Misleading to claim shipping regulations that cut sulphur emissions and increased temperatures disprove human-caused global warming
IN SHORT: Contrary to claims on social media, a June 2024 study about global shipping regulations and increasing temperatures is not proof that human activities do not influence the Earth's climate.
A study published in early June 2024 in the Nature Communications journal Earth & Environment suggests that global shipping regulations introduced in 2020 to cut polluting emissions from ocean-going ships by 80% caused higher temperatures across the world in 2023.
The study's results were widely reported by news media across the world.
But it was quickly seized upon by climate change deniers as some kind of proof that human-caused global warming is a hoax or doesn't exist.
"Almost All Recent Global Warming Caused by Green Air Policies - Shock Revelation From NASA," reads a common claim circulating on Facebook.
The Facebook page Climate change is natural had this to say:
The world of climate science is in shock following extraordinary findings from a team of high-powered NASA scientists that suggest most of the recent global temperature increases are due to the introduction of draconian fuel shipping regulations designed to help prevent global warming. The fantasy world of Net Zero is of course full of unintended consequences, but it is claimed that the abrupt 80% cut in sulphur dioxide emissions from international shipping in 2020 has accounted for 80% of global warming since the turn of the decade.
The post includes the hashtag #CostOfNetZero and a link to a Daily Sceptic article that repeats the claim, as well as a graphic with the words "Net Zero Watch".
Sign up for free AllAfrica Newsletters
Get the latest in African news delivered straight to your inbox
The claim also appears on the notorious disinformation site The People's Voice. Over the years, fact-checkers have had to continually debunk claims made by this website.
But the study is actually more proof of the influence human activities have on the Earth's climate. Here's why.
Sulphur dioxide cools the planet, not a 'net zero' atmospheric gas
The study found that the 2020 regulations drastically cut emissions of sulphur dioxide from ships. Sulphur dioxide is a global cooling gas.
The UK Guardian explains:
Until 2020, global shipping used dirty, high-sulphur fuels that produced air pollution. The pollution particles blocked sunlight and helped form more clouds, thereby curbing global heating. But new regulations at the start of 2020 slashed the sulphur content of fuels by more than 80%.
Climate scientists have warned for years that cutting sulphur emissions may contribute to global warming.
And "net zero" policies apply to the global warming or "greenhouse" gas carbon dioxide. The policy is to reduce the amount of human-caused carbon in the atmosphere until it reaches the level it would have been without human activity.
The net zero initiative does not apply to sulphur dioxide.
Climate change is complex, and not all atmospheric gases are the same.
