Release history
Which version produced a figure
Figures on this site move between releases, and not always because European flying changed. This page says what changed and why, so that a difference can be read for what it is.
Published
| release | covers | what changed | archive |
|---|---|---|---|
| 2026-09-01 | 2026-01-01 → 2026-07-20, 197 days 1,833,127 flights · methodology v1.0 |
First release. The gap against an ideal flight, computed for every flight that passes the quality gates in the ECAC area over the covered period, split into a lateral and a vertical component, with the phase attribution of the vertical part and a context page for the external figures. | 10.5281/zenodo.22215589 |
Planned — 2027-01-31
Covering the whole of 2026, twelve months.
Two things move at once, and neither is Europe flying worse. The window changes from the 197 days of this release to twelve months, so every headline figure shifts for reasons of perimeter. And the cruise baseline is under revision: measured on its own, the cruise segment currently comes out negative, meaning real aircraft burn less than what this model calls optimal — a baseline that is too generous. Correcting it makes the ideal flight cheaper and therefore the gap larger. Both changes push the headline in the same direction, and a reader who is not told will read the sum as a deterioration.
It is written here before the fact rather than explained after it, because a change announced in advance can be checked and one explained afterwards can only be believed.
From the January 2027 release onwards, releases are twice a year, at the end of January and the end of July, and each one carries twelve months rather than the calendar half it follows: a rolling window contains every season, and this site's own figures are seasonal. The cost, stated plainly: two consecutive releases share six months of data, so movements between them are damped.
Citing a version
How to cite. What is citable here is the tool, not a study: the figures are outputs of running it, and anyone can re-run it.
co2gap (2026). co2gap — an open pipeline for measuring the CO2
of European flights against a fuel-optimal ideal, from ADS-B trajectories. Release 2026-09-01,
methodology v1.0, covering 2026-01-01 to 2026-07-20.
https://co2gap.org
DOI: 10.5281/zenodo.22215589
That DOI identifies this release and never moves: it will still resolve to the 2026-09-01 figures after later releases exist. To cite the project across all versions, use 10.5281/zenodo.22215588, which always resolves to the most recent one. Three version strings name three different things: release 2026-09-01 is the window of data, methodology v1.0 is the method, and v1.0.0 is the software tag the archive was cut from.
BibTeX
@software{co2gap_2026,
author = {co2gap},
title = {co2gap: an open pipeline for measuring the CO2 of European
flights against a fuel-optimal ideal, from ADS-B trajectories},
version = {2026-09-01},
url = {https://co2gap.org},
doi = {10.5281/zenodo.22215589},
year = {2026}
}The machine-readable form is CITATION.cff in the repository.