Natural capital is a term for the habitats and ecosystems that provide social, environmental and economic benefits to humans. Scotland has a wide range of these habitats and ecosystems - each of which makes a unique contribution to the wellbeing of those who live and work in Scotland.
The Natural Capital Asset Index (NCAI) is a composite index which tracks changes in the capacity of Scotland's terrestrial ecosystems to provide benefits to people. It does not include the benefits from the marine environment (although a feasibility study assessing whether this is possible was carried out in 2019).
The NCAI does not include monetary values but is composed in a way which reflects the relative contribution of habitats to human wellbeing. A set of experimental Natural Capital Accounts looking at the contribution of Scotland’s natural capital in monetary terms by the Office for National Statistics (ONS) was first released in 2019 and updated in 2022. A full description of the differences between these Scottish Accounts and the NCAI can be found in the Natural Capital Asset Index comparison document.
Historically, Scotland's natural capital deteriorated until the 1990s. Most habitats were declining during this period, especially bogs and grassland. Evidence from the NCAI suggests that Scotland's potential to deliver ecosystem services has grown slightly over the past 15 years and now is at its highest level since 2000, recovering from a low in 2012. Further details can be found in the Natural Capital Asset Index 2022 summary.
The Natural Capital Asset Index is included as a measure for the National Indicator 'Increase our natural capital' in the National Performance Framework. Recently released data for the year 2020 suggests that Scotland’s stock of Natural Capital is being maintained.
The capacity of ecosystems to provide benefits fluctuates over time due to changes in habitat quantity and quality. We track habitat quantity in the NCAI using what we know about land cover change in Scotland. Habitat quality is tracked using 38 separate indicators which rely on datasets gathered by a range of public organisations and citizen science schemes.
The full Natural Capital Asset Index 2022 detailed model data 2020 used to calculate the NCAI is available online, a full history of the development of the NCAI and the theoretical underpinnings that support it can be found in our journal article which was published by international journal Ecological Indicators.