The annual clock of the seasons – winter, spring, summer, autumn – is often taken as a given. But our new study in Nature, using a new approach for observing seasonal growth cycles from satellites, shows that this notion is far too simple. We present an unprecedented and intimate portrait of the seasonal cycles of Earth's land-based ecosystems. This reveals "hotspots" of seasonal asynchrony around the world – regions where the timing of seasonal cycles can be out of sync between nearby locations. .....