The disgraceful panic over rising CO2 levels has led to many harms, not least to the mental well-being of children, and the physical well-being of just about everyone. The jejune 'Earth Hour' is but one manifestation of the rot that has spread into many groups, organisations, and even governments.
Celebrate 'Human Achievement Hour' instead: https://cei.org/humanachievementhour
Or, how about 'Energy Hour': https://climatelessons.blogspot.co.uk/2012/03/earth-hour-is-phoney-energy-hour-is.html
And the 'must-read': https://climatelessons.blogspot.co.uk/2013/03/i-abhor-earth-hour-abundant-cheap.html
Note added 24 March. Jo Nova calls for 'Power Hour': http://joannenova.com.au/2018/03/fight-the-forces-of-darkness-celebrate-powerhour-tonight/
'It’s your chance to show your commitment to fighting the forces of darkness.'
Note added 25 March. Mark Morano's site provides more links to sensible responses to the 'Earth Hour' lunacy: http://www.climatedepot.com/2018/03/24/star-treks-william-shatner-promotes-earth-hour-darkness-but-he-is-rebuked-by-forces-of-light/