Environment

Acidic oceans may release more nitrous oxide into the atmosphere

Acidic oceans may release more...
Researchers have found that ocean acidification increases the amount of nitrous oxide released into the atmosphere
Researchers have found that ocean acidification increases the amount of nitrous oxide released into the atmosphere
View 1 Image
Researchers have found that ocean acidification increases the amount of nitrous oxide released into the atmosphere
1/1
Researchers have found that ocean acidification increases the amount of nitrous oxide released into the atmosphere

Having more carbon dioxide in the atmosphere isn’t just changing the surface climate – it’s making the oceans more acidic. Now, scientists have uncovered an unfortunate feedback loop that could make things worse. According to a new study, ocean acidification seems to increase the amount of nitrous oxide (N2O), a potent greenhouse gas, that’s released into the air.

Ocean acidification is already a major concern as a side effect of, and contributing factor to, climate change. More carbon dioxide in the air means the oceans absorb more of it too, which makes the waters more acidic. That in turn changes the climate of marine ecosystems, bleaching coral reefs, disrupting the natural food chain, messing up the survival instincts of fish, and even dissolving the seafloor.

And now a new effect has been uncovered by researchers at EPFL, Tokyo Institute of Technology and the Japan Agency for Marine-Earth Science and Technology (JAMSTEC). According to the team, more acidic waters release more nitrous oxide into the atmosphere. And once it’s up there, its greenhouse gas effect is almost 300 times more damaging than CO2, as it depletes the ozone layer.

The team started by collecting water samples from five different sites off the coast of Japan between 2013 and 2016. To test how much nitrous oxide was produced at different acidity levels, the team then lowered the pH levels of the samples, making them more acidic. This triggers a process whereby microbes in the water begin converting ammonium into nitrate, creating N2O as a by-product.

The team found that for one particular part of the Pacific Ocean – the subarctic areas near Japan’s northern island of Hokkaido – the more acidic water is significantly increasing the amount of nitrous oxide produced.

Interestingly, in their samples the team recorded that the actual conversion rate of ammonium to nitrate decreased, but somehow the amount of N2O produced went up. The team isn’t exactly sure what caused that, but it could be that pH changes are impacting other biochemical mechanisms in unexpected ways.

The new study backs up previous research that found that the conversion rate of ammonium to nitrate was dropping. The difference here is that the earlier work concluded that this meant that N2O levels would also drop – unfortunately the new study found just the opposite.

“Our study provides additional proof that rising CO2 emissions are disrupting natural biogeochemical cycles, which are highly sensitive to changes in the environment,” says Florian Breider, lead author of the study. “Our study shows that under the right conditions, one greenhouse gas can increase the production of another, more damaging one. So it’s essential that we keep conducting research in this area.”

The team acknowledges that for now, the conclusions are only really valid for that one part of the ocean that they tested. Further work will need to be done to determine if the phenomenon also applies to other regions.

The research was published in the journal Nature Climate Change.

Source: EPFL

5 comments
Nobody
One study says N2O should drop and another says it rises? Certainly not enough evidence to jump to any conclusions but still they use it to prop up the global warming theory. There was another recent story about 11,000 scientists declaring a climate emergency but quickly withdrawing the list of names. One story said that 600 names were checked before the list was withdrawn and only two could claim any scientific background and most were political activists who signed on to the story. So can you believe them? Not too hard to figure it out if it involves crushing taxes, increased government control and wealth redistribution. If someone comes out with a plan to rebuild our rail system and upgrade our power grid, then I must trust their motives. Just outlawing the use of bunker fuel in transport ships would do more than cutting air travel. When politicians pander rather than proposing any reasonable solutions they should be voted out. Right now we are watching the legalization of stoned voters. Global warming is the least of our problems.
Catweazle
According to Henry's Law, if the surface of the oceans is warming they will outgas CO2, not absorb it. In any case, the diurnal change in oceanic pH is well in excess to the alarmist claims of the climate catastrophists.
Robert in Vancouver
Schools and media have been repeating phony stories about global warming/climate change to the point it's a religious belief now. Nobody is allowed to question anything about climate change studies or you get labeled as an evil person, or worse. I remember very well in the 70's there were activists predicting global cooling because of CO2, and they had lots of "scientists" backing them up. That didn't go anywhere because there wasn't any internet and Al Gore didn't make a movie about it.
Tony Morris
@Nobody. One study took what seemed like a logical step and the later study proved categorically that acidification (in the sampled region) increases N20 release. The earlier study allows you to cast doubt on the later result which doesn't suit your agenda - that don't impress me much. @Catweazle. So you have highlighted an attenuation factor. CO2 release from the ocean doesn't occur until the ocean has warmed - ie the problem has already occurred. @ Robert IV. Schools teach the science. Deniers preach the religion. "Global Cooling" theory didn't get anywhere because it was BS - simple.
Nobody
Tony, I don't have an agenda but it is obvious who does when all their solutions are crushing taxes, socialism and government control. When I got my chemistry and physics degrees, a lot more proof was needed to determine if something was just a hypothesis, a theory or a law. Today our children are being taught that politically correct science is indeed fact, which it IS NOT. I do not deny that global warming is happening and has been for over 10,000 years. I do deny that it is the emergency that the politicians claim it to be and I do believe that the vast majority of their solutions are only intended to transfer wealth and power to control the world population. Your naivety doesn't impress me much either. Corrupt politicians, naive voters, and paid "me too" scientists are a far bigger problem than global warming.