Commander Chris Hadfield, the astronaut currently living aboard the International Space Station, has tweeted that he will be photographing people's efforts during Earth Hour later today.
Good Morning, Earth! I'll try and photograph people's efforts during Eartrh Hour today. It's our planet, let's each help a bit.
More top news
Charlie Gard's parents are embroiled in a fresh High Court battle over whether the terminally ill baby can spend his final days at home.
The rogue surgeon was previously convicted of deliberately wounding his patients and carrying out needless operations.
A fine and warm day, but turning wet and windy tomorrow