carbon does not reach the atmosphere directly, its presence in water reduces the ability to draw CO2 from the ocean’s atmosphere. Depending on how well it mixes with the surface of the deep water – an ongoing question – trawling below can be a big climate killer.

As deadly as this news is, Sala is just as overwhelmed. Certain areas of the ocean are much more sensitive than others are and have many environmental benefits, including greenhouse emissions if they protected. Sala said in a statement, “Global ocean life is declining due to overfishing, habitat destruction and climate change. Yet only 7% of the ocean protected in some way, “he said.

“In this study, we have led a new way to identify areas that – if protected – reduce carbon emissions as well as protect food production and marine life.” Demands to increase food production from fishing bans are counter-intuitive, but protected areas have shown to increase fish populations in the surrounding area, often increasing overall yields. If the paper were correct, 30 per cent protection of the sea – including protection of trawling on the bottom – would outweigh the financial and environmental rewards. Unfortunately, this will not happen immediately, so governments should be willing to invest in the future.

For those interested in doing so, Sala and co-authors have offered multiple maps that show which fields will bring the most benefits based on different criteria. “There is no best solution to save marine life and take advantage of these other benefits,” said Juan Mayorga, co-author of emLab. However, some areas prioritize any action. China’s seas identified as the largest lifters so far, emitting more than twice as much carbon as the mix of the next nine countries. However, much larger than Denmark population, unusually favor of a nation that prides itself on achieving climate-success.