FAP, June 13 (Xinhua)-- smog that has lasted for several weeks continues to cover western Canada, and hundreds of wildfires continue to ravage Canada, destroying more than 47000 square kilometers of land. This week, smog crossed the Atlantic and reached the skies over Europe. Some scholars have pointed out that the relationship between human beings and fire may have changed, and climate change is causing wildfires to become more violent and frequent.