A few months ago, Mary Wagner woke up to the smell of smoke from wildfires in California and northern Nevada. She readied her sons for school and stepped outside into the smoky Las Vegas air. Her 13-year-old son’s asthmatic cough worsened. “It’s really, really bad and it’s really hard for him to breathe,” she recalled. This summer, the city also sizzled under prolonged, record-breaking temperatures of 46.11 C or greater. Wagner knows days will get hotter and wildfires more frequent with climate change. That’s why global warming is a critical issue for her in this election. “Seeing how climate …