Earth Observations for the SDGs
Governments, industry, and scientists have long recognised the critical importance of Earth observations as an information source in support of many sectors of society. Earth observations (from satellite, airborne, and in-situ sensors) provide accurate and reliable information on the state of the atmosphere, oceans, coasts, rivers, soil, crops, forests, ecosystems, natural resources, ice, snow and built infrastructure, and their change over time, are directly or indirectly necessary for all functions of government, all economic sectors and almost all day-to-day activities of society. Earth observation programmes represent the largest investment globally in relation to applications of satellites by national governments – typically through their national space agencies – recognising their capacity to address such critical challenges as climate change, water availability, food security, natural disaster mitigation, safe and secure transport, energy and resources security, agriculture forestry and ecosystems, coasts and oceans, health issues, and national security.
In adopting the 2030 Agenda for Sustainable Development, world leaders recognised the important role that Earth observations and geospatial information could play in making the whole framework feasible through the provision of essential evidence, including the tracking of Indicators over time, and supporting the implementation of solutions to reach specific Targets. Effective use of the information in Earth observations can have a transformational impact on many of humanity’s most significant challenges, such as helping scientists globally, resource and planning managers and politicians better monitor and protect fragile ecosystems, ensure resilient infrastructure, manage climate risks, enhance food security, build more resilient cities, reduce poverty, and improve governance, among others.
The CEOS database of Missions, Instruments, and Measurements (MIM) notes that the world’s space agencies are currently operating or planning more than 300 different satellite missions, carrying over 900 different instrument payloads, spanning a diverse range of measurements of atmosphere, ocean, and land, supporting hundreds of applications related to matters that can affect the lives of citizens. Many of the datasets resulting from these missions are openly available through the GEOSS Common Infrastructure (GCI: http://www.geoportal.org) coordinated under the auspices of GEO. In addition, privately funded EO missions, including large constellations of smaller satellites with the capability to provide frequent coverage or repeat measurements, are rapidly increasing in number in recent years. Accordingly, the uptake of satellite data in support of National Statistical Offices (NSOs) and by UN agencies is increasing, made easier by:
- the availability of an increasing array of data streams of suitable characteristics and accuracy;
- the arrival of affordable technical solutions to address the size and complexity of such data;
- and the need to evolve from traditional statistical approaches to more measurement-based solutions as some challenges – including in relation to the environment and human populations – become more pressing, and with the need for more accurate, spatially explicit, and frequently updated evidence.
Whilst the nature of satellite-based measurements varies greatly across the many mission types and their applications, a number of common characteristics are driving their demand in support of global governance and derivation of Indicator information:
Scale: satellites can provide data on all scales from local to national, regional and even global. Indeed, they are likely the only source of global information for many parameters; depending on the application and resolution, large area (even global) datasets can be derived from satellites in relatively short timeframes, from daily to annually as needed and as the technology permits – allowing rapid refresh of Indicator information day and night, in all weather conditions;
Long time series and continuity: the ongoing acquisition of data by satellites systematically and over long periods of time, with some mission series dating back to the 1970s and planned up to 2030 or more, provides governments with unique evidence with which to track progress, including the establishment of baselines for the determination of future trends, for monitoring and compliance of agreements, for improved predictions, and for management and mitigation;
Consistency and comparability: satellites provide the means for the effective comparison of results among different countries which may otherwise suffer from lack of standardisation in measurements or methods, impeding attempts to derive meaningful comparisons or regional/global statistics;
Diversity of measurements: advances in science and in instrumentation have resulted in an increasingly diverse array of EO satellite missions with dozens of geophysical parameters being measured on a daily basis from a range of different satellite orbits. In the field of climate change alone, CEOS has identified that of the ~ 55 Essential Climate Variables (or ECVs) more than half have a major contribution from satellite observations or simply would not be feasible without satellites (such as polar ice extent, and global sea level).
Complementarity with traditional statistical methods: while EO datasets can be used to monitor directly some specific Indicators of SDGs, they can also offer a unique and complementary source of information to cross-check the validity of in-situ data measurements (such as survey and inventory data), communicate and visualize the geographic dimensions and context of the Indicators as needed, and provide disaggregation of the Indicators where appropriate.
Free and open data is on the increase: not all nations are able to develop and launch their own Earth observation satellites, with a relatively small (but growing) number having the capacity to do so. Hence the availability of the data from these missions, for all nations, is of fundamental importance to their uptake and global impact. US mission data has long been freely available, and with the advent of the free and open data policy of Europe’s Copernicus programme of multiple satellite data streams, the prospects for access to the EO data required by developing countries have improved considerably.
High performance computing and cloud storage and processing capabilities are making it simpler to handle and apply EO satellite datasets which can be large and complex. And space agencies are prioritising efforts to further remove the burden on potential users by making more data ‘analysis ready’ (analysis ready data or ARD).
An analysis by GEO and CEOS has identified specific Targets and Indicators that can be supported by Earth observations, summarised in Figure 2.
For readers unfamiliar with the details of the individual Goals, Targets and Indicators listed, these can be identified from this document.