![A combination photo shows the 'Welcome To Fabulous Las Vegas' neon sign before (top) and during Earth Hour in Las Vegas, Nevada, March 27, 2010. Countries around the world have signed up for Earth Hour on Saturday in which homes, office towers ... A combination photo shows the 'Welcome To Fabulous Las Vegas' neon sign before (top) and during Earth Hour in Las Vegas, Nevada, March 27, 2010. Countries around the world have signed up for Earth Hour on Saturday in which homes, office towers ...](https://l450v.alamy.com/450v/2e77587/a-combination-photo-shows-the-welcome-to-fabulous-las-vegas-neon-sign-before-top-and-during-earth-hour-in-las-vegas-nevada-march-27-2010-countries-around-the-world-have-signed-up-for-earth-hour-on-saturday-in-which-homes-office-towers-and-landmarks-will-turn-off-their-lights-from-830-pm-local-time-to-raise-awareness-about-climate-change-and-the-threat-from-rising-greenhouse-gas-emissions-reutersrichard-brian-united-states-tags-environment-cityscape-2e77587.jpg)
A combination photo shows the 'Welcome To Fabulous Las Vegas' neon sign before (top) and during Earth Hour in Las Vegas, Nevada, March 27, 2010. Countries around the world have signed up for Earth Hour on Saturday in which homes, office towers ...
![A combination photo shows the 'Welcome To Fabulous Las Vegas' neon sign before (top) and during Earth Hour in Las Vegas, Nevada, March 27, 2010. Countries around the world have signed up A combination photo shows the 'Welcome To Fabulous Las Vegas' neon sign before (top) and during Earth Hour in Las Vegas, Nevada, March 27, 2010. Countries around the world have signed up](https://c8.alamy.com/compfr/2e74yey/a-combination-photo-shows-the-welcome-to-fabulous-las-vegas-neon-sign-before-top-and-during-earth-hour-in-las-vegas-nevada-march-27-2010-countries-around-the-world-have-signed-up-for-earth-hour-on-saturday-in-which-homes-office-towers-and-landmarks-will-turn-off-their-lights-from-8-30-pm-local-time-to-raise-awareness-about-climate-change-and-the-threat-from-rising-greenhouse-gas-emissions-reuters-richard-brian-united-states-tags-environment-cityscape-2e74yey.jpg)
A combination photo shows the 'Welcome To Fabulous Las Vegas' neon sign before (top) and during Earth Hour in Las Vegas, Nevada, March 27, 2010. Countries around the world have signed up
![A view of the darkened 'Welcome To Fabulous Las Vegas' neon sign is seen during Earth Hour in Las Vegas, Nevada, March 27, 2010. Countries around the world have signed up for A view of the darkened 'Welcome To Fabulous Las Vegas' neon sign is seen during Earth Hour in Las Vegas, Nevada, March 27, 2010. Countries around the world have signed up for](https://c8.alamy.com/comp/2D2FD6M/a-view-of-the-darkened-welcome-to-fabulous-las-vegas-neon-sign-is-seen-during-earth-hour-in-las-vegas-nevada-march-27-2010-countries-around-the-world-have-signed-up-for-earth-hour-on-saturday-in-which-homes-office-towers-and-landmarks-will-turn-off-their-lights-from-830-pm-local-time-to-raise-awareness-about-climate-change-and-the-threat-from-rising-greenhouse-gas-emissions-reutersrichard-brian-united-states-tags-environment-cityscape-2D2FD6M.jpg)