At worst we wouldn't do anything for 1,000 years because there's been little effect. In the meantime we've built up another 1,000 years we're going to have to

At worst we wouldn't do anything for 1,000 years because there's been little effect. In the meantime we've built up another 1,000 years we're going to have to deal with, which might be impossible at that point. In comparison, if we instantly felt the effects we could obviously see we're causing specific problems, and react appropriately. With the lag it's a crapshoot and deniability can creep in.