The ability of the oceans to absorb carbon dioxide is in danger

For the past century, humans have burned large amounts of fossil fuels and adding carbon dioxide added to the atmosphere. THE oceans they did a great job of absorbing some of that gas, reducing the temperature rise that occurs. However, scientists have now discovered that in the future this ability may decrease, leading to a process of heating even more severe.

These results come from a study carried out by a team of specialists belonging to the University of Texas in Austin, USA, where they analyzed a climate simulation configured for the worst-case emissions scenario and found that the oceans’ ability to absorb carbon dioxide (CO2) would peak in 2100, becoming half as effective at absorbing greenhouse gases by 2300.

The document was published in the specialized journal Geophysical Research Letters. As he warns, the decrease occurs due to the appearance of a surface layer of low alkalinity water that hinders the ability of the oceans to absorb CO2 since alkalinity is a chemical property that affects the amount that can be dissolved in seawater.

Although the emissions scenario used in the study is unlikely due to global efforts to limit emissions, greenhouse gas emissions greenhouse effect “The results reveal a previously unknown tipping point that, if triggered, would trigger a major drag on global warming,” the authors noted.

Megumi Chikamoto, who led the research as a researcher at the University of Texas Institute of Geophysics, said: “We need to think about these worst-case scenarios to understand how our CO2 emissions might affect the oceans beyond. of this century, but the next and also in the following one”.

Today, the oceans absorb about a third of human-generated CO2 emissions. Previous climate simulations had shown that their work decreased over time, but none had considered alkalinity as a possible explanation. To reach their conclusion, the researchers recalculated parts of a 450-year simulation until they found alkalinity as the main cause of the slowdown.

According to the results, the effect begins with a extreme climate change, which increases precipitation and slows ocean currents. This leaves the surface of the oceans covered with a warm layer of fresh water that does not mix easily with the colder, more alkaline waters below. As this surface layer becomes more saturated with CO2, its alkalinity decreases and with it its ability to absorb CO2.

The end result is a surface layer that acts as a barrier to CO2 absorption. This means less greenhouse gases go into the ocean and more are left in the atmosphere. This, in turn, results in faster heating, which maintains and strengthens the weakly alkaline surface layer. A vicious circle of course.

Pedro DiNezio, one of the research’s co-authors and an affiliate scientist at the University of Texas Institute of Geophysics and an associate professor at the University of Colorado, said the discovery is “a powerful reminder that the world must reduce its CO2 emissions”. .” to avoid breaching this barrier and others. Whether it’s this or the collapse of the ice caps, there is potentially a series of connected crises that hide in our future and should be avoided at all costs. The next step is to determine if the alkalinity mechanism kicks in under more moderate emissions scenarios.”

Co-author Nikki Lovenduski, a professor at the University of Colorado who contributed to the Intergovernmental Panel on Climate Change’s 2021 climate report, reported that “the study’s findings will help scientists make better projections of future climate change. This document shows that the climate change problem it may seem exacerbated for things still unknown. But the ocean climate feedback mechanism revealed by this particular study will open new avenues of research that will help us better understand the carbon cycle past climate change and perhaps finding solutions to future problems,” he concluded.