Earth Hour is an international movement, coordinated by WWF, to put a spotlight on the problems arising around the climate change. A simple but concrete gesture, to switch off the lights for one hour on the same day, proofs that together we can make the difference. Starting as the first lights out event in Sydney in 2007 the movement spread around the world leaving squares, streets and monuments in the dark. For a common goal: to stand up against the climate changes. But what are the climate changes? They are a consequence of the global warming. At the end of 19th century, Svante Arrhenius, Swedish scientist and Nobel price winner, was the first to show the theory of the greenhouse effect, saying that CO2 concentration in atmosphere has an influence on the temperature on the Earths surface. Since then the awareness that mankind has an influence on the climate has constantly grown. Climate changes are proceeding rapidly and the consequences are increasingly serious and alarming, especially regarding animal- and flora species. The COP21 Paris agreement from 2015, is a landmark agreement to combat climate change, that may lead to a reversal of the trend, unless we succeed in accelerating the decarbonisation, and intensifying the use of renewable energy as well as adopting efficient and energy saving options. For this sake we have to join in a common effort, and contribute ourselves by demanding concrete actions from our governments. The future generations have the right to inherit a world full of healthy biodiversity. Let’s save the world! It’s the only planet with Chocolate!