Projected Climate Change Impacts on Agricultural Management in Indiana

Studies exploring the impact of global climate change on agricultural production generally suggest a probable increase in crop productivity due to longer growing seasons and CO2 fertilization, with the potential for negative production impacts in warmer latitudes. Projected impacts at regional levels, particularly in the face of potential changes in precipitation timing and intensity, are not well quantified and highly uncertain. For this project, downscaled temperature and precipitation projections from the Hadley Centre Climate Model, version 3 for the highest and lowest Intergovernmental Panel on Climate Change emissions pathways were used in conjunction with the Variable Infiltration Capacity (VIC) macroscale hydrology model in a preliminary attempt to relate global climate change to the local level where agricultural management decisions are made. Specific benchmarks related to agricultural decision making, including average planting date and average harvest date, were first related to hydroclimatic variables for nine Indiana state climate divisions based on historic observations from the National Agricultural Statistics Service, Cooperative Observer weather stations and hydrology model simulations. Changes in these benchmarks, as well as number of growing degree days, days of soil moisture stress and the date of first and last soil frost, are explored for the decades of 2020-2029, 2030-2039 and 2040-2049, relative to the three decade period between 1961 and 1990. The relative influence of changes in temperature versus those in precipitation are also explored.