Earth System Science (ESS)

“Everything is connected” is a phrase commonly heard in everyday life. “Think global, act local” is a slogan often uttered by environmentalists. Both statements are at the heart of Earth System Science (ESS).

ESS is a new, deeply interdisciplinary field that seeks to understand how our planet – including humans – functions as an integrated whole. The focus is therefore less on individual Earth components – such as the atmosphere (air and gases), hydrosphere (water), lithosphere (land), cryosphere (ice and snow), and biosphere (life) – and more on their interactions: changes in one component often have ripple effects that can propagate to many others.

ESS has emerged as the main vehicle to tackle global change, which includes climate change but also land degradation, water scarcity, and food insecurity. Tackling global change problems involves studying human-landscape interactions from local scales to the entire globe, leveraging fundamentals of mathematics, physics, chemistry, and biology, and overcoming technical challenges associated with the collection, processing, modelling, and interpretation of Earth System data.

At McGill, ESS reaches across three departments: Atmospheric and Oceanic Sciences, Earth and Planetary Sciences, and Geography.