Spills of ammonia as a shipping fuel could negatively impact certain habitats and species more than others and the industry should make sure it uses ammonia in a safe from the very beginning, according to a new joint study released by Environmental Defense Fund (EDF), Lloyd’s Register (LR) and Ricardo PLC.
The joint study examines the potential marine environmental impacts of ammonia spills during its use as a shipping fuel.
Ammonia generated from renewable energy is considered a sustainable alternative to fossil fuels as the shipping industry decarbonises.
The study, which used extensive modelling due to the scarcity of real-world data, focuses specifically on the impacts of large ammonia fuel spill scenarios on marine habitats.
Potential effects on aquatic environments and associated ecological receptors were assessed in scenarios if a spill were to occur during bunkering or in the case of a ship’s collision and sinking. In addition, possible mitigation measures and specific spill management practices for these scenarios were modelled and studied.
“The shipping industry must make a rapid energy transition to address the climate emergency. But it is also clear that we must proceed with caution. We owe it to future generations to ensure we are championing true climate solutions that will not negatively impact our rivers, our oceans or our health”, said Marie Hubatova, Director of Global Shipping for EDF’s Global Transport team.
The study found that estuaries, mangroves and wetlands are particularly sensitive to potential ammonia fuel spills compared to the polar regions and the deep sea. Within these habitats, it is typically fish which are most sensitive to an ammonia spill, with birds and mammals to a lesser degree.
The results were then compared to previously studied habitats and species’ sensitivity to conventional oil-based fuels. Overall, an ammonia spill has a relatively smaller dispersion distance and lower persistence within the environment when compared to heavy fuel oil (HFO) and marine gas oil (MGO).
While the maritime industry has prior experience with ammonia transported in gas carriers and used as a refrigerant, the introduction of ammonia as a shipping fuel creates new challenges related to safe bunkering, storage, supply and consumption for different ship types.
The potential toxicity of ammonia cannot be ignored; without mitigation measures and solid spill management practices, an ammonia fuel spill could have negative impacts on aquatic environments.
Therefore, a robust regulatory framework must be developed for ammonia to be a viable, low-carbon alternative for shipping, the report states.
“All future fuels come with specific challenges. We have been using oil to power ships for almost a century now and we had to learn how to do so in a safe way. We can’t go through the same process with ammonia”, said Hubatova. “We have to make sure we get it right from the very beginning. A robust regulatory framework and good management practices are essential for the safe use of ammonia.”
According to EDF, LR and Ricardo, this study presents the first look at ammonia’s potential ecological impacts as a fuel.
Further research is needed to evaluate the full range of ecological and health implications (especially to a ship’s crew) of ammonia, including the increased nitrogen deposition from chronic ammonia leakage and combustion by-products to determine its safety.