Accurately predicting the ecological effects of a warming planet is essential for lessening ongoing economic and societal harm. However, the potential impact of global temperature rise predicted for Earth by the end of the 21st century cannot be studied on the scale of human history alone. Fortunately, essential real-world data on the outcome of rapid and extreme warming is preserved in our planet’s deep-time rock record. Approximately 95 million years ago, Earth transitioned through an interval of global change known as the Cretaceous Thermal Maximum (KTM) with profound repercussions. Global temperature increase during the KTM matches predictions for Earth's near term, making the event a critical case study for our planet’s imminent future. Research demonstrates that during the KTM, 80% of marine life went extinct due to increased ocean temperatures and oxygen starvation. However, scientists do not yet understand the impact of warming on land. Our team of Earth and Life scientists will address fundamental questions about the KTM, producing results directly relevant to society's health and economic well-being. The project will generate freely accessible databases of temperature and precipitation records, species diets, migration and range patterns, plant community compositions, and landscape changes. A sustainable network of labs will use these databases to calculate the duration, rate, and magnitude of extinction and recovery and identify factors affecting ecosystem resili