Abstract
Earth observation by satellite began a few years after the launch of the first artificial satellites. The first instruments aboard these satellites were designed for imaging purposes, mainly to visualize cloud systems. Soon, more sophisticated instruments were able to measure atmospheric temperature and humidity, for better weather forecasting. Today, a large number of satellites help to monitor climatic parameters such as temperature, sea level, soil moisture and vegetation. We offer an overview of the contribution of space observation to the monitoring of climatic processes and climate change.