Yes, your statement that no one can predict what the world will be like in 200 years is true.  No reasonable person would argue that.  Did you expect someone to argue a truism?

I'm not sure what you mean by "we" in your question about assuming the problems we have now will persist for 200 years or reappear 200 years from now.  I certainly don't assume that, and I don't think you do, either.  Are you saying that because we can't predict the future we shouldn't act as stewards of the environment?

I tried to respond to the last paragraph of your original post, which restates an argument I first ran across as an undergraduate in the 1970's.  I think now, as I thought then, that it's an interesting argument.   However, as I indicated, I think Luke has taken it into account and that his argument for good business opportunities is a strong one.  What do you think?