We can't say for certain that any one event is caused by global warming. It's a global effect. The only thing we really need to point to is global average temperature, which should be plenty sufficient to cause alarm in everyone. Storms, fire, air quality, sea level rise, all of these things and more follow temperature rise. All of it together. Not any single event. We know that whole towns burned before the industrial age for all sorts of reasons. This alone does not prove or disprove a global effect.