Black Carbon

Black carbon is the sooty particulate fraction of incomplete fuel combustion, a short-lived climate forcer that accelerates ice melt when it deposits on snow, which makes it a particular concern for Arctic shipping. The IMO has addressed it through the PPR sub-committee since 2011 but has set no mandatory emission limit; a 2021 resolution (MEPC.342(77)) urges ships to use distillate or cleaner fuels in or near the Arctic to cut black carbon. Distillate fuels and particulate filters reduce it relative to residual heavy fuel oil.