The structure of global climate models

Strusture of the NASA GISS global climate model

Strusture of the NASA GISS global climate model

Don’t believe in global climate modelling? Maybe you should actually read something about it before cementing a conclusion. A new paper¹ by Kaitlin Alexander (now at UNSW) and Steve Easterbrook (Toronto) is moderately approachable and gives some interesting insights:

  • Did you know that US global climate models are structurally quite different from European models?
  • Or that the Hadley Centre’s global climate model (HadGEM2) uses the atmospheric module from the UK Met Office’s operational weather model, essentially unchanged?
  • It’s common for modelers to share code. Even though “pinched” code modules may be greatly altered and developed over time, they probably explain some aspects of consensus between different models. Those building multi-model ensembles in an effort to improve overall skill and elicit uncertainty need to carefully consider the effects of code sharing.

Why not actually know something about the subject, rather than just believing it? It’s not all that hard.



  1. Alexander, K., and S. M. Easterbrook. “The software architecture of climate models: a graphical comparison of CMIP5 and EMICAR5 configurations.” Geoscientific Model Development Discussions 8.1 (2015): 351-379.

    (It’s good to see professors publishing with their student’s name first. Everyone needs a start, and as a teacher it’s your job to see they get one.)