Ships are using cleaner fuel to reduce air pollution, but at the expense of clouds’ ability to reflect sunlight into space.
The use of less polluting fuel by ships has fueled global warming, according to new research published in the journal Communications Earth and Environment on May 30. Accordingly, the transportation industry’s switch to using low-sulfur fuel from 2020 could cause the warming rate to double (or more) this decade, even contributing to record-breaking temperatures. continent in the past year.
The reason is that tiny particles in sulfur pollutants help reflect sunlight into space, making clouds more mirror-like, creating a temporary cooling effect on Earth. Scientists have also predicted that switching to cleaner fuels will reduce this reflection effect and speed up the warming process, although the extent is unclear.
In the new study, a team of experts combined satellite observations and simulations to estimate the climate impact of reducing sulfur in fuel under the International Maritime Organization (IMO) regulations that took effect in 2019. January 2020. Introduced to limit air pollution, the regulation has helped reduce sulfur dioxide emissions from the global shipping industry by 80%, according to Tianle Yuan, lead author of the study, a scientist at the Center NASA’s Goddard Space Flight.
But Yuan said this rapid decline also causes a “shock” effect on Earth, causing clouds to reduce their ability to reflect some of the sun’s energy back into space, leading to a warming planet. “Basically, the rate of warming will double in the 2020s,” he said.
This effect is not uniform globally, appearing to be stronger in the North Atlantic, leading to warmer sea surface temperatures. “It contributes to the abnormal warming the world experienced in 2023 and 2024. However, we cannot determine the exact extent,” Yuan said. The research team also could not conclude that this was the main cause.
2023 was the hottest year on record and this trend continued in 2024, with land and sea temperatures reaching new monthly highs. Human activity is the main cause of warming. However, scientists also consider other factors that may contribute to this unusual heat, such as El Nino, a periodic natural weather pattern in the Pacific Ocean.
New research also provides evidence that technology that injects particulate matter into clouds to increase heat reflection can help slow global warming somewhat. However, this technology is still controversial about its long-term impact on Earth.