Dear all,

please allow me to quickly introduce myself: I'm Christoph Müller 
<https://www.pik-potsdam.de/members/cmueller>, 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 <https://agmip.org/> (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