Scientists warn: Cleaner Shipping Fuel Contributes to Ocean Warming
Scientists Warn of Unintended Consequences: Shipping Fuel Regulations Impact Ocean Temperatures
Shipping fuel regulations introduced in 2020 have significantly reduced sulfur dioxide (SO2) pollution but may have inadvertently increased ocean temperatures by diminishing cloud cover, according to a recent modeling study reported by Azernews.
The International Maritime Organization (IMO) mandated that shippers lower their fuel sulfur content from 3.5% to 0.5%, resulting in an 80% decrease in SO2 emissions, as found by a research team led by Tianle Yuan at the University of Maryland, as reported by Al Arabiya.
While SO2 is a major pollutant, it also plays a role in cooling the planet by creating aerosols that enhance cloud brightness and reflect sunlight away from the Earth.
The IMO fuel standards might be responsible for 80% of the planet’s net heat uptake since 2020, particularly in busy shipping lanes, according to the study published in the journal Communications Earth & Environment.
Climate scientists have linked the reduction of SO2 to record ocean temperatures last year. Some suggest that reducing air pollution globally could have hastened global warming.
“The cooling effect of SO2 is well understood, as documented in the aftermath of several major volcanic eruptions over the past 2,000 years,” noted Stuart Haszeldine, director of the Edinburgh Climate Change Institute at the University of Edinburgh. Although not involved in the study, Haszeldine highlighted the significant and concerning trend of rising temperatures.
However, some experts believe the study may overstate the impact of the IMO policy. Joel Hirschi from Britain’s National Oceanography Centre commented, “Research into why recent temperatures have been so high is ongoing, and the reduced sulfur content in ship fuel is only one contributing factor.”
The researchers suggested that “marine cloud brightening” could be a potential geoengineering solution to global warming. Scientists have been exploring various methods to reflect heat back into space, though proposals to inject SO2 into the atmosphere remain controversial. Other experiments have investigated spraying seawater into the air to thicken clouds.
