Canada issues air quality warnings over US wildfire smoke after Trump tariff threat By Olivia Bowden in Toronto Officials say smoke from US fires has crossed border days after US president accused Canada of improper fire management https://www.theguardian.com/world/2026/jul/20/canada-air-quality-warnings-us-wildfire-smoke-trump-tariffs #Wildfires #Worldnews #USnews #Canada #Trumpadministration #Americas #TheGuardian #OliviaBowdeninToronto