Summary

This report, Thriving on Our Changing Planet: A Decadal Strategy for Earth Observation from Space, of the National Academies of Sciences, Engineering, and Medicine’s 2017-2027 decadal survey for Earth science and applications from space (ESAS 2017) is the second such decadal survey of the National Academies. This summary provides a comprehensive overview of the present decadal survey and its key findings and recommendations; however, readers should note that space limitations do not permit a detailed discussion of each of the report’s 17 findings and 20 recommendations.

EARTH OBSERVATION FROM SPACE: A TRANSFORMATIVE CAPABILITY

From the time of the earliest humans, knowledge about Earth has been fundamental to our fate and prospects. Over the past 60 years, particularly rapid progress has been achieved in acquiring such scientific and practical knowledge, due in large part to the special perspective provided by “satellite-based Earth observations.”

The vantage point of space enables us to see the extent to which Earth’s ever-changing processes influence our lives. These processes operate at local spatial scales, such as the flows of rivers that provide freshwater and the weather and climate conditions that determine crop yields, as well as at global spatial scales, such as changes in the ocean currents that impact commercial fishing and contribute to global change and climate variability. The space-based vantage point also ensures that we can observe processes occurring over a wide range of time scales, from the abrupt (such as earthquakes) to the decadal (such as growth and shrinkage of the world’s great ice sheets), and at all time scales in between.

Empowered by this perspective, we are coming to recognize the complex and continually changing ways by which Earth’s processes occur, along with the critical roles their observation and understanding play throughout our lives.

Finding 1.1: Space-based Earth observations provide a global perspective of Earth that has

• Over the last 60 years, transformed our “scientific understanding” of the planet, revealing it to be an integrated system of dynamic interactions between the atmosphere, ocean, land, ice, and

• human society across a range of spatial and temporal scales, irrespective of geographic, political, or disciplinary boundaries.
• In the past decade in particular, enabled “societal applications” that provide tremendous value to individuals, businesses, the nation, and the world. Such applications are growing in breadth and depth, becoming an essential information infrastructure element for society as they are integrated into people’s daily lives.

THRIVING ON OUR CHANGING PLANET

This ability to observe our planet comprehensively matters to each of us. Earth information—for use in Internet maps, daily weather forecasts, land-use planning, transportation efficiency, and agricultural productivity, to name a few—is central to our lives, providing substantial contributions to our economies, our national security, and our personal safety. It helps ensure we are a thriving society.

The Earth information we have come to rely on throughout our daily lives is the result of a sustained commitment to both exploratory and applied Earth science, and to what has become a sophisticated national and international infrastructure of observing systems, scientific research, and applications. A particular strength of the Earth science and applications field is the extent to which curiosity-based science is inextricably integrated with applications-oriented science and societal benefits. Ongoing commitment to this inspirational and practical science has returned benefits to society many times over, and will continue to do so with further support.

Among the most intellectually and practically important revelations from the past 60 years of space-based observation is the extent to which Earth is changing, in multiple ways and for many reasons. Daily changes, such as weather, were obvious to even the earliest humans, even if not explainable. Longer-term changes, particularly those occurring on global scales, are only now becoming understood and gaining public recognition. Some of these changes are climate related, such as alteration of the El Niño Southern Oscillation (ENSO), but many are not. In addition to climate, changes in air quality, water availability, agricultural soil nutrients, and other Earth resources are being driven largely by human actions. Successfully managing risks and identifying opportunities associated with these changes requires a clear understanding of both the human-driven and the natural processes that underlie them.

A CHALLENGING VISION FOR THE DECADE AND BEYOND

A changing Earth is one we can never understand just from past experience. Its evolving and emerging characteristics must be continually explored through observation. Our scientific curiosity must seek and reveal the new and altered processes that will result from change, if we are to continue applying our knowledge effectively for society’s benefit. Decisions we make this decade will be pivotal for predicting the potential for future changes and for influencing whether and how those changes occur. Embracing this new paradigm of understanding a changing Earth, and building a program to address it, is our major challenge for the coming decade and beyond.

Recommendation 2.1: Earth science and applications are a key part of the nation’s information infrastructure, warranting a U.S. program of Earth observations from space that is robust, resilient, and appropriately balanced. NASA, NOAA, and USGS, in collaboration with other interested U.S. agencies, should ensure efficient and effective use of U.S. resources by strategically coordinating and advancing this program at the national level, as also recommended in the 2007 Earth Science and Applications from Space (ESAS) decadal survey.

This context of both societal need and intellectual opportunity provided the basis for developing the Earth observation program proposed in this report. Society’s fundamental desire to thrive, the expanding scientific knowledge needed to support that desire, and the growing capacity to apply that knowledge are all central motivations for this committee’s recommendations. Embracing the goal of understanding Earth in pursuit of this vision—to thrive on our changing planet—motivates a new paradigm for the coming decade and beyond.

A STRUCTURED APPROACH TO ACHIEVING PROGRESS

The next decade is one in which progress will not come easily. Financial and human resource constraints are likely to present challenges to progress (Chapter 1). Succeeding compels NASA, NOAA, and USGS to develop, adopt, and implement strategies to advance both technology and programmatic processes. The committee recommends eight elements (numbered only for identification) of a suggested strategic framework (Chapter 2):

1. Commit to sustained science and applications;
2. Embrace innovative methodologies for integrated science/applications;
3. Amplify the cross-benefit of science and applications;
4. Leverage external resources and partnerships;
5. Institutionalize programmatic agility and balance;
6. Exploit external trends in technology and user needs;
7. Expand use of competition; and
8. Pursue ambitious science, despite constraint.

The challenges ahead, and the need for innovative and strategic thinking to overcome them, are reflected in the following community challenge.

The committee believes that meeting the challenge described earlier will motivate the scientific community to pioneer novel approaches in how it conducts its scientific research, with an emphasis on programmatic and technological innovation to accomplish more with less, with greater attention to the potential benefits of domestic and international partnerships along with the growing capability of commercial sources (Chapters 3 and 4).

The committee conducted its work in close collaboration with the decadal survey’s five study panels, each interdisciplinary and together spanning all of disciplines associated with Earth system science. The survey process is summarized in Figure S.1. It was designed to converge—from a large number of community-provided possibilities—to a final, small set of Science and Applications Priorities (shown in blue) and Observing System Priorities (shown in green) that are required to address the nation’s Earth science and applications needs. This process assumed that the existing and planned instruments in the Program of Record (POR) are implemented as expected.

ESTABLISHING SCIENCE AND APPLICATIONS PRIORITIES

Starting from an initial set of 290 community-submitted ideas, the committee, working with the five interdisciplinary panels, narrowed this large set of ideas to a set of 35 key Earth science and applications questions to be addressed over the next decade. Together, these questions comprehensively address those areas for which advances are most needed in both curiosity-driven and practically focused Earth science and the corresponding practical uses of Earth information. To identify the observational capabilities required to answer these questions, the committee then defined a set of underlying science and applications objectives, evaluating and assigning each to one of three prioritization categories: Most Important (MI), Very Important (VI), and Important (I).

This process informed the committee’s Recommendation 3.1 that NASA, NOAA, and USGS pursue the key science and applications questions summarized in Table S.1 (and described in more detail in the body

TABLE S.1 Science and Applications Priorities for the Decade 2017-2027 (see note following table for description)

NOTE: The highest-priority questions (defined as those associated with Most Important objectives) are listed in full; other questions associated with Very Important or Important objectives are briefly summarized. No further priority is assumed within categories, and the topics are listed alphabetically. Letter and number combinations in parentheses refer to the panel (H = Hydrology, W = Weather, E = Ecosystems, C = Climate, S = Solid Earth) and the numbering of each panel’s questions. Complete versions of this table are provided in Table 3.2 and in Appendix B.

of the report; complete versions of this table are provided in Table 3.2 and Appendix B). These questions address the central science and applications priorities for the coming decade.

Recommendation 3.1: NASA, NOAA, and USGS, working in coordination, according to their appropriate roles and recognizing their agency mission and priorities, should implement an integrated programmatic approach to advancing Earth science and applications that is based on the questions and objectives listed in Table 3.2, “Science and Applications Priorities for the Decade 2017-2027.”

By pursuing these priorities, important advances will be made in areas that are both scientifically challenging and of direct impact to how we live. A major component of the committee’s observing program recommendations is a commitment to a set of observation capabilities, outlined in the next section that will enable substantial progress in all of the following science and applications areas:

• Providing critical information on the make-up and distribution of aerosols and clouds, which in turn improve predictions of future climate conditions and help us assess the impacts of aerosols on human health;
• Addressing key questions about how changing cloud cover and precipitation will affect climate, weather, and Earth’s energy balance in the future, advancing understanding of the movement of air and energy in the atmosphere and its impact on weather, precipitation, and severe storms;
• Determining the extent to which the shrinking of glaciers and ice sheets, and their contributions to sea-level rise, is accelerating, decelerating, or remaining unchanged;
• Quantifying trends in water stored on land (e.g., in aquifers) and the implications for issues such as water availability for human consumption and irrigation;
• Understanding alterations to surface characteristics and landscapes (e.g., snow cover, snowmelt, landslides, earthquakes, eruptions, urbanization, land-cover, and land use) and the implications for applications such as risk management and resource management;
• Assessing the evolving characteristics and health of terrestrial vegetation and aquatic ecosystems, which is important for understanding key consequences such as crop yields, carbon uptake, and biodiversity; and
• Examining movement of land and ice surfaces to determine, in the case of ice, the likelihood of rapid ice loss and significantly accelerated rates of sea-level rise, and in the case of land, changes in strain rates that impact and provide critical insights into earthquakes, volcanic eruptions, landslides, and tectonic plate deformation.

In addition, the committee is proposing competitive observational opportunities, also outlined in the next section, to address at least three of the following science and applications areas:

• Understanding the sources and sinks of carbon dioxide and methane and the processes that will affect their concentrations in the future;
• Understanding glacier and ice sheet contributions to rates of sea-level rise and how they are likely to impact sea-level rise in the future;
• Improving understanding of ocean circulation, the exchanges between the ocean and atmosphere, and their impacts on weather and climate;
• Assessing changes in ozone and other gases and the associated implications for human health, air quality, and climate;
• Determining the amount and melt rates of snow and the associated implications for water resources, weather, climate, flooding, drought, and so on;
• Quantifying biomass and characterizing ecosystem structure to assess carbon uptake from the atmosphere and changes in land cover and to support resource management; and
• Providing critical insights into the transport of pollutants, wind energy, cloud processes, and how energy moves between the land or ocean surfaces and the atmosphere.

The recommended program will advance scientific knowledge in areas that are ripe for discovery and that have direct impact on the way we live today. The knowledge developed in the coming decade, through this science, holds great promise for informing actions and investments for a successful future.

IMPLEMENTING AN INNOVATIVE OBSERVING PROGRAM

Addressing the committee’s priority science and applications questions requires an ongoing commitment to existing and planned instruments and satellites in the POR. The committee’s recommended observing program builds from this, filling gaps in the POR where observations are needed to address the key science and applications objectives for the coming decade. This observing program is summarized in Table S.2 (Table 3.3 in Chapter 3) and in the accompanying Recommendation 3.2. Most observables are allocated to two new NASA flight program elements: a committed group of observations termed “Designated,” along with a competed group termed “Earth System Explorer.” Within these two new flight program elements, eight of the priority observation needs from Table S.2 are expected to be implemented as instruments, instrument suites, or missions. In addition, several observables are assigned to a new program element called “Incubation,” intended to accelerate readiness of high-priority observables not yet feasible for cost-effective flight implementation. Finally, an expansion of the Venture program is proposed for competed small missions to add a focus on continuity-driven observations. Together, these new program elements complement existing NASA flight program elements such as the Venture program.

The foundational observations in Table S.2—the five shown in the “Designated” column that are recommended specifically by the committee for implementation, and the three to be competitively selected from among the identified set of seven “Earth System Explorer” candidates—augment the existing POR and ensure that the survey’s 35 priority science and applications questions can be effectively addressed, to the extent that resources allow. In keeping with the study’s statement of task, specific missions and instruments were not identified, ensuring that the sponsoring agencies will have discretion for identifying the most cost-effective and appropriate space-based approaches to implementing the recommended set of observations. Each of the new NASA flight program elements promises innovative means for using

TABLE S.2 Observing System Priorities (see note following table for description)

NOTE: Observations (Targeted Observables) identified by the steering committee as needed in the coming decade, beyond what is in the Program of Record, allocated as noted in the last three columns (and color-coded) to three new NASA flight program elements (Designated, Earth System Explorer, Incubation; as defined in the accompanying text). Within categories, the targeted observables are listed alphabetically. Targeted Observables included in the original priority consideration but not allocated to a program element are listed at the bottom of the table (see Appendix C for a complete summary).

competition and other programmatic tools to increase the cadence and quality of flight programs, while optimizing cost and risk.

Recommendation 3.2: NASA should implement a set of space-based observation capabilities based on this report’s proposed program (which was designed to be affordable, comprehensive, robust, and balanced) by implementing its portion of the Program of Record and adding observations described in Table 3.3, “Observing System Priorities.” The implemented program should be guided by the budgetary considerations and decision rules contained in this report and accomplished through five distinct program elements:

1. Program of Record. The series of existing or previously planned observations, which must be completed as planned. Execution of the ESAS 2017 recommendation requires that the total cost to NASA of the Program of Record flight missions from fiscal year (FY) 2018 through FY 2027—October 1, 2017 through September 30, 2027—be capped at $3.6 billion.
2. Designated. A program element for ESAS-designated cost-capped medium- and large-size missions to address observables essential to the overall program, directed or competed at the discretion of NASA.
3. Earth System Explorer. A new program element involving competitive opportunities for cost-capped medium-size instruments and missions serving specified ESAS-priority observations.

4. Incubation. A new program element, focused on investment for priority observation capabilities needing advancement prior to cost-effective implementation, including an innovation fund to respond to emerging needs.
5. EarthVenture. Earth Venture program element, as recommended in ESAS 2007, with the addition of a new Venture-continuity component to provide opportunity for low-cost sustained observations.

The committee is confident, based on analyses of technical readiness and cost performed during the study, that the recommended observations have feasible implementations that can be accomplished on schedule and within the stated cost caps. The proposed program was designed both to fit within anticipated budgets (assumed for the purposes of this report to grow only with inflation) and to ensure balance in the mission portfolio among program elements (Figure S.2). As appropriate, candidate instruments and missions were formally subjected to a Cost Assessment and Technical Evaluation (CATE) to assess budget needs. The committee considered management of development cost to be of critical importance to effective implementation of this program, in order to avoid impacting other programs and altering the desired programmatic balance. Should budgets be more or less than anticipated, the report includes decision rules for altering plans in a manner that seeks to ensure the overall program integrity.

ENABLING THE PROGRAM

Finally, none of this happens without “robust supporting programs” at NASA, NOAA, and USGS that provide the enabling resources for developing the recommended space-based observing systems and evaluating the data they produce. In particular, these supporting programs are central to transforming scientific advances into applications and societal benefits. The committee has proposed a variety of programmatic actions intended to improve the ability of each agency to deliver on its space-based observation programs.

Key among these are findings and recommendations associated with the following: ensuring balanced and robust programmatic structures (Findings 4.4 and 4.5); recognizing the importance of sustained land imaging through the USGS Landsat program (Finding 4.10); and leveraging partnering opportunities (such as the European Union’s Copernicus/Sentinel program noted in Recommendation 4.5) that enhance operational efficiencies and ensure that the agencies can accomplish the most possible within their available resources (Finding 4.10; Recommendations 4.5, 4.11, and 4.12).

Finding 4.4: A robust and resilient Earth Science Division (ESD) program has the following attributes:

• A healthy cadence of small/medium missions to provide the community with regular flight opportunities, to leverage advances in technologies and capabilities, and to rapidly respond to emerging science needs;
• A small number of large cost-constrained missions, whose implementation does not draw excessive resources from smaller and more frequent opportunities;
• Strong partnerships with U.S. government and non-U.S. space agencies;
• Complementary programs for airborne, in situ, and other supporting observations;
• Periodic assessment of the return on investment provided by each program element; and
• A robust mechanism for trading the need for continuity of existing measurement against new measurements.

Finding 4.5: Maximizing the success of NASA’s Earth science program requires balanced investments across its program elements, each critically important to the overall program. The flight program provides observations that the research and analysis program draws on to perform scientific exploration, the applied sciences program transforms the science into real-world benefits, and the technology program accelerates the inclusion of technology advances in flight programs. The current balance across these four program elements is largely appropriate, enabling a robust and resilient Earth science program, and can be effectively maintained using decision rules such as recommended in this report. Some adjustment of balance within each program element is warranted, as recommended in this report.

Finding 4.10: Extension of Landsat capability through synergy with other space-based observations opens new opportunities for Landsat data usage, as has been demonstrated with the European Space Agency (ESA) through cross-calibration and data sharing for Sentinel-2. These successes serve as a model for future partnerships and further synergies with other space-based observations.

Recommendation 4.5: Because expanded and extended international partnerships can benefit the nation:

• NASA should consider enhancing existing partnerships and seeking new partnerships when implementing the observation priorities of this decadal survey.
• NOAA should strengthen and expand its already strong international partnerships, by (1) coordinating with partners to further ensure complementary capabilities and operational backup while

• minimizing unneeded redundancy; and (2) extending partnerships to the more complete observing system life cycle that includes scientific and technological development of future capabilities.
• USGS should extend the impact of the Sustainable Land Imaging (SLI) program through further partnerships such as that with the European Sentinel program.

Recommendation 4.11: NOAA should establish itself among the leading government agencies that exploit potential value of commercial data sources, assessing both their benefits and risks in its observational data portfolio. It should innovate new government/commercial partnerships as needed to accomplish that goal, pioneer new business models when required, and seek acceptable solutions to present barriers such as international partner use rights. NOAA’s commercial data partnerships should ensure access to needed information on data characteristics and quality as necessary and appropriate, and be robust against loss of any single source/provider if the data are essential to NOAA core functions.

Recommendation 4.12: NOAA should establish, with NASA, a flexible framework for joint activities that advance the capability and cost-effectiveness of NOAA’s observation capabilities. This framework should enable implementation of specific project collaborations, each of which may have its own unique requirements, and should ensure (1) clear roles, (2) mutual interests, (3) life-cycle interaction, (4) multidisciplinary methodologies, (5) multielement expertise, and (6) appropriate budget mechanisms.

ANTICIPATED PROGRESS WITHIN THE DECADE

In this report, the committee identifies the science and applications, observations, and programmatic support needed to bring to fruition its vision of understanding deeply the nature of our changing planet. With implementation of its recommended plan, the committee expects the following to have been accomplished by the end of the survey decade:

Programmatic implementation within the agencies will be made more efficient by

• Increasing Program Cost-Effectiveness. Promote expanded competition with medium-size missions to take better advantage of innovation and leveraged partnerships.
• Institutionalizing Sustained Science Continuity. Establish methods to prioritize and facilitate the continuation of observations deemed critical to monitoring societally important aspects of the planet, after initial scientific exploration has been accomplished.
• Enabling Untapped NASA-NOAA Synergies. Establish more effective means for NASA-NOAA partnership to jointly develop the next generation of weather instruments, accelerating NOAA’s integration of advanced operational capabilities.

Improved observations will enable exciting new science and applications by

• Initiating or Deploying More Than Eight New Priority Observations of Our Planet. Develop or launch missions and instruments to address new or extended priority observation areas that serve science and applications. Five are prescribed in the committee’s recommended program for NASA, and three are to be chosen from among seven candidate areas prioritized by the committee to form the basis of a new class of NASA competed medium-size missions. These new observation priorities will be complemented by an additional two new small missions and six new instruments to be selected through NASA’s existing Earth Venture program element, and two opportunities for sustained observations to be selected through the new Venture-Continuity strand of this program. The existing and planned POR will also be implemented as expected.

• Achieving Breakthroughs on Key Scientific Questions. Advance knowledge throughout portions of the survey’s 35 key science questions (Table S.1, above) that address critical unknowns about the Earth system and promise new societal applications and benefits.

Businesses and individuals will receive enhanced value from scientific advances and improved Earth information, such as

• Increased Benefits to Operational System End-Users. Enhanced processes and tools to leverage lost-cost commercial and international space-based observations will allow NOAA and USGS to have greater impact on the communities they serve.
• Accelerated Public Benefits of Science. Improved capacity for transitioning science to applications will make it possible to more quickly and effectively achieve the societal benefits of scientific exploration, generating applications more responsive to evolving societal needs.
• Development of Innovative Commercial Applications. New observations and data products enable innovative commercial applications that have the potential for substantial economic benefit to both developers and end users.

Building on the success and discoveries of the past several decades, this report’s balanced program provides a pathway to realizing remarkable scientific and societal benefits from space-based Earth observations. It ensures that the United States will continue to be a visionary leader and partner in Earth observation over the coming decade, inspiring the next generation of Earth science and applications innovation and the people who make that possible.

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