A new model that captures nature's contributions to human wellbeing and compares them to peoples' future needs shows that, within the next thirty years, as many five billion people could face water and food insecurity - particularly in Africa and South Asia. Hundreds of millions more could be vulnerable to increased risks of severe coastal storms. These are the results of the first-ever global modeling of nature's contributions to people. "The paper by [Rebecca] Chaplin-Kramer [and colleagues] provides a unique and deeply worrying picture of the societal burdens of losing nature," Patricia Balcanera writes in a related Perspective. Human well-being is dependent upon nature's contributions - which include ecosystem services that ensure clean water or crop pollination. However, increasing impacts on global environments have led to declines in these crucial systems. To bring attention to this, the Intergovernmental Platform on Biodiversity and Ecosystem Services Global Assessment recently released their first report, which evaluated the status of nature's contributions. Even so, according to the authors, an urgent need remains to determine where and how nature's contributions matter most to people - and who's most at risk should they cease. To address this, Chaplin-Kramer et al. developed a high-resolution, global-scale spatial model, which uniquely captures both the 'supply-side' (nature's contributions) and 'demand-side' (people's needs) of ecosystem services. They evaluated trends in water quality, crop pollination and coastal protection in three potential future scenarios. The results show that where people's needs for nature are greatest, nature's ability to meet those needs is declining. By 2050, billions will be at risk of increased water pollution, severe coastal storm vulnerability and food insecurity related to deficient crop pollination. What's more, developing countries in Africa and South Asia are expected to bear the brunt of these impacts.