Global warming may be making income inequality worse across the world. This Earth Day, Stanford University researchers said gradual temperature increases over almost five decades have helped created financial disparities between poorer, typically warm countries and richer, typically cooler countries. Without climate change, the divide between nations with the largest economic output per person and nations with the smallest output per person would be 25% smaller, says the new study. Instead, climate change has been a drag on growth for many poorer countries and enriched many wealthy countries. “Countries that are very warm tended to exhibit slower economic growth whereas...