The Marvel Universe has faced its fair share of apocalyptic events - giant monsters, alien invasions, and futuristic conquerors - but it still has to contend with those from the real-world. In both the real world and Marvel's, former Vice President Al Gore has long been on the forefront of trying to get the US to take global warming and its eventual impact on the planet much more seriously. So why in the world would Spider-Man punch him in the face?
The altercation happened in Dan Slott's "Ends of the Earth" Spider-Man story, which saw a dying Doctor Octopus and his assembled Sinister Six publicly announcing to the world that they could save the planet from the damaging effects of global warming, which Doc Ock had recently worsened in a demonstration of orbital technology he dubbed Octavian Lenses. Naturally, an international meeting of the world's leaders was called, and Spider-Man and the Avengers were in attendance as well. When Gore stood to speak, he shared that he was in favor of working with Doctor Octopus and accepted his offer to supposedly save the planet. Spider-Man wasted no time in decking Al Gore with a solid right hook to the face.
While this was naturally a massively shocking move on Spider-Man's part, the Webslinger had his reasons. Peter had long been expecting the Sinister Six to strike once more, so he'd been building a brand new suit to help him better combat the evil team. Using new sensors in his suit, Spider-Man was able to easily detect that Al Gore was not his true self at all, but the Chameleon in disguise, there to make sure things went in Octavius' favor.
Spider-Man was totally prepared for Doc Ock and the rest of the Six thanks to his new suit. It seems as though his foresight was pretty solid, seeing as how this attack was on a level Octavius had never truly attempted before. As the story continued, the Sinister Six gained enough upgrades to their powers that they were able to incapacitate the Avengers themselves, leaving Spider-Man to be one of the sole heroes left to go toe to toe with Octavius by the story's end.
Thankfully, it doesn't seem as though Spider-Man has any real beef with the former vice president. Giving a fictional character some sort of animosity with a real public figure who's involved in such a political hot topic would certainly have been a controversial move on writer Dan Slott's part. Furthermore, it seems as though Spider-Man does care about the planet, as his hunch that Doc Ock was up to more than goodwill was the right call. He learned that Doc Ock had been planning from the very beginning to annihilate the majority of the entire world's population, leaving only a small percentage living to remember his dark legacy. By socking the apparent Al Gore, Spider-Man was able to stop Ock's plans and prevent the planet from burning up prematurely, leaving the world with a little more time to figure out the global warming crisis for themselves.