A ban on the dirtiest and most climate-damaging fuel for ships has come into effect in Arctic waters. Heavy Fuel Oil (HFO) is a tar-like, thick but relatively cheap oil that is widely used in shipping around the world, especially tankers, the BBC reported.

However, HFO is particularly damaging in the Arctic, where the black carbon it emits when burned speeds up the melting of snow and ice.

Campaigners say the ban, while welcome, will make little immediate impact as a series of loopholes will allow the vast majority of ships to use the fuel until 2029.

Photo: Getty

Produced from the waste left over in oil refining, HFO poses a huge threat to the oceans in general but to the Arctic in particular.

This sludge-like fuel is almost impossible to clean up if a spill occurs.

In colder waters, experts say, the fuel does not break down but sinks in lumps that linger in sediments, threatening fragile ecosystems.

In climate terms, this oil is seen as particularly dangerous, not just producing large amounts of planet-warming gas when burned, but also spewing out sooty particles called black carbon.

The oil was banned from use or transport in the Antarctic in 2011.

Environmentalists have been pushing to expand that restriction to northern waters for years, finally persuading the countries that participate in the International Maritime Organisation (IMO) to enact a ban back in 2021.

The restriction now comes into force in Arctic waters – and while campaigners agree this is progress, they believe there are far too many loopholes that will limit the impact.

According to the regulations, ships that have a “protected fuel tank” will be exempt from the ban.

Countries that border the Arctic will also be able to exempt their own ships from the ban in their own territorial waters.

The ban has many loopholes say campaigners, meaning ships with protected fuel tanks, like many tankers, will be able to continue to use Heavy Fuel Oil.

Some observers believe that increased efforts to extract oil in the Arctic could see a rise in the amount of HFO in use in these waters, instead of a decrease.