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.