So tomorrow night, in a reprise of the ‘60s counter culture movement, spend an hour (or longer) by candlelight

It's on again. Tomorrow night, Saturday 29 March at 8.30pm is Earth Hour 2014.

Earth Hour is the key event for World Wide Fund for Nature (WWF). It's a reminder about climate change and how the world's humans, animals and environment will be impacted by changes in the temperature and biodiversity. In the event's seven-year history it's been embraced by over 7,000 cities in 152 nations across the world. And it started right here in Australia.

This year organisers are bringing it back to basics and reminding everyone exactly why we need to take action on climate change. It's being linked to one of the world's most iconic and threatened places: Australia's Great Barrier Reef. This natural marvel in our own back yard is comprised of 2,900 individual reefs and 900 islands stretching over an area of approximately 344,400 square kilometres.

For more information about how the Reef will be affected by climate change, the Great Barrier Reef Marine Park Authority has some great videos explaining exactly what rising temperatures, rising sea levels and ocean acidification will do to the Reef. Add to that the impact from sea dredging and dumping, agricultural runoff and oil spills and you have the world's largest coral reef under threat from all directions.

And for the skeptics or pessimists out there, you may well ask whether shutting down the lights for one hour will make a difference. That's up to you. It's intended more as an awareness-raising gesture than a direct means of cutting greenhouse gas emissions.

One of the biggest impacts of Earth Hour I've seen was with a work colleague a few years ago who raved about his Earth Hour experience. With all the lights and the TV switched off, he and his wife, along with their two little girls, had a picnic on the floor playing Monopoly and Hungry, Hungry, Hippo until it was time for bed. Then to cap off it all off, the bedtime stories were read by candlelight. The family enjoyed it all so much they decided to have a weekly blackout, and they were buying more board games and culling TV use.

So tomorrow night, in a reprise of the ‘60s counter culture movement of "turn on, tune in, drop out"... turn off your lights, tune out your phone and drop in on a friend. Have an actual conversation. Light some candles to help save our Great Barrier Reef. Or future generations might be lighting them in memory of it.