Researcher: the climate could be cooled by using sulfur-rich fuel in ships

Atmospheric researcher and academic Markku Kulmala He has published with his colleagues from the University of Helsinki In the Tellus science journal his own proposal, how the climate could be modified to be cooler.

Most research has been done on spreading sulfur into the stratosphere, where the particles would reflect sunlight back into space. The Finnish group believes they have come up with a better version of the same idea.

Is it worth starting climate modification already?

I hope there will never be a situation where we have to send stuff into the stratosphere on a large scale.

I am currently of the opinion that it needs to be studied much more intensively and in a more diverse way than has been done so far. It’s worth thinking and exploring new ideas that are perhaps safer than the previous ones. However, it’s a different question at what point you should start using them.

What is your cooling suggestion?

We have noticed that organic substances are able to form new particles at minus 50 degrees. In other words, when monoterpenes or isoprene are injected into the upper atmosphere, they form particles there just like sulfur.

Monoterpenes and isoprenes would be oxidized there, just as sulfur is oxidized, creating compounds that form new particles.

These continue to react, grow and eventually form large particles capable of reflecting sunlight back into space.

What’s the advantage of doing the trick with organic particles?

According to our research, organic particles are less harmful than sulfur. Sulfur particles are associated with the risk that they can destroy the ozone layer, which protects the Earth from ultraviolet radiation. Sulfur may also rain as acid rain on the ground or in the lower atmosphere, polluting the air.

As the organic matter grows and the chemical reactions continue, the particles eventually evaporate, leaving only carbon dioxide and water. Carbon dioxide is produced so little that it has no significant effect on global warming.

The effect on ozone depletion is not yet known. That’s one thing we need to explore more. But according to preliminary results, the effect is much longer than sulfur.

Why do particulate matter consume ozone?

There is very strong ultraviolet radiation in the stratosphere, which produces hydroxyl radicals formed by oxygen and hydrogen.

Both hydroxyl radicals and ozone consisting of three oxygen atoms participate in the oxidation reactions that form small particles in the upper atmosphere.

We need to find out more about this whole thing before taking action.

In the environmental world, great things have often been invented, which have later turned out to be disasters. One example is CFCs, which caused the ozone hole.

Is the particle shadow enough to protect the atmosphere?

No, but in any case you have to take carbon dioxide out of the atmosphere. Its concentrations have become far too high. Now there is 430 ppm of carbon dioxide in the atmosphere, and the amount is increasing at the current rate of one hundred ppm in three decades.

When we go to 700 ppm and above, people start to experience physiological consequences. It is known that people and animals get tired if there is too much carbon dioxide in the indoor air. Indoors, we already easily exceed a thousand ppm.

If the carbon dioxide in the outdoor air increases too much, the ventilation is no longer sufficient to freshen the indoor air.

What kind of cooling effect would the particles have?

If a large part of the radiation can be reflected back, climate change will slow down and warming will stop.

Nevertheless, it is essential to get carbon dioxide emissions down and carbon sinks up.

Otherwise, the cooling of the atmosphere must be continued all the time. If the cooling is stopped, the atmosphere warms up again in an instant and a lot.

You have suggested returning sulphurous fuels to ships – why?

According to various results, the atmosphere has warmed by about 0.1–0.5 degrees because sulfur has been reduced from the atmosphere. The fork is big, but if the likely number is around 0.3 degrees, that’s a surprising amount. In arctic regions, it affects the most.

In winter, clouds warm the atmosphere and in summer they cool it. Therefore, summer clouds could be increased in northern sea areas. It could be enough for the ships to have fuel with a higher sulfur content in the summer.

The sulfur dioxide from the emissions turns into sulfuric acid in the atmosphere, which forms new small particles, which in turn add cloud droplets to the clouds.

In this way, the clouds would reflect more radiation back into space. The idea is originally Risto Isomäki.

Weren’t sulfur-containing fuels abandoned because of health hazards?

Yes. Particles are harmful near population centers. Far from human settlements in the Atlantic or the Arctic Ocean, there are practically no health hazards.