Support for EPA's Activities - Examining Sectoral Impacts of Climate Change and Linking Observations and Projections

DESCRIPTION: Columbia University will support the ICF agriculture impact review, providing insights from the Agricultural Model Intercomparison and Improvement Project (AgMIP) community (Rosenzweig et al., 2013; Ruane et al., 2017), including recent development and intercomparisons for crop species models, regional and global integrated assessment, and impact analyses.

Columbia University will simulate yield under current and future climates over the Contiguous United States for 6 crops utilizing process-based crop models. The LPJmL model will be utilized on a 1/4-degree grid for maize, winter wheat, spring wheat, soy, pasture/grasslands, and sorghum. These crops encompass the majority of farm area in the US, and also allow for estimates of livestock productivity given their prominence as feed and fodder. We will also explore the possibility to compare results with pDSSAT for select crops and potentially add species (e.g., cotton, peanut, canola) depending on resources. Simulations are built upon process understanding and calibration of biophysical growth, with local differences owing to genetics (e.g., cultivar selection), environment (soils and climate conditions), and management drawn from USDA and local reporting (e.g., planting dates, irrigation, fertilizer).

Columbia University will survey recent literature and AgMIP activity outputs to identify the potential for yield effects to affect future agricultural production that are not well-captured in process-based models. These include pests, diseases, ozone, and responses to excess moisture, such as water logging and river basin floods. These effects will be represented as bounding damage factors that may be applied to simulated outputs at various degrees, leading to further benefits/losses that may potentially be offset under adaptation scenarios. Results will draw upon new activities within the AgMIP Pests and Diseases Model Intercomparison Project (PeDiMIP) and the AgMIP Air Pollution Activity, among others. While it is not practical to perform a detailed analysis of all potential hazards, pests, diseases, and their interactions with specific regional farming systems, analyses will focus on evaluating the scale of these risks within the context of regional economic projections.

Columbia University will provide crop model outputs and additional yield effect factors as inputs for national economic modeling of agricultural impacts (to be conducted by other project partners). Additional insights may be drawn from AgMIP activities around global economic modeling, coordinated global and regional assessments (CGRA; e.g., Ruane et al., 2018), and the Global Gridded Crop Model Intercomparison (GGCMI; Müller et al., 2017).

Columbia University will lead the analyses of crop yield projections, and help interpret the ramifications of yield changes for national economic responses, the monetization of impacts, and the potential for prioritized adaptation strategies. Development of the primary paper will be led by other project partners, although it is possible that additional papers may be written to further assess results.