The ocean's crucial carbon capture mechanism is slowing down
The Earth is actively fighting back against human-induced climate change. Some of the excess carbon dioxide we're pumping into the air is absorbed by "carbon sinks" like forests and oceans, which helps to slow down – but not stop – the greenhouse effect. Unfortunately, a new study has found that oceans are gradually becoming less effective carbon sinks, thanks to rising global temperatures.
Photosynthesizing organisms do most of the heavy lifting when it comes to bailing CO2 out of the air. Forests have stepped up their game in recent years, absorbing more greenhouse gases than usual and helping slow the rise of atmospheric CO2 levels. Meanwhile, plankton at the sea surface are gobbling up carbon in the water, and as they die, they drag it down to the depths of the ocean at a rate of about 6 billion tons a year.
But a study from MIT has found that warming of the waters is slowing down this natural sponging process. That's because photosynthesizing organisms flourish or flounder depending on the water temperatures – and so do respirers, creatures like bacteria and krill that absorb oxygen and release carbon dioxide. While photosynthesizers grow and die faster in colder waters, respirers are more active when it's warmer.
The delicate dance between these two competing yet symbiotic types of organism greatly affects how well the oceans perform as a carbon sink. The team developed a model to measure the "export efficiency" – the rate at which carbon is absorbed into the deep – at different temperatures, centered around the interplay between photosynthesizers and respirers.
"We had a simple way to describe how we think temperature influences export efficiency, based on this fundamental metabolic theory," says B.B. Cael, first author of the study. "Now, can we use that to see how export efficiency has changed over the time period where we have good temperature records? That's how we can estimate whether export efficiency is changing as a result of climate change."
To do so, the researchers gathered temperature data from three different sources, taken every month between 1982 and 2014 and reporting on locations all over the world. Then, they fed that information into their model to estimate the average export efficiency for the planet's oceans every month, and tracked how that changed over time.
Over those 33 years, water temperatures increased at the ocean surface, while the export efficiency decreased by between 1 and 2 percent. That might not sound like a whole lot, but it equates to an extra 100 million tons of plankton remaining near the surface every year.
"We figured the amount of carbon that is not sinking out as a result of global temperature change is similar to the total amount of carbon emissions that the United Kingdom pumps into the atmosphere each year," says Cael. "If carbon is just standing in the surface ocean, it's easier for it to end up back in the atmosphere."
The team says the model has the potential to be used to predict how effective the ocean will be as a carbon sink in the future, but it won't be as reliable thanks to uncertain temperature projections.
The study was published in the journal Limnology and Oceanography.
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If all the alarming news of the last 15 years had turned out to be true, we would all have been dead long ago.
The science has been done. And by those that know and have access to more first hand information than anyone that's going to post on the comments here. Including me. It's been done many times over by scientist all over the world. And all recognize and agree with the findings.
Again... We don't really need to be a scientist to see something is happening. That change in nature is coming about at a very fast rate.
You want to say humans had nothing to do with it? Fine. Personally, i think you'd have to be a complete moron not to recognize the human impact on the planet. Some impact so bad you'll die in a very short order if you go visit certain areas that have been so damaged by human interaction. Waters that'll kill you by the time you finish the drinking a glass of it, again due to human interaction.
Be that as it may. There is a major change coming. Be out an ice age or what ever. Current CO2 levels beyond anything seen before. Who caused it.. let's toss that out the window for a moment. The fact is, adding to it is a bad thing. As humans we add too much. To much of a lot of things. And that needs to change. The Earth is a container, a confined space. Just a bigger one than an aquarium. But the principal for curing problems or things that get out of balance the same. If levels are too high, you have to lower them. If too low, you raise them. Balance is fragile. The smaller the confined space, the more critical it becomes. The Earth is out of balance. It will try to correct balance on its own. The father it goes out of balance the harsher the corrective measures. When nature tried to correct balance.. all kinds of crazy shit happens. Things get wacky as it attempts to re-establish balance. That's all that science is really trying to warn everyone about. How many times have people shown the world that fracking caused their water to be able to be lit on fire coming out of the faucet? Certainly more than once. How many times did the gas companies deny fracking had anything to do with it? And spread a "fad" of propaganda of denial. "Oh the water was like that" "Oh it's safe to drink!" Etc etc. You can join in the the current fad of denial... But keep in mind. If you're posting a comment on this. You just may be still alive to eat those words when nature comes a calling to balance the books. And nature.. well she don't care who's at fault, nor about profit and loss statements. I hope I'm here for it when it comes. When the ocean flicks the switch so to speak. It should prove interesting to say the least. Cheers...
That's 17,000,000 fewer acres growing deciduous trees (just in one state)... a huge carbon sink that now grows corn and beans for about 3 months a year and is raw earth for 9. Funny that Paris didn't mention midwest US de-forestation.