Earth is a cosmic rarity: a known life-sustaining planet. The one we live on. The number of us the planet can support—Earth’s carrying capacity—is determined by the health of its intertwined natural systems, making the pervasive environmental impact of climate change an existential threat.
International governing bodies, keenly aware of this reality, have agreed on sustainability goals, outlining the collective actions needed to support long-lasting planetary habitability in an epoch of climate change. Earth-observing satellites are key for monitoring progress towards many these global goals. Many laws and international policies have come to rely on satellite data as both compliance and tracking tools—but knowledge gaps remain.
In a January 2024 Remote Sensing of Environment paper, a cadre of former Landsat Science Team members posit that realizing progress towards global sustainability goals would be substantially aided by 13 essential, regularly-updated global data products made with open-access and freely-available Landsat and Sentinel-2 datasets. Additionally, with an eye to the future and an acknowledgment of state-of-the-art data handling, processing, and methodologies, further desirable and aspirational data products are offered.
“Currently information needs are not being met to the detriment of global change science and environmental management,” the authors write. While at the same time, “many potential benefits of the substantial investments into satellites sensors and ground segments have not yet been realized.”
Pulling it Together: 13 Essential Global Data Products
To fill these knowledge gaps and maximize the return on investment of government Earth observation infrastructure, the authors identify 13 essential global data products: land cover, land cover change, burned area, forest lost, vegetation indices, phenology, dynamic habitat indices, albedo, land surface temperature, snow cover, ice extent, surface water extent, and evapotranspiration.
By triangulating between information needs, satellite capabilities, and the state-of-the-science, the authors were able to hone their list of most needed data products. These data products were deemed essential because they are required by large data user communities and international governing initiatives (e.g. the United Nation’s Sustainable Development Goals and Global Biodiversity Framework; the Paris Agreement, Essential Climate Variables).
Food security, ecosystem service continuation, sustainable natural resource management, biodiversity conservation, climate change adaptation, and natural hazard mitigation all depend on accurate data inputs for understanding, and action. The data products must be simultaneously scientifically robust, socially-relevant, and regularly updated to best inform policymakers.
Answers Within Reach
Fortunately, combined data from the freely available, medium-resolution Landsat and Sentinel-2 satellites could provide the information needed to make the regularly updated, 13 essential global data products a reality. Importantly, Landsat and Sentinel-2 are global, available for decades past, and have spatial resolutions that work at the management-scale (think farm fields, forest stands, and urban subdivisions).
Echoing the language of the1966 Interior Department press release that helped make Landsat and space-based Earth observation a reality, the authors state: “The time is right for the production of a suite of essential medium-resolution, global, systematic products.”
The confluence of many factors have led to this moment. Government investment into the Landsat and Sentinel-2 science-grade data streams provides the robustly calibrated and atmospherically corrected information needed to create the 13 essential global data products. The combination of Landsat and Sentinel-2 data sets allows the “uptempo” data collection cadence needed for regular updates, enabling, as the authors write, “timely information for pressing global problems.” And the two-plus decade precedent of coarser global data products from sensors like MODIS and VIIRS has cemented the open science approach of community-endorsed data product algorithms.
The authors cite a number of large-area data products that are already systematically derived from Landsat and/or Sentinel-2 as stepping stones towards their vision, like the USGS National Land Cover Database, USDA’s Cropland Data Layer, OpenET, Global Surface Water Explorer, Global Human Settlements Layer, GEOGLAM, Global Forest Watch, and CORINE Land Cover.
While all of the pieces are in place to produce and regularly update the 13 essential global data products, the will and funding for such a large undertaking must still be mustered. The guaranteed long-term availability of consistent and persistent data is critical to such efforts to characterize the current state and changes to Earth’s biosphere, cryosphere, and hydrosphere. To that end, satellite data continuity with the launch of Sentinel-2c (in Sept. 2024), and forthcoming Sentinel-2d (2028) and Landsat Next (early 2030s) is paramount.
For more details on the 13 essential global data products, as well as additional desirable and aspirational data sets, please see (open access):
Radeloff, Volker C., David P. Roy, Michael A. Wulder, Martha Anderson, Bruce Cook, Christopher J. Crawford, Mark Friedl, Feng Gao, Noel Gorelick, Matthew Hansen, Sean Healey, Patrick Hostert, Glynn Hulley, Justin L. Huntington, David M. Johnson, Chris Neigh, Alexei Lyapustin, Leo Lymburner, Nima Pahlevan, Jean-Francois Pekel, Theodore A. Scambos, Crystal Schaaf, Peter Strobl, Curtis E. Woodcock, Hankui K. Zhang, and Zhe Zhu. 2024. “Need and vision for global medium-resolution Landsat and Sentinel-2 data products.” Remote Sensing of Environment 300: 113918. https://doi.org/10.1016/j.rse.2023.113918
