Accurate radiative transfer calculation is fundamental to all climate modelling. For deep palaeoclimate, and increasingly terrestrial exoplanet climate science, this brings both the joy and the challenge of exotic atmospheric compositions. The challenge here is that most standard radiation codes for climate modelling have been developed for modern atmospheric conditions, and may perform poorly away from these. The palaeoclimate or exoclimate modeller must either rely on these or use bespoke radiation codes, and in both cases rely on either blind faith or ad hoc testing of the code.

The  Palaeoclimate and Terrestrial Exoplanet Radiative Transfer Model Intercomparison Project (PALAEOTRIP) aims to systematically address this. We will compare as many radiation codes used for palaeoclimate or exoplanets as possible, with the aim to constrain the ranges of far-from-modern atmospheric compositions in which the codes perform well.  

The complete rational and protocol for the intercomparison is now published and available as:
C. Goldblatt, L. Kavanagh, and M. Dewey, The Palaeoclimate and Terrestrial Exoplanet Radiative Transfer Model Intercomparison Project (PALAEOTRIP): experimental design and protocols, Geosci. Model Dev., 10, 3931–3940, 2017,

If you're interested in contributing to this project, please read through our protocol and when you're ready submit your data on this site.