Uploaded October 2025 | Updated September 2026, 3 weeks ago
Global shipping contributes about 3% of global greenhouse gas emissions, equivalent to the total emissions of Japan or Germany. The sector, including its contribution to climate change, is governed by the International Maritime Organisation or the IMO, which is a UN agency based in London in the United Kingdom.
Last week, the International Maritime Organisation gathered to vote on a proposal to reduce emissions from ships that had been agreed to in principle earlier this year. And ahead of the gathering, most people intimately involved in the process thought the proposal would pass. But that wasn’t the case. The US stepped in at the last minute and pressured all those gathered to delay the vote on the proposal for another 12 months.
This week on Cleaning Up, host Bryony Worthington sits down with Professor Tristan Smith, a leading expert on shipping decarbonisation from UCL Energy Institute, to unpack the dramatic events at the latest International Maritime Organization meeting — where the United States’ last-minute intervention derailed a landmark vote on cutting emissions from ships.
Together, they explore:
• How global shipping, responsible for around 3% of greenhouse gas emissions, became a critical test case for international climate policy
• Why the IMO’s proposed carbon intensity regulation could have marked the beginning of the end for oil and LNG as marine fuels
• The “Tariff diplomacy” and other threats that reshaped global negotiations
• What this means for COP30 and other multilateral agreements.
Bryony and Tristan also dive deep into possible solutions: from e-fuels, ammonia, and battery electrification to nuclear propulsion — weighing what’s practical, what’s political, and what’s merely wishful thinking.
Leadership Circle:
Cleaning Up is supported by the Leadership Circle, and its founding members: Actis, Alcazar Energy, Davidson Kempner, EcoPragma Capital, EDP of Portugal, Eurelectric, the Gilardini Foundation, KKR, National Grid, Octopus Energy, Quadrature Climate Foundation, SDCL and Wärtsilä. For more information on the Leadership Circle, please visit https://www.cleaningup.live.
Links and more:
• Is Shipping the Easiest "Hard-to-Abate" Sector? - Ep143: Johannah Christensen -- youtube.com/watch?v=umPAonV20cM
• The IMO website: imo.org
• Michael’s Substack on the IMO decision: mliebreich.substack.com/p/imo-members-choose-between-the-us
Chapters:
00:00 - Coming Up
01:21 - Introduction
04:30 - Shipping Emissions
07:07 - What is the IMO?
12:30 - What Was Being Negotiated?
18:00 - What Happened?
21:00 - When Did The US Change It's Mind?
23:30 - Ugly Diplomacy
26:00 - What This Means For COP30
28:45 - The Future of LNG Shipping
33:25 - Regional Regulation
37:00 - Is the IMO Dead?
38:00 - New Tech vs Green Fuels
41:00 - Nuclear Shipping
45:00 - Should We Pause The Treaty?
50:30 - Are Fuels Too Expensive?
56:30 - Should We Use Renewable for Shipping Fuels?
01:01:45 - Tax on Shipping Fuels
01:04:30 - A New Treaty?
01:06:57 - Sulfur Regulations
01:10:00 - Geoengineering and Risk
01:14:17 - Outro
Global shipping contributes about 3% of global greenhouse gas emissions, equivalent to the total emissions of Japan or Germany. The sector, including its contribution to climate change, is governed by the International Maritime Organisation or the IMO, which is a UN agency based in London in the United Kingdom.
Last week, the International Maritime Organisation gathered to vote on a proposal to reduce emissions from ships that had been agreed to in principle earlier this year. And ahead of the gathering, most people intimately involved in the process thought the proposal would pass. But that wasn’t the case. The US stepped in at the last minute and pressured all those gathered to delay the vote on the proposal for another 12 months.
This week on Cleaning Up, host Bryony Worthington sits down with Professor Tristan Smith, a leading expert on shipping decarbonisation from UCL Energy Institute, to unpack the dramatic events at the latest International Maritime Organization meeting — where the United States’ last-minute intervention derailed a landmark vote on cutting emissions from ships.
Together, they explore:
• How global shipping, responsible for around 3% of greenhouse gas emissions, became a critical test case for international climate policy
• Why the IMO’s proposed carbon intensity regulation could have marked the beginning of the end for oil and LNG as marine fuels
• The “Tariff diplomacy” and other threats that reshaped global negotiations
• What this means for COP30 and other multilateral agreements.
Bryony and Tristan also dive deep into possible solutions: from e-fuels, ammonia, and battery electrification to nuclear propulsion — weighing what’s practical, what’s political, and what’s merely wishful thinking.
Leadership Circle:
Cleaning Up is supported by the Leadership Circle, and its founding members: Actis, Alcazar Energy, Davidson Kempner, EcoPragma Capital, EDP of Portugal, Eurelectric, the Gilardini Foundation, KKR, National Grid, Octopus Energy, Quadrature Climate Foundation, SDCL and Wärtsilä. For more information on the Leadership Circle, please visit https://www.cleaningup.live.
Links and more:
• Is Shipping the Easiest "Hard-to-Abate" Sector? - Ep143: Johannah Christensen -- youtube.com/watch?v=umPAonV20cM
• The IMO website: imo.org
• Michael’s Substack on the IMO decision: mliebreich.substack.com/p/imo-members-choose-between-the-us
Chapters:
00:00 - Coming Up
01:21 - Introduction
04:30 - Shipping Emissions
07:07 - What is the IMO?
12:30 - What Was Being Negotiated?
18:00 - What Happened?
21:00 - When Did The US Change It's Mind?
23:30 - Ugly Diplomacy
26:00 - What This Means For COP30
28:45 - The Future of LNG Shipping
33:25 - Regional Regulation
37:00 - Is the IMO Dead?
38:00 - New Tech vs Green Fuels
41:00 - Nuclear Shipping
45:00 - Should We Pause The Treaty?
50:30 - Are Fuels Too Expensive?
56:30 - Should We Use Renewable for Shipping Fuels?
01:01:45 - Tax on Shipping Fuels
01:04:30 - A New Treaty?
01:06:57 - Sulfur Regulations
01:10:00 - Geoengineering and Risk
01:14:17 - Outro
