As far as I know, what you seek is the Texture Hack. THis will remove all the grass and so from the ground and the trees etc.
And if you think of a mod that do this....
Well, you can't remove the grass and so, unless it's a model. (Mostly like not) Or a FX...
This you may find in each map ff file. Located in your Mw2 Folder.
Use FF.Viewer to view the files.
So your question asnwer is:
You seek the texture hack, and yes. It will ONLY affect you, no other players.