The overall objective of this Statement of Need (SON) was to resolve significant uncertainties of carbon estimates in natural systems found on Department of Defense (DoD) installations and ranges. Enhanced measurement and modeling capabilities of carbon pools, fluxes, and forcing factors driving variability were required to quantify uncertainty in current estimates, reduce future uncertainties associated with DoD ecosystems, and support better climate-informed management decision making through managed disturbances under climate extremes. Specific objectives included scientific advancements, studies, new strategies, and innovations that accomplish the following:

• Improve the accuracy of estimates of carbon pools and fluxes, and of the effects of driving processes of carbon dynamics (including military activities) in ecosystems found on DoD lands.
• Characterize and reduce the uncertainty associated with monitoring efforts used to estimate carbon on DoD installations or adjacent sites.
• Characterize and reduce the uncertainty associated with ecophysiological processes that directly impact carbon pools and fluxes that are not well represented in existing ecosystem process models.
• Address the size and distribution of uncertainties in carbon and climate models, partition and constraint uncertainties, and develop outputs to effectively communicate those uncertainties to DoD policy makers and managers of natural infrastructure.
• For identified uncertainties, develop new approaches to create datasets or improve methods currently used in national or regional estimates and reporting, such as those that supply the Inventory of US Greenhouse Gas Emissions and Sinks and standard IPCC emission factors which could be applicable for DoD lands. 

Proposals addressed ecosystems relevant to the DoD, and address processes relevant to improving uncertainty in carbon estimates. Ecosystems of greatest interest included, but were not limited to, Arctic regions, southeast wetlands, peatlands, southeastern conifer forests, coastal ecosystems (salt marshes and mangrove forests), coral reefs, Pacific Island forests, and semi-arid grasslands. Relevant processes included, but were not limited to, permafrost hydrology, wildland fire, lateral fluxes of carbon, silvicultural activities, and cycling of soil organic and inorganic carbon. Proposals leveraged existing monitoring networks (e.g., Ameriflux, NEON), where possible, and used standardized metadata, sampling approaches, and established frameworks for any new data acquisition.

Carbon cycling of ecosystems is a critical process that sustains the mission. With increasing exposure of DoD installations to natural hazards and weather extremes, understanding how fast carbon pools respond to these events, and how management actions and the military mission activities drive carbon dynamics, will help determine long-term resilience of the DoD’s 27 million acres of natural infrastructure. Addressing the SON objectives described above will facilitate the DoD’s development of actionable strategies, frameworks, tools, and datasets for forecasting and projecting future greenhouse gas (GHG) emission reduction and biosequestration enhancement options across all relevant time scales to meet the need to integrate climate change mitigation, adaptation, and resilience into ecosystem and land-use decision-making processes.

GHG and carbon management in natural and managed systems is part of the DoD’s climate assessment priority across its 27 million acres. The DoD requires the ability to measure, monitor, model, and otherwise estimate fluxes and the net balance of carbon and GHG in natural systems in the context of both military activities as well as the resource management approaches designed to sustain productivity, avoid loss from carbon pools, and reduce GHG emissions. A major challenge is understanding the uncertainties in tools, models, data products, and estimation methods which, in some cases, remain high and unconstrained. Ecosystem and climate-informed decision making can live side by side with uncertainties in tools and estimates, but only if the size and distribution (such as sources) of these uncertainties are transparently communicated and continuously improved. Uncertainties in carbon and GHG tools and data products are the result of multiple and interacting factors, such as climate change, acute and chronic disturbances, atmospheric CO₂ concentrations, coverage of instrumented and field-collected measurements, standardized data products, data scaling over space and time, management actions, natural disturbances, weather extremes, as well as model structure, parameterization, and calibration processes. 

The cost and time to meet the requirements of this SON are at the discretion of the proposer. Proposers submitting a Standard or Limited Scope Proposal must provide the rationale for the proposed scale. The two options are as follows: 

Standard Proposals: These proposals describe a complete research effort. The proposer should incorporate the appropriate time, schedule, and cost requirements to accomplish the scope of work proposed. SERDP projects normally run from two to five years in length and vary considerably in cost consistent with the scope of the effort. It is expected that most proposals will fall into this category. 

Limited Scope Proposals: Proposers with innovative approaches to the SON that entail high technical risk or have minimal supporting data may submit a Limited Scope Proposal for funding up to $250,000 and approximately one year in duration. Such proposals may be eligible for follow-on funding if they result in a successful initial project. The objective of these proposals should be to acquire the data necessary to demonstrate proof-of-concept or reduction of risk that will lead to development of a future Standard Proposal. Proposers should submit Limited Scope Proposals in accordance with the SERDP Core Solicitation instructions and deadlines.