The IUCN Urban Nature Indexes are intended to help policymakers, stakeholders and local communities understand their impacts on nature, set science-based targets for improvement, and monitor progress using science-based measures.

  • Introduction
  • Methodology
  • Framework
  • Q & A


Measuring and monitoring are essential to the effective management of natural capital by cities. Qualitative and quantitative indicators can convey valuable information on the status and trends of natural capital stocks, the flows of services they generate, the efficacy of conservation measures, and the impacts of urban consumption on nature globally. In recent years, a plethora of monitoring systems have been developed with different methodologies and approaches. This has resulted in a ‘paradox of choice’ and limited meaningful comparison of measurements over space and time.

To streamline data collection and optimise data utility, there is a need for greater harmonisation and standardisation of indicators. There is a need for a comprehensive system of indicators, flexible enough to cater to a wide range of users, but firm enough to facilitate comparative measurement. The need is somewhat urgent given the accelerated loss of biodiversity worldwide, the extraordinary potential for cities to ameliorate or exacerbate the crisis, the imperative to strengthen urban resilience in the face of climate change, and the necessity for all institutions to make measurable contributions to targets in the post-2020 global biodiversity framework. As a standard-setting organisation with a broad membership base, the International Union for Conservation of Nature (IUCN) is well placed to lead such a process.

In September 2018, IUCN launched the Urban Alliance – a broad coalition of IUCN constituents working towards “a world in which nature thrives in cities, delivering solutions to multiple environmental, social and economic challenges.” With the financial support of Arcadia – a charitable fund of Lisbet Rausing and Peter Baldwin, the IUCN Urban Alliance committed to developing the IUCN Urban Nature Indexes (UNI) to measure the ecological performance of cities. The UNI was intended to bring together existing indicators and data sources to create a single coherent yet flexible tool of value to local governments.

A two-year development process ensued. It entailed multiple workshops, webinars, and consultations. It involved scores of experts from local governments and IUCN constituencies. From the process, emerged 30 indicator topics nested within six themes, constituting the first public version of the UNI and the subject of this report.

While local governments are the primary intended users, the results generated will be of interest to anyone concerned with the relationship between cities and nature, and its implications for human health and wellbeing.

To expedite the rollout of the UNI, IUCN has built an interactive digital platform to present the indicators, provide implementation guidance, and share the results of participating cities.

The IUCN Urban Nature Indexes can be found here.

In June 2023, IUCN organised a series of webinars to present the IUCN Urban Nature Indexes (UNI) and its web-platform, in collaboration with the Urban Biodiversity Hub (UBHub).

The recordings of the webinars can be found here (English) and here (Spanish).