I've just passed the three million credit mark and would like to encourage Facebook friends to participate. Since citing credit would mean nothing to them, I wonder if there is a way to roughly translate credit into number of model years run, something that would give people an idea of what the credit amounts to in work done. Any suggestions?

If you look at your account page, you'll see an item labelled "HadSM3 Model-Years", which does exactly what you want. The HADSM3 model was a relatively simple model run some years ago (also known as a "slab" model).

In your case your total is currently "HadSM3 Model-Years=19,989.83".

thank you sir!