Tonight is the 11th annual Earth Hour!

This Saturday evening between 8:30 and 9:30 is the 11th annual Earth Hour. For 60 minutes, everyone is encouraged to turn off all non-essential lights. This means everything except for things like traffic lights or aircraft warning beacons on radio towers. For everyone else, it's time to break out the candles! It is done to show awareness and support for the planet and issues such as climate change and carbon emissions.

Quickly became popular

Last year's Earth Hour in Moscow, Russia. (Getty Embed)

Earth Hour was started only 10 years ago as a lights-out event in Sydney, Australia, and since then, it has grown to become a global event. Cities in nearly every country in the world observe Earth Hour. (If you're keeping track, six continents, over 170 countries, and all 24 time zones will be celebrating.) This means that you're going to notice a lot of dark homes and office buildings tonight!

It also means that the event has come to be about a lot more than just turning out the lights. TVs, computers, stereos... people are switching them all off to save energy and get into the spirit.

What's more, many public spaces are planning on have gatherings, and that includes having entertainment such as acoustic music (which is played without using any electricity, naturally!). Most cities and towns across North America are likely to be having some kind of event, so if you're interested, see what's happening and maybe make plans with family or friends to head out!

Act hourly, think yearly

Toronto's skyline during Earth Hour 2012. (Getty Embed)

Of course, there's also nothing wrong with just staying in and playing some board games or reading by candlelight. In the end, Earth Hour is not so much about how much energy can be saved in one hour (though that amount is still quite something). Organizers hope that this one hour of action can remind and influence people about how they act all year. After all, how often do we leave lights on when we don't need to? Are their appliances around your home that are left plugged in when they don't need to be? Could you even try having "Earth Evenings" every week—one night where you leave the lights off and save some power?

The possibilities are endless. Let us know what you're planning for Earth Hour and have a lovely, low-energy night!