Mitigating In-Use Methane Emissions during Maritime Transportation Operations: A Policy Analysis
Abstract
Liquefied natural gas (LNG) as a fuel for maritime transportation has several benefits. LNG combustion for marine propulsion results in reductions of up to 95% for nitrogen oxides (NOx) emissions, ~100% for sulfur oxides (SOx) emissions and 30% for carbon dioxide emissions, compared to conventional marine heavy fuel oil, in terms of tank-to-propeller emissions. As a result, LNG-powered vessels are considered one option for achieving the International Maritime Organization (IMO) NOx and SOx regulations, and are increasingly being adopted by fleets worldwide. However, in terms of life-cycle greenhouse gas (GHG) emissions reductions, LNG's impacts are less clear. One of the main challenges of using LNG as a fuel is methane (CH4) slip or unburnt in-use CH4 emissions from exhaust streams. Without careful management of such emissions, LNG-powered marine vessels may release higher GHG emissions than their diesel counterparts. In light of the IMO's long-term goals to reduce both shipping-related air pollutants and GHGs, it is critical that CH4 slip in LNG-powered vessels is reduced as the marine shipping industry works towards full decarbonization.
This work aims to identify and evaluate potential policy incentives (market, non-market, regulatory, non-regulatory) for reducing CH4 slip from LNG-powered vessels. Currently, no policies for controlling CH4 slip from marine vessels are in place globally. We explore how new measurement tools may enable different policy instruments, either through real-time measurement and monitoring or identification of best available technology and environmental practices. To identify and assess potential policy instruments, we draw policy ideas from existing air pollution and GHG emissions reduction policies from the shipping and the transportation sector, and use a combination of a systematic review methodology and multi-stakeholder interviews. We also apply systematic review protocols to identify and analyze operational and technological measures for reducing CH4 slip. We evaluate potential policy instruments on factors such as administrative feasibility, economic efficiency, effectiveness, stakeholder acceptability, policy robustness, and policy consistency; and use stakeholder interviews to better understand potential policy trade-offs and complementaries.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMGC0850015L
- Keywords:
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- 1610 Atmosphere;
- GLOBAL CHANGE;
- 1631 Land/atmosphere interactions;
- GLOBAL CHANGE;
- 1694 Instruments and techniques;
- GLOBAL CHANGE;
- 1875 Vadose zone;
- HYDROLOGY