Researcher Sees IMO 2020 Indirectly Causing 323 Million MT/Year CO2 Emissions Increase

by Ship & Bunker News Team
Monday April 18, 2022

The IMO 2020 transition may have indirectly led to an increase in global CO2 output of as much as 323 million mt/year, or almost a third of the shipping industry's carbon footprint, according to a recently published paper.

The paper was published in the Elsevier journal Transportation Research, and tracks the indirect CO2 emissions caused by the IMO 2020 transition. Rather than just comparing the shift from HSFO to VLSFO, the research takes a wider look at the increased crude oil run rates at refineries that were caused by the transition.

Ship & Bunker first reported on this research in 2016, and the work has now been scientifically reviewed and updated with IEA and EIA data on run rates in 2020.

"Several of the comparing assessments of CO2 emissions when switching from VLSFO to HSFO are flawed, since they do not account for product added value," Gustav Krantz, a lead researcher on the paper, told Ship & Bunker.

"Refining output of products with negative share of added value are already minimised, with the consequence that refiners increase crude oil throughput to meet the new demand."

Krantz and his co-authors look at the increased demand for high-value refined products -- mostly middle distillates -- caused by the need to produce VLSFO rather than HSFO for the shipping industry, and how that demand has been met more by increasing crude throughput at refineries rather than through upgrading of low-value refined products into high-value ones.

Those increased run rates have delivered a higher output of all oil products, The research assumes that all oil products will be oxidised from a long-term perspective, which is equivalent to an increase proportional to the increase in refinery runs.

The total increase in emissions from 2019 to 2020 found using this model could be as high as 323 million mt/year of CO2 equivalent, according to the paper. That compares with total shipping emissions of 1.076 billion mt in 2018, according to the IMO's fourth GHG study.

The research uses forecasts for 2020 run rates rather than real data, so the COVID-19 effect will mean 2020's numbers were lower in reality, but a similar increase is likely to emerge in the following years as demand recovers.

"It's quite a dramatic change, and we haven't discovered this or even noticed it with the methodology used to anticipate the effects of IMO 2020," Krantz said.

To read the full report, click here.