In the aftermath of the attacks against ships in the Red Sea, carriers and shipowners prioritised the safety and security of seafarers when they decided to avoid the Suez Canal and sail around Africa.

But their journeys could not escape the environmental cost.

The longer journeys - and sometimes higher speeds to meet schedules - have led to higher CO2 emissions.

Emissions from commercial ships

According to a study by Consultancy INVERTO, the extra fuel commercial ships burned in the past four months has resulted in an estimated 13.6 million tonnes of CO2 emissions.

This amount is equivalent to the emissions of approximately nine million cars over that same period.

While we need to take into consideration the role of extreme weather at sea, it is clear the Red Sea crisis adds another layer of complexity.

Container shipping emissions

Recent research estimated the increase so far per container based on container tracking technology, which helps companies calculate the carbon footprint of their supply chains.

Rerouted shipments have resulted in an average of 1.35 tons of CO2 emissions per container, as opposed to the 1.07 tons on the original route. 

As Reuters illustrates, "the extra emissions from a single ship carrying 10,000 containers on a rerouted journey would dwarf the Statue of Liberty."

Another report by Xeneta shows that emissions of container ships sailing from Asia to the Mediterranean increased by 63% in the last quarter compared to Q4 of 2023.

Vessel tracking data reveal that more than 600 ships have been diverted since the attacks began last year.

As the political situation in the region remains unsolved, carbon emissions are only expected to increase, especially with carriers adding more capacity to cope with container shortages.