World Wildlife Fund of Nature -WWF, an international non-governmental organization that deals with issues of conservation, research and environmental restoration reports that the earth is in crisis. The damage to the earth has gone so fast. Based on the report of the WWF-UK -Living Planet Report, 80 percent of the water species are destroyed, while more than 50 percent of the land animal population has went extinct. 40 per cent of forests have been transformed into agricultural land and 15 million trees as raw materials get lost each year. In addition, climate change makes one of the six species in the world under threat of extinction. To save the earth, WWF does an activity called ‘Earth Hour’. Actually, what is Earth Hour and what is the purpose of the activity? Earth Hour, which means in Indonesian language ‘Jam Bumi’, is a global event organized by the WWF at last Saturday of March each year. This activity is in the form of blackouts in homes and offices for one hour to raise awareness of the need for serious action against climate change. The WWF initiative was first held in 2007. At that time, 2.2 million Sydney residents participated in by extinguishing all unnecessary lights. After Sydney, several cities around the world participated in the Earth Hour 2008. This year, Earth Hour is held in 180 countries, including in Indonesia. As in previous years, several cities in Indonesia participated in the Earth Hour activities. On Saturday night (24/3/2018) from 20:30 to 21:30 local time, the commemoration of the Earth Hour Indonesia 2018 is held simultaneously in Indonesia. This year, there are 60 cities to participate in the Earth Hour Indonesia 2018, including Jakarta, Banjarmasin in South Kalimantan, Yogyakarta and Pontianak in West Kalimantan. Quoted from the official website of the WWF, turning off the lights for 60 minutes becomes a symbol that shows solidarity for the earth planet. Although it is only done for 1 hour and once every year, the Earth Hour activity is proven to have a very huge impact, especially in saving energy. For the area of ​​Jakarta, blackouts are conducted at Bung Karno Main Stadium, Town Hall Building, National Monument -Monas, Welcoming Monument, and Simpang Susun Semanggi. As a result, Jakarta provincial government is estimated to save 170 megawatts of electricity. In addition to saving in terms of cost and power, power outages by the city government also have a major impact on the reduction of greenhouse gas emissions. What about in the world? In addition to saving energy, for about 10 years of action, the Earth Hour has helped create 3.4 million hectares of Argentina's marine protected area, 2,700-hectare forest in Uganda and new laws for marine and forest protection in Russia. Seeing the great benefits of the Earth Hour, in the future, not only government offices and buildings, but also other places belonging to individuals or private companies will participate in this Earth Hour activity. Energy savings should be done not only once a year for an hour, but also every single day for an hour continuously. The Earth Hour is just one of the few efforts that can be done to save the earth. Let's do something, so the Earth becomes a comfortable place to live on.