Dear all,

please allow me to quickly introduce myself: I'm Christoph Müller, working at the Potsdam Institute for Climate Impact Research in Potsdam, Germany. I'm modeling crop growth and yield at the global scale for about 2 decades and also co-coordinate the Global Gridded Crop Model Intercomparison (GGCMI) in AgMIP (Agricultural Model Intercomparison and Improvement Project).

I'm reaching out to you, as the global-scale modeling has helped me to better understand the breadth of uncertainties from models (equations and parameters and user choices) leading to the hypothesis that crop models cannot be sufficiently evaluated by comparing to historical yield variation. Instead, we need more testing on functionality, common senses etc.

In order to make this a useful exercise to all, model developers and model users and science in general, I do ask all of you to take a little bit of your time to contribute ideas on what kind of test models should be exposed to (thanks!):

https://online.forms.app/cmueller/agmip-crop-model-test-survey

You input is very valuable, also if you're not a crop modeler yourself.
You can of course also directly reach out to me, but I hope that the survey will help organizing feedback.

Don't hesitate to ask if you have any questions.
Your input is greatly appreciated.

Cheers!
Christoph