Climate Change: getting shipping back on course
Simon Bullock, James Mason and Alice Larkin
Shipping’s progress on climate action seems as stuck as the Evergreen cargo ship in the Suez Canal. This blog, based on three pieces of research at the Tyndall Centre for Climate Change Research at Manchester, looks at what could set it heading in the right direction.
Meeting the Paris Agreement’s 1.5°C climate target means halving global carbon dioxide (CO2) emissions by 2030, and reaching net-zero by 2050. All sectors and countries need to play their part. International shipping is one of the major contributors; its heavy reliance on marine fuel oils means its emissions are similar to Germany or the whole of South America. But, rather than rising to the urgent challenge of the climate emergency by planning for deep emissions reductions, its current targets — set through the International Maritime Organisation (IMO) — can see emissions rising until 2030.
Clear destination
As CO2 remains in the atmosphere for centuries, it is cumulative emissions that determine the level of global warming, not just any zero-emission end date. Tyndall Research calculates the cumulative emissions budget for the shipping sector that allows it to make a fair contribution to giving a 50% chance of keeping warming to 1.5 degrees — the aim of the Paris Climate Agreement. Keeping to this emissions budget is equivalent to a linear reduction in emissions from now reaching 50% of 2008 levels by 2030, and then dropping to zero by 2040. By contrast, the IMO targets set in 2018 are equivalent to constant emissions until 2030, and only a 50% reduction by 2050. The IMO needs a radical change in course.
The other critical point from this analysis is that this course change is urgent. If the IMO delays strategy revision until 2025, then keeping to the same budget would mean getting to zero emissions by 2035 — and delivering such a transition in 10 years is not tenable.
Clear priorities
A great deal of attention in shipping is focused on delivering zero-carbon alternative fuels, such as hydrogen, ammonia and methanol. This is essential. However, it will require major new global bunkering infrastructure, progress on carbon pricing, and colossal rates of roll-out. It is expected that this will happen at scale from 2030. But is this enough?
To investigate this, Tyndall research looks at the “committed emissions” from existing ships in the EU. This accounts for the “lock-in” of existing high-carbon infrastructure that will continue to emit for years into the future. The research found that even with retrofitting these existing ships with zero-carbon fuels from 2030, they would consume over 100% of the entire carbon budget for EU shipping. Zero carbon fuels alone are therefore insufficient to tackle emissions to the scale that the climate emergency demands.
Although there is good news; the research found that additional action in the 2020s on energy efficiency measures can keep shipping’s emissions within Paris Agreement carbon budgets. Slow steaming, operational efficiencies, use of some sustainable biofuels and fitting wind-assisted propulsion technologies in the 2020s, in combination with zero carbon fuels in the 2030s, can deliver Paris-compatible emission trajectories for the shipping sector.
Getting moving
The third piece of research looks at one of those 2020 measures in detail: wind-assisted ship propulsion. This is a modern take on a very old bit of technology — using the power of the wind to propel ships. Brought into the 21st Century through advanced computational modelling techniques and the latest material science, Flettner rotors sails look nothing like classical sails, but instead use the Magnus effect to propel ships. Modelling of wind speeds across the Atlantic also enables the assessment of voyage optimisation, which combines optimal ship routes and speeds to deliver even greater carbon savings. The research found that deploying four Flettners rotors on a Panamax bulk carrier plying a North Atlantic route would cut CO2 emissions by 12%. Adding voyage optimisation increases the savings to 19%.
Sailing into port
This Tyndall Research has three main conclusions. First, for shipping to play a fair part in meeting the Paris goals, the IMO needs to substantially strengthen its existing 2030 and 2050 targets. The IMO should bring a revised set of targets to COP26, including a 50% cut on 2008 levels by 2030, and a zero-emission target of 2040. This is a 20-year transition — extremely challenging, but feasible. But it is critical that this target revision occurs soon. Every year of delay in setting new targets means bringing the zero-emission date two years earlier. Leaving revision to 2025 means a 2035 zero date — and a 10-year transition is too rapid to be feasible.
Second, this transition cannot rely solely on zero-carbon fuels. It is imperative that absolute emission reductions occur in the 2020s, and this requires major action on reducing energy use, particularly from existing ships, which will still dominate the global fleet even in 2030. There are multiple actions that are needed here: slow steaming, wind propulsion, operational retrofits. All would be facilitated by international and regional progress on carbon pricing for shipping.
Third, there is no one silver bullet, but many actions together can deliver the level of emissions reductions needed. Research on wind propulsion and voyage optimisation shows that this can deliver almost 20% savings — this is a huge contribution, and policy-makers and ship-owners should look to enable the rapid global roll-out of this technology on all routes where it is feasible.
Find out more about this research and watch the presentation via the Climate Exp0 media library.
Climate Exp0 is the first virtual conference from the COP26 Universities Network and the Italian University Network for Sustainable Development (RUS), sponsored by UK Research and Innovation (UKRI), Cambridge University Press, the Conference of Italian University Rectors (CRUI), and the 2021 UN Climate Change Summit (COP26).
Running from 17–21 May 2021, it takes place at a critical juncture in the COP26 pre-meetings and negotiations, and is part of the All4Climate Italy 2021 official pre-COP26 initiatives. Learn more and register your place via https://www.climateexp0.org.
