When a rotten egg smell rises from the mangrove swamps of southeast Mexico, something is going well. It means that this key coastal habitat for blunting hurricane impacts has recovered and is capturing carbon dioxide — the main ingredient of global warming. While world leaders seek ways to stop the climate crisis at a United Nations conference in Scotland this month, one front in the battle to save the planet’s mangroves is thousands of kilometers away on Mexico’s Yucatan Peninsula. Decades ago, mangroves lined these shores, but today there are …

The astronauts who will depart the International Space Station on Sunday will be stuck using diapers on the way home because of their capsule’s broken toilet. NASA astronaut Megan McArthur described the situation Friday as “suboptimal” but manageable. She and her three crewmates will spend 20 hours in their SpaceX capsule, from the time the hatches are closed until Monday morning’s planned splashdown. “Spaceflight is full of lots of little challenges,” she said during a news conference from orbit. “This is just one more that we’ll encounter and take care …