After the embargo period (see the Workflow for contributions to ISIMIP), model output data is published in the ISIMIP repository, where it is immediately made publicly available according to the restrictions of the license assigned to them.
Licenses on datasets are a non-trivial topic, you can check some readings on the topic here, here and here (in German). You should also keep in mind that model licenses are different to model output licenses.
As of ISIMIP3, we encourage the use of the CC0 - Public Domain Dedication for all model output. Under CC0, all copyright interests and database rights are waived, so we consider this perfectly suitable to use with ISIMIP data. Working under the CC0 waiver allows anyone to use the data for derivative work in any way and for any purpose, including commercial purposes. Regardless of the legal implications, we request to follow our terms of service, including the correct form of attribution of the datasets. For more information, see the CC0 FAQs.
For ISIMIP2 (and Fast Track), ISIMIP's preferred license for output data was the CC BY 4.0, but some modelling groups selected other Creative Commons (CC) licenses. You can find every available model output license information in the tables below (ISIMIP2b, ISIMIP2a, FastTrack) and in our ISIMIP model data base (most up to date). The modelling groups with individual model restrictions in Fast Track are listed here.
There are nuances to license inheritance, depending on whether parts of the source data used appear identically in your simulation data. Before assigning a license to a data set of your own creation, please check the licenses of all data sets you used in its creation, as some licenses are inherited (e.g., CC BY-SA 4.0). In addition, given that ISIMIP data might be derived from other data sets, those rights also have to be considered.
Please clarify the legal consequences of licensing with your own institutions before assigning any license to your simulation data, as the database producer right is often not with the researchers. If you are associated to PIK, this issues are covered in the Open Science Policy of the Institute (https://www.pik-potsdam.de/en/output/software-data-models/open-source/PIKOpenSourceOpenDataPolicyMay2019.pdf).
IMPORTANT: Creative Commons (CC) licenses cannot be revoked. Please choose your license carefully.