Shipping emissions can drop over 95% by 2050 with policy support, report says

International shipping can reach zero or very near zero tank-to-wake (TTW) CO2 emissions by 2050, and achieve 95%+ reductions in well-to-wake (WTW) greenhouse gas (GHG) emissions from 2018 levels, in scenarios aligned to a 1.5°C global temperature goal, according to a report from ERM, UMAS and UCL, commissioned by the UK Department for Transport as part of the evidence base for maritime decarbonization policies.

As disclosed, the study used UMAS’ Global Maritime Transport Model to assess the relative costs and potential impacts of technology transitions within international shipping under three core scenarios.

Scenario A makes steady reductions in TTW CO2 emissions starting from 2025, Scenario C delays until 2030 and then makes rapid, deep cuts to achieve the same cumulative TTW CO2 emissions, whereas Scenario B makes rapid cuts from 2025-2035 to achieve 10% lower cumulative TTW CO2 emissions, UMAS claimed, noting that in all core scenarios, international shipping achieves zero or near-zero TTW CO2 emissions by 2050 at the latest, along with 95-98% reductions in WTW GHG emissions from 2018 levels.

As per UMAS, cumulative costs vary – with each year of delay in the start of emission reductions, a further $100 billion is reportedly added to the total cost of decarbonization. Delaying the start of shipping decarbonization, even to 2030, is said to result in a more disruptive change in technology, including greater scrappage of vessels and a higher total cost for the transition.

It is understood that the lowest total cost pathway involves the widespread use of low-carbon ammonia; however, other fuel options, such as low-carbon methanol and hydrogen, could achieve a similar fleet decarbonization outcome but at a higher cost.

In the core scenarios, demand for low-carbon ammonia grows rapidly from the end of the 2020s, and by the 2040s, it is the major fuel used in the shipping sector, UMAS said, stressing that to meet this level of ammonia demand, current global ammonia production capacity would need to quadruple by the 2040s, with year-on-year growth rates close to or exceeding historical record growth rates. As reported, this can only happen if action to unlock investment is taken urgently, which relies on rapid agreement of the underpinning policy frameworks.

“A combination of measures and the use of carbon revenues may be important. Moreover, policies that only focus on tank-to-wake (TTW) CO2 emissions can incentivise solutions such as Liquefied Natural Gas (LNG), which has significant upstream and non-CO2 GHG emissions. There is an urgent need to modify policy to use well-to-wake (WTW) GHG emissions, and increase policy stringency to accelerate the take-up of vessel efficiency measures,” UMAS noted.