Earth Hour.

Today in many countries all over the world the Earth Hour is celebrated. This means that the lights of monuments and famous places would be turned off for a hour to save energy and to fight climate change.

Here an insiping video about Earth Hour:

I think that it's really good idea.
I'd like to go beyond the turning off the lights. I think that the most dangerous form of pollution at the moment is electromagnetic pollution.
It would be nice to have a no-emf pollution hour too. It would not be very difficult and everyone could be part of it.
Just turn off your cell phone(s) and your wi-fi stuff. And keep them off as long as you can.
The whole planet would benefit from this.