A joint study released by Environmental Defence Fund (EDF), Lloyd’s Register (LR) and Ricardo PLC, observed the potential marine environmental impacts of ammonia spills during its use as a shipping fuel
The study examined potential ammonia fuel spills during bunkering and collision scenarios, under a variety of conditions, including time of day, temperature, humidity and solar radiation. The outputs were tested across eight habitats (rivers, estuaries, wetlands, coastal waters, coral reefs, mangroves, polar regions and the deep sea) using multiple ecological receptors (bacteria, plankton, macrophytes, invertebrates, fish, birds, reptiles, and marine mammals).
“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 results found that estuaries, mangroves and wetlands were 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.
Lauren Dawson, senior consultant, Water and Environment Practice, Ricardo, said, “Examining the impact of ammonia is a challenge because of the vast conditions a ship might face while at sea or even when bunkered. Critical factors to consider include the various ship and storage types, the underlying principles which determine the fate of ammonia in the environment, and the diversity of aquatic habitats and species that could be affected. Ultimately, what we found is that ammonia is more threatening to fish species, and particularly to ecosystems with less saline water and higher temperatures.”
Existing reports indicated that oil-based fuels have higher impacts on invertebrates and birds, compared with ammonia. Ammonia has a medium impact on all other ecological receptors, except bacteria, whereas oil-based fuels have medium impacts on plankton, fish, macrophytes, reptiles and marine mammals.
While the maritime industry has prior experience with ammonia transported in gas carriers and used as refrigerant, the introduction of ammonia as a shipping fuel creates new challenges related to safe bunkering, storage, supply and consumption for different ship types.
“There are many questions around the use of ammonia as a shipping fuel. Studies like this support the industry’s understanding of the environmental impacts as well as the operational and safety challenges. Greater clarity about the risks posed to marine ecosystems will allow industry stakeholders to make better informed decisions on the multiple transition pathways under consideration,” said Andy Franks, senior risk specialist, LR Maritime Decarbonisation Hub.
Depending upon its safety, ammonia produced with renewable energy is already projected as one of the possible main future fuels of shipping. It is estimated that maritime shipping emits approximately 1,056mn tons of carbon dioxide per annum and is responsible for nearly 3% of global greenhouse gas emissions.