Reducing emissions is said to increase ocean warming

From January 1, 2020, sulfur content in marine fuel may be 0.5 percent instead of earlier 3.5 percent. This has resulted in an 80 percent reduction in sulfur dioxide emissions in international shipping. This action should benefit people’s health and cause fewer heart attacks, asthma attacks, lung cancer or other diseases.

A study published by “Communications Earth & Environment” now says the move has serious side effects. It says that reduced sulfur emissions could darken the clouds.

As a result, solar radiation absorbed by the world’s oceans increased by 0.2 watts per square meter, the study continues. This process is most likely responsible for the increase in temperature in the oceans from March 2023 onwards.

Reto Knutti is a climatologist at ETH Zurich. Compared with “Tages-Ancigar” He thinks the results of the study can be seen as plausible. Other possible factors, such as the strength of the Sun or the volcanic eruption of Hanga Tonga-Hanga Hapai, are not expected to contribute much to the thermal anomaly in 2023. “Here we see the first truly quantitative calculations,” says Nutty.

However, other experts not involved in the study are skeptical. “Caution is advised,” Anders Levermann from the Potsdam Institute for Climate Impact Research (PIK) told the German Press Agency (dpa). If you look at an effect over a short period of time, it is generally more prone to errors than over a longer period. From 2020 the share of stored thermal energy may be less than 80 percent. “Value in modeling may be overestimated.” Other factors may also be decisive for the record values ​​observed last year.

“In fact, why the last twelve months have been so unusually warm on the global average, well above the norm,” said Niklas Höhne, University of Wageningen in Berlin and the Nuclimat Institute for DBA. The main culprit is clearly the ever-increasing emissions of greenhouse gases. “But the additional effect has not been previously described.”

As a result of reduced shipping emissions, the long-term average rate of warming is expected to more than double this decade, according to the study.

“A new equilibrium will be reached” only after seven to 10 years, says Tianle Yuan, one of the authors. “That would accelerate our warming progress towards 1.5 degrees Celsius.”