Cities & Nature - Understanding the Interlinkages of Climate Risk, Biodiversity Loss, and Rapid Urbanization as a Tool for Ecosystem-based Adaptation at the Urban Scale

Biodiversity and natural ecosystems are often perceived as diametrically opposed to urban life and cities. This dichotomy is not only false, but prejudicial - in reality, these issues are intrinsically linked.

Firstly, biodiversity and urban life both require land. Cities without adequate urban planning instruments have more risk of sprawling at low density, thereby needing more land and increasing the risk of encroachment on natural habitat. As highlighted in “Cities and Nature: Planning for the Future”, presented by UN-Habitat at the 15th Conference of Parties of the Convention on Biological Diversity, “over 90% of the cities in the world’s 36 biodiversity hotspots are expanding in direct conflict with biodiversity and climate risk. The conversion of natural habitat for human habitation is accelerating, with 290,000 sq km of natural habitat likely to be lost to urban growth between 2000 and 2030.” This alarming rate of urban expansion into biodiversity hotspots represents an imminent threat to global ecosystems, demanding urgent and coordinated action from city planners, policymakers, and conservationists alike. The window for intervention is rapidly closing, making it imperative to implement innovative urban planning strategies that balance human needs with biodiversity conservation.

Secondly, biodiversity and natural habitats offer cities Ecosystem Services, which are often overlooked by citizens and decision-makers. These services protect cities against climate-change risks. Lack of clarity about where habitat loss is occurring at the local scale—particularly at the less-regulated peri-urban edge—makes it difficult to mitigate and to make informed decisions on where and how to urbanize to conserve high-value biodiversity areas and mitigate the effects of the climate crisis. Furthermore, once urbanized, it is harder and more expensive to retrofit and restore land into natural habitat. Many nature-based solutions can be implemented within the city, particularly in green and public spaces, to regenerate ecosystems and create more connectivity amongst them. However, in most cases, the value of Ecosystem Services is far higher for existing natural habitat than for restored or retrofitted habitat.

UN-Habitat and U Penn are developing a modular projection tool which, combined with other planning processes, can support decision-makers at the local level to make informed decisions on how to regulate urban form in their territories. This approach pairs AI, machine learning and ground-truthing to assess climate and biodiversity risk at the urban and regional scale. In this event, the findings of research developed in the metropolitan region of San Jose, Costa Rica will be presented. In addition, there will be a discussion on the challenges of achieving the urban targets set forth by the Kunming-Montreal Global Biodiversity Framework, in biodiverse hotspot zones in the Latin American and Asia Pacific.