COVER STORY This issue: The Secrets of Happiness Experts. If anyone knows the secret to happiness, it’s surely the people who have dedicated their careers to studying it. The first thing they’ll tell you? Being happy all the time isn’t a feasible—or even desirable—goal.“It’s not a yellow smiley face,” says positive-psychology expert Stella Grizont, founder and CEO of Woopaah, which focuses on workplace well-being. “It’s being true to yourself and all the emotions that come up.” Grizont was among 18 leading happiness experts surveyed by TIME about their daily habits, and the professional insights they’re most likely to apply to their personal lives. The results are illuminating—and could help all of us boost our mood and well-being…To understand the world we live in, read TIME.

Beatrice Fihn isn’t giving up on a future free of nuclear weapons. March 2017 was an exhilarating time for Beatrice Fihn. The executive director of the International Campaign to Abolish Nuclear Weapons (ICAN) was at the U.N. in New York City for talks with more than 120 countries to negotiate a treaty on banning nuclear weapons. One moment still stands out: Nikki Haley, then U.S. ambassador to the U.N., and a group of diplomats from several NATO countries held a press conference outside the General Assembly to protest the talks…

A movement in Brazil is reimagining agriculture to save the industry and the rain forest. In a field of bare red dirt in São Paulo state, Paula Costa is trying to turn back the clock. Five hundred years ago, this land was part of the Mata Atlantica, a dense, diverse rain forest that covered 15% of Brazil. Its trees stretched more than 2,000 miles along the eastern Atlantic coast, and far inland. But today 93% of the forest has been stripped of trees, with much of it turned over to monoculture farming. Costa, a 36-year-old biologist, bangs the ground with her fist: it’s hard, the dry soil degraded by the tropical sun…