The Earth Science Enterprise has defined its Research Strategy around a hierarchy of scientific questions. At the highest level, the Enterprise is attempting to provide an answer to the one overarching question "How is the Earth changing and what are the consequences for life on Earth?" The magnitude and scope of this question are too large to allow a simple answer. The next tier of questions provides a structure constituting the conceptual approach ESE is taking to improve our knowledge of the Earth system.
1. How is the global Earth system changing?
Variability: Includes the internal variability of the coupled atmosphere-hydrosphere-biosphere system, with variability ranging from minutes to hours to days to all the way through seasonal, interannual, and longer timescales, as well as trends associated with human-induced changes, especially those occurring at decadal time scales (and longer). Emphasis is on global and large-scale regional variability.
- How are global precipitation, evaporation, and the cycling of water changing?
- How is the global ocean circulation varying on interannual, decadal, and longer time scales?
- How are global ecosystems changing?
- How is stratospheric ozone changing, as the abundance of ozone-destroying chemicals decreases and new substitutes increases?
- What changes are occurring in the mass of the Earth’s ice cover?
- What are the motions of the Earth and the Earth’s interior, and what information can be inferred about Earth's internal processes?
What are the primary forcings of the Earth system?
Forcing: Includes naturally-occurring forcing factors such as solar irradiance, volcanic eruptions, and land surface evolution, as well as human-induced changes such as increased atmospheric composition of radiatively and chemically active gases and particulates, changes in land use and cover, and changes in availability and quality of water.
- What trends in atmospheric constituents and solar radiation are driving global climate?
- What changes are occurring in global land cover and land use, and what are their causes?
- How is the Earth’s surface being transformed and how can such information be used to predict future changes?
How does the Earth system respond to natural and human-induced changes?
Response: Includes study of the processes that couple different components of the Earth system and give rise to feedback effects. Particular interest exists in the response of cloud distributions to changes in atmospheric circulation, the response of global ecosystems to changes in temperature, nutrients, and other factors, the atmospheric ozone response to precursors for both its production and destruction, and the response of polar ice to climate change.
- What are the effects of clouds and surface hydrologic processes on Earth’s climate?
- How do ecosystems respond to and affect global environmental change and the carbon cycle?
- How can climate variations induce changes in the global ocean circulation?
- How do stratospheric trace constituents respond to change in climate and atmospheric composition?
- How is global sea level affected by climate change?
- What are the effects of regional pollution on the global atmosphere, and the effects of global chemical and climate changes on regional air quality?
What are the consequences of change in the Earth system for human civilization?
Consequences: Includes study of local and regional impacts of changes that may be taking place on a global scale, as well as of the possible changes in the extremes of distributions of temperature and precipitation. Work on consequences is carried out through both the research and applications programs. ESE’s Applications program pursues demonstration projects applying Earth science, data and technology to areas of resource management, disaster management, community growth, and environmental quality.
- How are variations in local weather, precipitation and water resources related to global climate variation?
- What are the consequences of land cover and land use change for the sustainability of ecosystems and economic productivity?
- What are the consequences of climate and sea level changes and increased human activities on coastal regions?
How well can we predict future changes in the Earth system?
Prediction: Includes the improvements of environmental predictions, especially those that can accrue from innovative use of new data types provided by ESE. These address issues such as climate and weather on time scales from day-to-day, seasonal, interannual, and decadal, as well as composition of the atmosphere, including pollutants such as ozone and radiatively active gases such as carbon dioxide and methane.
- How can weather forecast duration and reliability be improved by new space-based observations, data assimilation, and modeling?
- How well can transient climate variations be understood and predicted?
- How well can long-term climatic trends be assessed or predicted?
- How well can future atmospheric chemical impacts on ozone and climate be predicted?
Science Priority Criteria
1. Scientific Return: The significance of the expected increase in our fundamental knowledge of some Earth system component or process, especially concerning the reduction of uncertainty, resolution of competing theories, or clear identification of the direction and magnitude of a feedback effect.
2. Benefit to Society: The extent to which the research outcome may be productively utilized on some relevant time scale for greater societal benefit (governmental, economic, individual).
3. Mandated Programs: Some NASA programs, such as the study of stratospheric ozone and continuity of the Landsat program, are required by law. Other activities may be given particular importance in the Federal budget at some point in time.
4. Appropriate for NASA: The extent to which an activity makes valuable use of the unique capabilities of NASA, and could not be done easily by other governmental or private entities. In many (but not all) cases, questions addressed by NASA take place at large regional to global scales, involve seasonal and longer response periods, and deal with larger impacts than are questions addressed by other agencies.
5. Partnership Opportunity: The extent to which needed work can be carried out in conjunction with partners, especially (but not exclusively) those of operational agencies in the US and abroad and partner space research agencies around the world.
6. Technology Readiness: The extent to which current technology enables a question to be productively addressed (and activities implemented). Note that where interest exists and technology does not, investments by ESE’s technology program can provide for the needed advances.
7. Program Balance: To assure overall progress, it is important that resources be distributed in a way that ensures scientific progress is not impeded by the lack of key information about some particular Earth system component or process. This is especially true for improvements in understanding of consequences and capability for prediction, which could be severely limited by lack of understanding of variability, forcing factors, and response mechanisms.
- Basic Research and Data Analysis:
- Systematic Measurements
- Exploratory Measurements
- Operational Precursor & Technology Demonstration Missions
- Data Management and Distribution
- Assessment
8. Cost: Required resources must be available if a particular question is to be addressed or a mission is to be implemented.
