Understanding how species and ecosystem responds to environmental variation and change is a key challenge for ecology. Due to the severe changes in global climate predicted for the 21st century, there is an urgent need for knowledge of the ecological effects of climate change. Such knowledge will help develop sound strategies for natural resource management. This IRSAE theme focusses on the study of effects of climate change from the individual to the ecosystem level across spatial and temporal scales. Such studies may be based on long-term observations, experiments, modelling and can be integrated with other drivers of ecological change like biotic interactions or land use change.