The Earth Hour Expo was held by charity Greenrock yesterday.Residents turned out at City Hall for the event and switched off their lights for an hour, for the fourth year running.Earth Hour has been celebrated by millions of people in more than 130 countries, since 2007.The idea is to raise awareness about the importance of a sustainable lifestyle with the aid of green exhibitors and entertainment.Said Greenrock member Eugene Dean: “This year's Earth Hour Expo [sought] to showcase simple solutions to climate change, now a global crisis, while providing more avenues for raising awareness about its harmful effects. Living more sustainable lifestyles is something that each of us can achieve, hence our commitment to supporting initiatives of this nature as we seek to change mindsets in our Island home.” i