![A combination picture shows the Galileo Galilei planetarium during Earth Hour (top) and after Earth Hour in Buenos Aires March 29, 2014. Lights go off around the world at 8.30pm local time A combination picture shows the Galileo Galilei planetarium during Earth Hour (top) and after Earth Hour in Buenos Aires March 29, 2014. Lights go off around the world at 8.30pm local time](https://c8.alamy.com/comp/2CYFK9D/a-combination-picture-shows-the-galileo-galilei-planetarium-during-earth-hour-top-and-after-earth-hour-in-buenos-aires-march-29-2014-lights-go-off-around-the-world-at-830pm-local-time-in-a-show-of-support-for-renewable-energy-during-earth-hour-an-event-organised-since-2007-to-promote-a-sustainable-future-for-the-planet-reutersmarcos-brindicci-argentina-tags-environment-energy-travel-society-2CYFK9D.jpg)
A combination picture shows the Galileo Galilei planetarium during Earth Hour (top) and after Earth Hour in Buenos Aires March 29, 2014. Lights go off around the world at 8.30pm local time
![Buenos Aires, Argentina. 16th June, 2019. A citizen lights candles during a blackout in Buenos Aires, Argentina, June 16, 2019. The massive blackout occured in Argentina at about 7:00 am local time ( Buenos Aires, Argentina. 16th June, 2019. A citizen lights candles during a blackout in Buenos Aires, Argentina, June 16, 2019. The massive blackout occured in Argentina at about 7:00 am local time (](https://c8.alamy.com/comp/TDKJ88/buenos-aires-argentina-16th-june-2019-a-citizen-lights-candles-during-a-blackout-in-buenos-aires-argentina-june-16-2019-the-massive-blackout-occured-in-argentina-at-about-700-am-local-time-1000-gmt-and-also-hit-uruguay-southern-brazil-and-multiple-cities-in-chile-credit-martin-zabalaxinhuaalamy-live-news-TDKJ88.jpg)
Buenos Aires, Argentina. 16th June, 2019. A citizen lights candles during a blackout in Buenos Aires, Argentina, June 16, 2019. The massive blackout occured in Argentina at about 7:00 am local time (
![A combination photo shows the Buenos Aires' Obelisk before (L) and during Earth Hour March 27, 2010. Earth Hour, when everyone around the world is asked to turn off lights for an A combination photo shows the Buenos Aires' Obelisk before (L) and during Earth Hour March 27, 2010. Earth Hour, when everyone around the world is asked to turn off lights for an](https://c8.alamy.com/comp/2E7691W/a-combination-photo-shows-the-buenos-aires-obelisk-before-l-and-during-earth-hour-march-27-2010-earth-hour-when-everyone-around-the-world-is-asked-to-turn-off-lights-for-an-hour-from-830-pm-local-time-is-meant-as-a-show-of-support-for-tougher-action-to-confront-climate-change-the-symbolic-one-hour-switch-off-first-held-in-sydney-in-2007-has-become-an-annual-global-event-and-organizers-world-wide-fund-for-nature-wwf-said-they-expect-this-years-to-be-reutersenrique-marcarian-argentina-tags-environment-cityscape-2E7691W.jpg)