I was struck by how relaxed and happy everyone seemed. Sydney is a gorgeous city, with 100 beaches and a come-as-you-are attitude — famously on display in neighborhoods like Bondi Beach.

During the intermission, we stood out on the western plaza and took in the view of the Central Business District, or CBD, as locals call it — the heart of downtown Sydney, which includes popular ...

Sydney is not the first place to cut the lights for conservation. In February, Paris and other parts of France dimmed lights for five minutes in a gesture that also took hold in Rome and Athens.