It may not be very representative, but I've searched the websites of two leading local newspapers and found no mention of Earth Day in their issues today.
And on the official Earth Day website, the only event you can find organised in Hong Kong is an Earth Day Week organgised by a local company to promote awareness in reducing the office's carbon footprint.
That's as far as our awareness of and interest in the Earth Day get.
In contrast, Google uses this beautiful logo in its search page today:
In contrast, people and organisations all over the world are responding by taking actions or organising events. The actions that people post up to the official Earth Day website range from the more convention ones, such as
"I am trying to make others aware of the green movement by setting an example by recycling, becoming a vegetarian and saving water."
... to the more cheeky ones, like
"I had sex in the shower with my girlfriend and we used cold water and instead of having 2 showers we had 1 ;D with lights off... eu natural."
And there are a wide range of events, many of which show much creativity, like this "Adopt a Meter2 of Land" one...
Or this "All Green Everything" one...
For more details, go to the Earth Day official website and check them out.