Sulfur dioxide produced by marine life is cooling the climate more than previously thought, especially over the Southern Ocean.
This was reported by the press service of the Institute of Marine Sciences (Spain).
It is noted that the discovery was made as a result of the first quantitative assessment of global sulfur production by marine life.
About 40 years ago, one of the most revolutionary hypotheses about the role of the ocean in regulating the Earth’s climate was proposed:
- she proposed that microscopic plankton living on the surface of the ocean produced sulfur in the form of a gas that, when released into the atmosphere, oxidized and formed tiny particles known as aerosols;
- aerosols reflect some of the sun’s radiation back into space, reducing the amount of heat the Earth retains—the opposite effect of greenhouse gases;
- The cooling effect of aerosols is enhanced because these particles are necessary for the condensation of water droplets and the formation of optically dense clouds. Clouds are the climatic element with the greatest cooling capacity.
A new discovery expands the understanding of marine sulfur’s influence on climate by adding a previously undetected compound.
Until now, we thought that the oceans released sulfur into the atmosphere only in the form of dimethyl sulfide, a planktonic residue that is mainly responsible for the characteristic odor of seafood, the scientists note. “Today, thanks to advances in instrumentation, we know that they also release methanethiol, and we have found a way to quantify on a global scale where, when and in what quantities this occurs.
To do this, the researchers collected all available measurements of this new compound, compiled those taken in the Southern Ocean and the Mediterranean coast, and statistically linked them with satellite temperature data.
This led them to conclude that methanethiol increases known marine sulfur emissions by 25% on average annually worldwide.
This may not seem like much, but methanethiol oxidizes and forms aerosols more efficiently than dimethyl sulfide, increasing its impact on the climate, the scientists note.
The researchers fed data on marine metanethiol emissions into a more modern climate model to assess their impact on the entire planet. It turned out that:
- the influence is much more pronounced in the Southern Hemisphere, where there are fewer continents and less human activity, as well as less sulfur from burning fossil fuels – this shows what the influence of the ocean on climate was before the industrial revolution;
- Including methaneol in the climate model means an increase in the formation of sulfur aerosols over the Southern Ocean by 30% – 70%, which reduces the incident solar radiation in summer by 0.3 – 1.5 W/sq.m. m.
Current climate models vastly overestimate solar radiation…mainly because they fail to model clouds correctly. Taking into account new sulfur emissions will make the model a little closer to reality, scientists note.
Scientists note that this discovery was further evidence that the oceans not only capture and distribute solar heat and absorb some of the carbon dioxide released into the atmosphere, but also produce gases and particles that have a direct climate impact.
Despite this, scientists note that the scale of the impact of human activity is such that the planet is warming and will continue to warm if nothing is done, the article notes.
Oceans a hundred years ago were warmer than thought due to measurement error – scientists (INFOGRAPHICS)
Source: Racurs
I am David Wyatt, a professional writer and journalist for Buna Times. I specialize in the world section of news coverage, where I bring to light stories and issues that affect us globally. As a graduate of Journalism, I have always had the passion to spread knowledge through writing.