The U.N. General Assembly adopted a “Pact for the Future” to meet the challenges of the 21st century. Now comes the hard part: uniting the world’s divided nations to move quickly to implement its 56 actions.

On air quality maps, purple signifies the worst of it. In reality, it's a thick, hazardous haze that’s disrupting daily life for millions of people across the U.S. and Canada, blotting out skylines and turning skies orange.