Assessment of climate alignment
Under the Poseidon Principles, Signatories will calculate the climate alignment of their shipping portfolio relative to established decarbonization trajectories.
Signatories will, on an annual basis, measure the carbon intensity and assess climate alignment – carbon intensity relative to established decarbonization trajectories – of their shipping portfolios.
Assessing climate alignment
The Poseidon Principles use carbon intensity relative to established decarbonization trajectories to measure climate alignment.
Climate alignment is defined as the degree to which a vessel, product, or portfolio’s carbon intensity is in line with a decarbonization trajectory that meets the IMO ambition of reducing total annual GHG emissions by at least 50% by 2050 based on 2008 levels.
The Poseidon Principles rely specifically on the Annual Efficiency Ratio (AER) as the carbon intensity metric. The AER uses the parameters of fuel consumption, distance travelled, and design deadweight tonnage.
To assess climate alignment of a single vessel, the vessel’s annual carbon intensity is compared with the decarbonization trajectory for its ship type and size class. The climate alignment of a product and or portfolio is a weighted average of the vessel carbon intensities in each product or portfolio.
What is a decarbonization trajectory?
A decarbonization trajectory is a representation of how many grams of CO2 a single ship can emit to move one tonne of goods one nautical mile over a time horizon. To assess climate alignment of a single vessel, the vessel’s annual carbon intensity is compared with the decarbonization trajectory for its respective ship type and size class.
Standard decarbonization trajectories are produced by the Secretariat of the Poseidon Principles for each ship type and size class.