“The climate alarm is blaring from every direction,” said UN Climate Change Executive Secretary Simon Stiell in a statement. “With the mercury set to soar again this week, the awful costs of this climate crisis – both human and economic – are now reaching national emergency levels.” Indeed, smoke from wildfires can travel thousands of kilometres, crossing borders, oceans and continents. Understanding where it will go next has become an increasingly important scientific challenge, the World Meteorological Organization (WMO) has reported. WMO said that reliable monitoring, forecasting, cross-border data sharing and early warnings are critical to protect lives, livelihoods and ecosystems.