Fossil leaves can tell us about past climates and environments. By studying plant traits and where plants grow, scientists can figure out what ancient ecosystems were like. These methods are very accurate and have been used from the time of dinosaurs to recent history. However, factors like leaf lifespan and plant family can affect the results. Researchers are working on improving these methods by considering plant family traits, expanding datasets, and using computer programs to measure leaf traits. This will make plant-based methods even better at telling us about ancient climates and environments.