Satellite-based Remote Sensing for Measuring the Earth’s Natural Capital and Ecosystem Services

Nature as the foundation of sustainable development Sustainable use and management of the Earth's natural resources is a key target for nations that have ratified the UN Convention on Biological Diversity. It is also increasingly recognised as critical for sustainable business practices. Governments and the private sector therefore need to understand: 1. What elements of nature are currently present on the planet; 2. What benefits they provide for people; 3. How they are being affected by human activity and the current global environmental change crisis. This knowledge is vital to generate and implement effective environmental policies and mitigation strategies, and ultimately support sustainable development. We summarise here how remote sensing data can be used to provide this information at a national level, in a timely and cost-effective manner; full details can be found in our report. One means of quantifying natural resources is to use the concepts of Natural Capital and Ecosystem Services. Analogous to financial accounting, Natural Capital is the stock of environmental assets – land, air, water, species, habitats and ecosystems – that generates a flow of benefits, or 'dividends', to human beings in the form of Ecosystem Services – such as food, fuel, soil production, pollination, nutrient cycling and climate regulation. On one hand, some 'stocks' (the discrete building blocks of Natural Capital) and 'flows' (the ecosystem goods and services that flow from these stocks) are simple quantities, such as the amount of forest present in an area of interest and the annual primary productivity associated with this forest. On the other hand, some flows can consist of complex processes, such as the coastal protection afforded by mangroves against floods and hurricanes, or water and nutrient cycling. Some stocks and flows cannot be discretely categorised, for example water can be a stock, good or service, and they can be renewable or non-renewable. Potential of satellite-based remote sensing Traditional, ground-based accounting and monitoring techniques are mostly unsuitable to examine the state of, and changes in, Natural Capital and Ecosystem Services at a large scale. Problems with poor replicability and comparability between observers, and the sheer impossibility of covering the entire Earth in a time-and cost-effective manner, make in situ monitoring largely inadequate for the task. Conversely, satellite-based remote sensing has the potential for cost-efficient global monitoring of Natural Capital and Ecosystem Services from global to local scale: there is a plethora of free data available, which are mostly …