Don't confuse "the valley" with the rest of the planet. Where I live the only haze is from the wildfires in Kali due to poor forest and undergrowth management.Take a look at the soup bowl of air along the Wasatch front every winter, and then realize SLC is relatively small in terms of city sizes. Then tell me humans don’t impact the environment. People who want to pretend humans and carbon emissions aren’t impacting the planet have never once took a moment to look at studies on the issue, just like you couldn’t look at a short study on the exact conversation we’re having here above. Yes the climate can always be changing. That doesn’t negate the fact that we are having an impact.