As major U.N. climate talks open, pleas for action to back up big promises

“Two degrees more, and we jeopardize the food supply for hundreds of millions of people, crops wither, locusts swarm,” he said. “Three degrees, and you can add more wildfires and cyclones, twice as many. Five times as many droughts, and 36 times as many heat waves.” He continued, “Four degrees and we say goodbye to whole cities, Miami, Alexandria, Shanghai, all lost beneath the waves.”