There will probably be only cities. So they would have to live on rooftops to get sun rather than on the ground. But they wouldn't be able to get to hot so they could sunbathe for hours. There are many ideas for defense but here are a few of ideas for it. Chameleons already have spikes on their back for protection. So in the future they will probably have bigger spikes used to scare their predators. Also their skin flap under their chin would be longer to scare off predators. And it will be 10 times bigger than it is now. Trough its sweat glands it can soak up gas, water or light. When this happens the sweat glands filters them from all the pollution, this will give them energy. Also they will have teeth that are super strong so they will be able to eat pipes and metal. Their stomach has very powerful cell tissue and stomach acid that can digest the food. They will also be able to eat birds, dogs, cats and other animals its size. They will have long arms for grabbing to roofs and the sides of them. Also the would have a tail that they would hang from pipes to ambush prey from the top. They will also live on the top of the roofs and would hang on the sides of them. There eyes would be the same as they are now. It will be able to survive in its habitat because it will be able to become invisible. It can camouflage now so it will put more of its energy to evolve to be able to become invisible. And when its not invisible it will be black due to the smoke. And they would be.
Thank you for your interest in contacting Future Engineers. We look forward to connecting with you!