Ice ages, warm periods, impacts by asteroids – the climate on our planet has always been in a state flux. The difference to the past is that since the industrial revolution, the changes are now also increasingly caused by human activity. The release of greenhouse gases in particular promotes the warming of the atmosphere and the oceans. Some experts even predict an increase of up to 4.8 degrees by the end of the 21st century. The result of such a development, apart from environmental catastrophes that are difficult to predict, would be a gigantic migration of populations. CO2 emissions must be reduced: it is five minutes to twelve. The harbingers of disaster have already reached us.