tim, sorry, should have been more clear. we were in the habit of corresponding at least a few times a year up until that exchange. no, i have not written back since, as the tone of his email seemed clear to me ("not interested in discussing this issue further"). several months to a year would not have been unusual to pass, but 3 years is. in the past he has been more than interested & willing to discuss his geology projects and views with me. this just came across to me in two ways: "oh no, my buddy has been caught up in this crackpot idea of peak oil" and/or "this is something i don't want to be caught dead expressing an opinion on"