Global long-term prosperity and the well-being of future generations are in jeopardy, as biodiversity loss and the collapse of critical ecosystems not only threaten the environment, but also raise risks for the economy, public health, national security, and world stability. At the 2024 United Nations Biodiversity Conference, currently taking place in Cali, Colombia, leaders must finally meet this crisis with the level of political commitment and funding that it warrants.Biodiversity is often understood in terms of the variety of life on Earth – the number of species of plants, animals, and microorganisms. Its significance cannot be overstated. Biodiversity underpins the ecosystem services that sustain human life, such as water purification, flood control, and climate regulation. The rapid decline of species and ecosystems – 1mn plant and animal species are on the brink of extinction – thus amounts to an existential threat.If left unaddressed, biodiversity loss will accelerate climate change and amplify its consequences, contributing to more natural disasters and market shocks. It will also leave the agricultural systems increasingly vulnerable to hazards – from pests and pathogens to extreme weather – and deplete the ocean of critical fish stocks. This will affect both the price and availability of food, causing scarcity in the Global South and compounding insecurity in already-fragile societies.These trends will leave a growing number of people with little choice but to flee their homes in search of better living conditions.As the planet’s total habitable area shrinks, and competition for resources grows, conflict will become all but inevitable.Biodiversity loss also threatens public health, which is inextricably linked to the ecosystems that surround us. Many diseases can be tied directly to changes in biodiversity. As the destruction of habitats forces wildlife into closer contact with human populations, the risk of zoonotic diseases like Covid-19 rises.To prevent such a future, all countries must recognise biodiversity loss as a security issue. This means integrating biodiversity considerations into defence and foreign policymaking. And it means financing the response – including investments in practices that protect ecosystems, and ambitious measures to address the root causes of biodiversity loss, such as habitat destruction and climate change – as robustly as they would for any other security crisis.The consequences of biodiversity loss know no borders. Countries must work together to protect critical habitats, enforce environmental regulations, and promote sustainable development practices.As such, multilateral groups, such as the High Ambition Coalition for Nature and People, should continue to take the lead in forging international agreements and action plans that establish biodiversity conservation as a cornerstone of global security. Policymakers must continue to focus on working to meet the biodiversity framework’s “30x30” target, by encouraging and facilitating government action to protect 30% of the planet’s land and ocean by 2030. Furthermore, members from the Global North should increase financial support for countries in the Global South to implement necessary designations, specifically by meeting their commitment to deliver at least $20bn of nature finance annually by 2025.Finally, governments must engage and inform the public. Education and awareness campaigns that explain the importance of protecting biodiversity can empower individuals and communities to advocate for policies that protect natural resources, thereby helping to generate the necessary political will.If an enemy state threatened the economy, public health, national security, and global stability, we would throw everything we had at it to defend ourselves. The biodiversity crisis is no different.