There was a reason we killed of most of the bears in our past, not only were they a threat but also in competition. Now very few predators hold a position that man cannot easily fill. They talk about the balance in nature but many times in the past we see nature get way out of balance. Man does a better job of keeping nature in balance that nature does, eliminating the need for large predators.
That seems like an awesome trap statement to use when debating an Environazi. They will almost certainly disagree, and thus the perfect retort is note that we should then close the EPA and all other attempts at balancing nature, since we cannot do it. :)