Tonight at 8:30 pm, more than one hundred countries on every continent will be taking part in Earth Hour, which was founded by the World Wide Fund for Nature (WWF) in 2007 as a symbolic way of raising awareness about climate change and the world’s depleting resources.

Big monuments around the world like Big Ben in London, Sydney’s Opera House, Great Wall of China, the Brandenburg Gate in Berlin and the Vatican Dome already announced that theywill be part of the movement. In Costa Rica, companies like the Costa Rican Institute of Electricity (ICE) is sending text messages to invite the people joining the action.

This year, the Earth Hour matches with the International Year of Sustainable Energy, initiated by the UN in order to raise awareness about the importance of increasing access to a efficient, sustainable and renewable energy.

So, will you be part of it?