On Saturday the 28th of March is Earth Hour. To take part in this global event, all you need to do is to switch off your lights at 8.30pm for an hour. Which is pretty easy! There is more about Wellington’s efforts for the day here.
(I initially said that it was this Saturday, which is wrong, although you could still turn your lights off for an hour if you wanted to.)
Read about Earth Hour here, or watch some of the Youtube clips below.