I don't think we are the most intelligent. I doubt the world would have so much pollution and so little ozone had humans never shown up. Would the sharks and whales have used fossil fuels and nuclear energy to destroy our ozone? Would the Buffalo and lions have made cars that emit toxic fumes into the breathing air? My guess is not. We claim that we are the most intelligent on the planet, yet we have dealt the most damage to it.
Honestly, I don't see humans lasting much longer. Maybe a few hundred more years until we start having fatal problems as a race.
But that's all my opinion, of course. I know we are taking steps to recover the damage we have done, I just don't think we will recover at the same rate at which we damage the planet. Stalling the inevitable, if you will. Not the brightest outlook, I know, but it's my outlook none the less. Sorry.