The metric might not mean much to laypeople, but leap seconds have been a source of contention in the timekeeping community for years. Now, they’re dead.

Seven of 16 planetary vital signs are in their most extreme state ever recorded, and El Niño is here to make matters even worse.

The US is home to some of the most polluted air on the planet as smoke from 120 out-of-control Canadian wildfires drifts across the border.