Earth Day at 50: Pandemic Highlights Challenges Amid Progress (1)

The 50th anniversary of Earth Day arrives in the midst of a pandemic that has killed tens of thousands. The global shutdown also has cleared the skies in major cities, cast new light on the dangers of endemic air pollution, and muted one of the biggest events on the calendar for environmental activists.

At its half-century mark Wednesday, Earth Day is being webcast only.

The absence of mass gatherings will drain some of the day’s messaging power, said John Oppermann, executive director of the Earth Day Initiative. But he and others also said the virtual format could expand ...