# Creative Commons Attribution 4.0 International (CC-BY-4.0)

**Petrel Fuel Layer v1.0 — Global FM40 Crosswalk** — © 2026 Petrel Data.

This Layer is licensed under the **Creative Commons Attribution 4.0
International License (CC-BY-4.0)**.

Full legal code: https://creativecommons.org/licenses/by/4.0/legalcode
Human-readable summary: https://creativecommons.org/licenses/by/4.0/

## You are free to

- **Share** — copy and redistribute the material in any medium or format.
- **Adapt** — remix, transform, and build upon the material.
- **For any purpose, including commercially.**

The licensor cannot revoke these freedoms as long as you follow the license
terms.

## Under the following terms

- **Attribution** — You must give appropriate credit, provide a link to the
  license, and indicate if changes were made. You may do so in any reasonable
  manner, but not in any way that suggests the licensor endorses you or your
  use.
- **No additional restrictions** — You may not apply legal terms or
  technological measures that legally restrict others from doing anything the
  license permits.

No warranties are given. The license may not give you all of the permissions
necessary for your intended use — for example, other rights such as publicity,
privacy, or moral rights may limit how you use the material.

## Required attribution

When you use or redistribute this Layer (or a derivative), credit **Petrel** and
the two upstream sources it derives from. A reasonable attribution for most
media:

```
Petrel Fuel Layer v1.0 (Global FM40 Crosswalk), CC-BY-4.0.
Derived from © ESA WorldCover 2021 and Beck et al. (2018) Köppen-Geiger.
```

- **© ESA WorldCover 2021** — land cover (CC-BY-4.0),
  https://doi.org/10.5281/zenodo.7254221
- **Beck et al. (2018) Köppen-Geiger** — climate classification (CC-BY-4.0),
  https://doi.org/10.1038/sdata.2018.214

Indicate if you have modified the Layer (e.g. reclassified, resampled, or
clipped it).

## Why this Layer is CC-BY-4.0

v1.0 is CC-BY-4.0 — freely and **commercially** redistributable — because it is
built **only** from CC-BY-4.0 sources (ESA WorldCover 2021 × Beck Köppen-Geiger)
through a deterministic crosswalk. It uses **no** Meta canopy (CC-BY-NC), **no**
LANDFIRE, and **no** share-alike (ODbL) data. This is the defining property of
the crosswalk line, and the reason it replaces the earlier CC-BY-NC ML fuel line
(`fuel_v0.1/v0.2_global_ml`) as the free, commercial-clean fuel layer.

No separate commercial license is required to use the data. (Higher-volume
*API* download tiers are a service offering, separate from these data-reuse
rights — see `API_USAGE.md`.)

## Disclaimer

This dataset is provided "as is", without warranty of any kind, express or
implied. See `model_card.md` and `validation_report.md` for intended use,
validation status, and known limitations before relying on it.