Farm simulation can help dairy production systems adapt to climate change

Climate change may affect many aspects of dairy production, including growing season length, crop growth processes, harvest timing and losses, heat stress on cattle, nutrient emissions and losses, and ultimately farm profitability. To assess the sensitivity of dairy farms to climate change, climate projections for higher and lower emission scenarios were downscaled from the National Center for Atmospheric Research Community Climate System Model version 4 (CCSM4) by using the Asynchronous Regional Regression Model. The Integrated Farm System Model (IFSM) was then used to simulate representative dairy farms over 25-yr periods by using recent historical climate and projected mid and end-of-century climate data. Base farms reflected current production practices with recent climate in southern Pennsylvania, northern New York, central Wisconsin, southern Idaho, central California, and central Texas. We explored management changes to adapt the farms to future climate by modifying crop varieties and planting and harvest dates, and for the Pennsylvania, Wisconsin, and Idaho locations; double cropping of small-grain silage and corn silage was included in future climate simulations. Responses to projected climate change varied across the six locations, but common trends were found. For most locations, projected climate improved forage production but decreased corn grain production. Higher temperatures and changes in precipitation patterns increased gaseous emissions and nutrient losses from farms. For most scenarios, farm profitability was maintained in projected climate through adaptations in management. This simulation study illustrates that climate and farm simulation models can provide valuable information for planning and adapting our dairy farms to changing climate.