Biodiversity loss is a major environmental challenge facing humankind. Despite some local successes, biodiversity is on the decline globally and this loss is projected to continue. Continuing with business as usual may have far-reaching adverse implications for human well-being, security and economic growth. This chapter summarises the considerable benefits and often hidden values of biodiversity and the ecosystems of which it is a part. It then looks at trends in several indicators of biodiversity – species abundance (e.g. mean species abundance or MSA), threatened species, forest area (deforestation) and marine fish stocks – and the implications of business-as-usual trends continuing to the year 2050 under the OECD Environmental Outlook Baseline scenario. The chapter provides an overview of the different policy instruments available for biodiversity conservation and sustainable use, ranging from regulations to market-driven approaches, such as payments for ecosystem services (PES). Some more ambitious policy scenarios are examined – such as the implications of meeting the Aichi Biodiversity Target under the Convention on Biological Diversity (CBD) to expand the global protected area network to at least 17% of terrestrial land by 2020. Possible synergies and trade-offs of meeting climate mitigation goals (through different bioenergy and land use scenarios, for example) and the impacts on biodiversity are also examined. The chapter concludes with a discussion of key needs for further policy action in the context of biodiversity and how this links to the broader green growth agenda.