What is considered Greener/Greenest laminate flooring option available?
In my last kitchen remodel, I used linoleum, mostly because it was a natural and "green" product. Note that vinyl flooring is often inappropriately called linoleum. You can read more online, but I thought it looked great, was easy to install and care for, and supposedly lasts a very long time.

Here is a Georgia Tech labelled paper that discusses the different choices, rating them on environmental impact and other factors.


  Linoleum is made from all natural ingredients. Linseed oil is derived by pressing flaxseed and it is dried and ground into a powdery binder. This is combined with limestone, which is extremely abundant, pine rosin, and cork and wood flours to form a doughy material to which color is added. Once pressed, it is rolled onto a jute backing and dried. Jute is
  spun from fibers of jute plants grown in India and Bangladesh (Forbo Industries).


Resilient Flooring: A Comparison of Vinyl, Linoleum and Cork

Edit: I just reread your question more carefully, and see that you're specifically looking for click-lock products. Forbo makes a product like that, Marmoleum click tiles which is their brand of linoleum "Marmoleum" applied on top of an HDF and cork backer. Note that my comments about linoleum apply to the linoleum material and jute backing. I don't know what glues or other materials are used in that specific product. I used glued-down tiles.