If you were puzzled as to why Buckingham Palace, the Houses of Parliament, the Royal Albert Hall and the BFI IMAX were all in the dark this Saturday night, wonder no longer. It wasn't down to a very selective power-cut, but a voluntary switch-off in aid of WWF's Earth Hour. The hour (which takes place at 8.30pm worldwide) sees people all over the world switching off their lights to raise awareness about energy use and climate change.
It was set to be a big year, with 8 new joiners bumping the participating country count up to 152. Taking a look at the Twitter activity around the day, it's interesting to see that the tweet peak of 2048 didn't hit on the actual day of Earth Hour at all. The big push actually centered around anticipation for the next day's events as opposed to the event itself, which suggests more people may have been in support of the event than actually intended to participate.

As Earth Hour is held at 8.30pm in each country, we're able to attribute tweet spikes to time zones to give us an idea about which geographic regions were the most engaged. The highest spike of 710 tweets hit from the timezone incorporating China, Singapore and the Philippines, followed by another one of 510 we can attribute to Indonesia and Vietnam (amongst others). Interestingly founder country Australia, along with Canada (crowned Earth Hour "Capital" this year) delivered low volumes despite usually commanding high levels of participation.

Maybe this is suggestive of the way users chose to participate. There is an argument to be made that using your mobile during Earth Hour is counter-intuitive to the overall goal (which also explains the high push the day before) - so low online activity may in this instance be a positive indicator.
Celebs and split campaigns
The UK is one of the Earth Hour hubs that doesn't have a dedicated Twitter account (unlike Earth Hour Indonesia, which boasts over 30,000 followers). Most of the UK activity is driven via Facebook where they've amassed an impressive 83,140 likes. Getting involved were pop favourites McFly who helped live this year's campaign slogan, "Do it in the Dark" by performing a live gig in the dark as well as creating some hype with their own Panda Harlem Shake mashup, which hit only 209,000 views.
It's interesting that WWF included this hashtag on their Facebook header without any clear push to the Twitter page, which was also promoting the live gig with the hashtag #earthhourlive. From the 23rd to the 25th #doitinthedark pulled in just under 8,000 tweets with #earthhourlive just under 3,000 - not bad considering the WWF account consists of 21,532 followers to push from, and especially impressive when compared to the 2184 likes from the live stream announcement on their Facebook page.
It might be that the social power of your celebrity advocate can go a long way to spreading the word for a cause. McFly don't command anywhere near the Twitter followings of chart faves One Direction who cause a Twitter storm across everything from pancakes to performances - and recently lent a hand in this year's Comic Relief. Across the pond Diet Coke have snapped up Taylor Swift for their new advert; whether or not her 25 million followers was a factor is up for debate, but it would seem that the klout of your ambassador is becoming a consideration for smart marketers.
How effective is it all?
Celeb backing or no, the effectiveness of Earth Hour is difficult to measure.
Charting searches around the event and terms it wants to raise interest about, it's worrying to see not only that searches in Earth Hour are waning over time (although this year's data is not yet available), but that there's no distinct correlation in terms around saving energy and the event. However the one term there is a lift around is "climate change", indicating that there is an increase in awareness. Whether or not that goes on to change behavior is unclear.
