The Covid-19 pandemic caused a drastic change to energy consumption patterns worldwide and highlighted transport’s impact on the climate crisis. In 2020, carbon dioxide emissions fell by 6.4% to 2.3 billion tonnes of carbon dioxide. While a portion of this decrease can be attributed to industrial slowdowns, the clamp-down on commercial flights and the disruption to shipping supply chains also contributed substantially to this decrease.
Transport is an underplayed contributor to the climate crisis
According to the World Resources Institute, energy consumption accounted for 73.2% of global greenhouse gas emissions in 2020. Of this total, transport accounted for 16% of emissions. Road transport dominates total transport emissions (73%), while aviation and shipping contribute 12% and 11%, respectively. The increasing popularity of electric vehicles will see road transport’s contribution to carbon emissions decrease significantly. In fact, according to GlobalData subsidiary LMC, increasing demand will see EVs account for 50% of car sales in 2034. However, little progress has been made toward decarbonizing the aviation and maritime sectors.
Aviation and maritime were omitted from the 2015 Paris Climate Change Agreement but are now subject to bold emission reduction targets. For example, the International Civil Aviation Organization, a UN agency, has stated that commercial aviation must reach net zero by 2050. Meanwhile, the International Maritime Organization has set the aim of halving emissions by 2030, ideally reaching net zero by 2040. To meet these reduction targets, both sectors will need to rapidly ramp up their emission reduction efforts and engage with a combination of energy transition technologies.
Turnkey technologies for decarbonisation
Electrification, biofuels, hydrogen, and carbon capture and storage (CCS) are all technologies that could be used to decarbonise the aviation and maritime sectors. Electrification would provide higher rates of efficiency than hydrocarbon fuel and provide the opportunity to substitute renewable energy into these two heavily polluting sectors. Alternatively, biofuels are formed through the processing of organic material and can be blended with existing fuel or used to create net-zero fuels. Biofuels are also compatible with many aircraft and ships that are already in service, meaning that they can provide immediate decarbonization with limited retrofitting required. For example, all Airbus aircraft are certified to fly with up to 50% safe aviation fuel (SAFs), a type of biofuel.
Hydrogen fuel cells have great decarbonisation potential. Requiring just hydrogen and oxygen, the process produces water and electricity as its only products, although it does carry pipeline emissions associated with the hydrogen’s production when renewable energy is not used. Lastly, by transforming carbon dioxide into a liquid or solid compound, CCS provides a way of capturing point source emissions, so it is highly applicable to aircraft and ships. This approach could also be used to offset each industry’s emissions by tackling the carbon that has already accumulated in the atmosphere.
While all these energy transition technologies hold potential, there are several practical challenges to their implementation. For example, the electrification of aviation is hampered by the struggle to achieve high energy densities while not increasing the weight of batteries, which increases the overall energy requirements. As a result, current electric flights are restricted to only short journeys. Similarly, biofuel production remains low, which is creating a cost barrier to aviation and maritime players adopting this technology. The lower energy per unit of volume of hydrogen will also require larger or cryogenic fuel tanks, which will demand a redesign of many ships and aircraft. In addition, the high cost of raw materials such as iridium, which is used as a catalyst in hydrogen production, will create a further cost barrier to adoption. Likewise, although some less energy-intensive methods for CCS are being developed, high energy requirements will also make this technology’s adoption costly.
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Winds of change
Despite these challenges, some companies are making progress. For example, in 2022 Airbus launched its ZeroE demonstrator program, which aims to use hydrogen to power an A380 MSN1 and create a zero-emission flight by 2035. London-based start-up, Seabound, has also developed a CCS solution that can be fitted to ships to reduce emissions by 95%. The firm has plans to go commercial with its solution in 2024. The aviation and maritime sectors are preparing to take the first steps in their energy transition. However, both sectors must play a game of catch-up if they are to meet their ambitious net-zero targets.