Suarez, D.C. & Dempsey, J. (2018). Ecosystem Services. In M. Hulme, N. Castree & J. Proctor (Eds.), Companion to Environmental Studies. New York: Routledge, pp. 173-178 Ecosystem Services Daniel Chiu Suarez and Jessica Dempsey What are ecosystem services? Across virtually all indicators, biodiversity loss continues to worsen on a planetary scale (GBO-4 2014). From species extinction and habitat destruction to overharvesting and climate change, the situation is dire. This growing sense of socio-ecological crisis and widespread institutional failure has prompted many in the environmental movement to look with renewed urgency toward new ideas, new strategies, and ultimately a new way forward for biodiversity conservation. Over the past two decades, one such framework has been vigorously promoted as offering this new way forward: ecosystem services. The Millennium Ecosystem Assessment defines ecosystem services simply as “the benefits people obtain from ecosystems” (MA 2005). The concept expresses in measurable, often monetary terms the economic values encompassed in biodiversity: mangos, clean drinking water, weekend hikes, flood protection, pharmaceuticals, two-by-fours, and so on ad infinitum. In a set of foundational reports authored by over 1,300 experts from around the world, the MA sorted these “services” into what became a classic four-category classification: (i) provisioning services such as food, freshwater, and timber, (ii) regulating services such as climate, flood, and disease attenuation, (iii) supporting services such as nutrient cycling, primary productivity, and soil formation, and (iv) cultural services such as educational, aesthetic or spiritual fulfilment (Figure 1). While typologies for ecosystem services vary, they all express a particular way of making sense