The science on tackling climate change is simple: zero out carbon dioxide emissions and global temperatures will stabilize. But a carbon accounting quirk might mean that, even if all countries meet that goal, pollution from shipping and aviation could result in continued warming.
The peculiarity exists because the current United Nations accounting system is focused on emissions generated within a country’s territorial boundaries. Ships and planes that emit CO2 outside the jurisdiction don’t usually get counted.
That’s a problem worth fixing. Steffi Lemke, Germany’s environment minister, thinks this year’s annual UN climate summit COP28 could provide a solution. In a speech at the Petersberg Climate Dialogue in May, Lemke said it is possible to “fully map these emissions” and therefore individual countries should account for them in the summit’s “global stocktake,” which will measure how nations are doing in achieving the goals set under the Paris Agreement. The details on how countries account for shipping and aviation emissions would be up for negotiation.
CO2 emissions from shipping and aviation accounted for roughly 5% of the global total in 2021. Both are expected to grow under business-as-usual scenarios, with aviation expected to at least double in its absolute contribution to the warming problem. That means there’s no way to meet global climate goals without including these sectors under the net zero framework.
In a written response to Lemke’s proposal, the COP28 team said that the global stocktake is a process led by UN members party to the Paris Agreement and it welcomes “all opportunities” to achieve climate goals. However, it added that “international shipping and aviation are not part of the negotiated outcomes under” the deal.
That’s not how the European Commission reads the document that was signed in 2015. An EC spokesperson pointed out that the Paris text refers to all “anthropogenic emissions” — or human-caused greenhouse gas pollution — which the bloc sees as including the shipping and aviation industries.
Europe’s push to count those emissions will be backed by new targets. The EU’s latest climate legislation includes targets to cut emissions from international shipping and aviation. The bloc will account for emissions from ship and plane journeys that end in or originate from its territory. And the EC spokesperson added that the European Union will include the targets on those emissions when it submits revised goals to the UN soon.
The assessment is backed by analysis from non-profit Transport & Environment (T&E) that found the Paris Agreement “imposes legal obligations” on member states to count international aviation and shipping. COP28’s stance is “factually untrue,” said Jacob Armstrong, shipping expert with T&E. A spokesperson for COP28 acknowledged that, “while shipping and aviation emissions are anthropogenic, sector-specific strategies” for cutting emissions lie under the purview of other UN bodies.
That’s where it gets further complicated. The UN bodies that currently regulate international transport emissions are the International Civil Aviation Organization (ICAO) and the International Maritime Organization (IMO). Last year, ICAO adopted “long-term aspiration goals” to reach net zero emissions by 2050. And this week, the IMO is meeting at a conference in London to consider similar targets.
But asking officials to calculate and present those emissions for a global stocktake leads to a game of passing the parcel. The COP28 spokesperson said it welcomes “submissions by the IMO and ICAO on emissions, if they choose to do so.” In response to questions about whether the bodies would consider making such submissions, spokespeople for both said that it’s the decision of member countries on how to include emissions data in the COP28 process.
The technicalities of carbon accounting for international transport emissions are certainly challenging, but that’s not the reason why they haven’t been sorted out. The problem is that a few countries keep pushing a resolution off the agenda, said Armstrong. “The item got cut off the agenda every time because there was no political momentum to do it, and because a lot of countries wanted to block it,” he said, among them big oil exporters such as Saudi Arabia or Russia.
Unfortunately, physics doesn’t care much about politics. Whether the emissions are released within a country’s border or not, they all end up in the atmosphere, thickening the blanket that’s warming the planet.