Many scientists are claiming that the Sixth Mass Extinction of species is underway. On top of the direct negative impacts on human well-being, one reason to worry is that biodiversity provides numerous ecosystem services that are essential to the economy. Therefore, this paper proposes a global macroeconomic growth model that takes into account the dynamics of biodiversity and the ecosystem services it provides. To do this, I bring together the latest advances in biology on the “Species-Area” and “Biodiversity-Ecosystem Functioning” relationships. I also put forward a new method for estimating sectoral production functions, using input-output tables and their environmental extensions. Importantly, preferences are non-homothetic: there is a minimum subsistence food level. My main results focus on optimal land use on a macroeconomic scale. I show that this value is determined by the trade-off between the total marginal costs and marginal benefits of agricultural production. The costs are broken down into the direct costs of land conversion and the social (productive) costs associated with the loss of ecosystem services. Because of the need for water supply (regulated by biodiversity) in the industrial sector and the non-homothetic preferences, the optimal land use significantly decreases with the development stage of an economy. Its optimal level is half as high (18% vs. 39%) in a developed country as in a less developed one.