Modern life makes us tired, right? But research from societies in Africa and South America suggests people in the ancient world slept only 6.5 hours a night.

During the first week of his second term, President Trump issued a slew of executive orders (EOs) and presidential memorandums that directly ...

Global mean surface warming throughout the 21st century will be largely determined by cumulative emissions of carbon dioxide (CO 2) and the other long-lived greenhouse gases, and what proportion of ...