NASA AI shows slashing sulfur in shipping fuel cut air pollution at sea
"Ship-track density experiences strong reductions in every detected major shipping lane compared to climatology and reaches record lows in the nearly 20-year data record," the paper states.
"Except the trans-Pacific and trans–North Atlantic shipping lanes, other shipping lanes are not discernible any longer. Annual mean ship-track density decreases by 50 percent or more in five major shipping lanes compared to the climatological mean. The decline is even steeper if compared to 2019." Global shipping traffic fell by 1.4 percent for a few months during the COVID-19 pandemic and remained low in 2021, though those fewer vessels did not account for the large drop in detected shipping tracks. The researchers believe the IMO 2020 fuel regulation had a larger impact in reducing air pollution.
They also managed to trace popular shipping routes across Asia and America at different times – such as the drop in global trade following the 2008 financial crisis. There were two other dips in shipping traffic in Asia between 2014 and 2016 when China was importing and exporting less resources. "Ship tracks are great natural laboratories for studying the interaction between aerosols and low clouds, and how that impacts the amount of radiation Earth receives and reflects back to space," Yuan said."That is a key uncertainty we face in terms of what drives climate right now." ®