How does the projected climate change impact on dry matter yields, greenhouse gas emissions and economics in Norwegian dairy farming systems

Abstract

Future climate projections showing increases in the air temperature and the number of rainydays in Norway will require changes in feed-base to adapt to climate change. A large number ofstudies have used single models to quantify the effects of management-related changes onproductivity, greenhouse gas (GHG) emissions and profitability. Here, we combined four models:BASGRA and CSM-CERES-Wheat, HolosNor and JORDMOD to estimate the impacts of projectedclimate conditions on grass and wheat dry matter (DM) yields, farm level GHG emissions andprofits. Simulations were carried out for baseline (1961-1990) and future (2046-2065) climateconditions projected based on two climate models and for production conditions with andwithout a milk quota. We compared four locations with different climate conditions for low, andmedian and high yielding years. The spring wheat grain DM yields simulated for the sameweather conditions within each climate projection varied between 2200 kg and 6800 kg DM perha. The GHG emissions intensities (kilogram carbon dioxide equivalent: kgCO2e emissions per kgfat and protein corrected milk: FPCM) varied between 0.82 kg and 1.25 kg CO2e per kg FPCM,with the lowest and highest emissions found in central Norway and south-east Norway,respectively. The farm profitability expressed by total national land rents varied from 1900 millionNorwegian krone (NOK) for median yields under baseline climate conditions up to 3900 millionNOK for median yields under future projected climate conditions. The projected future changein climate evaluated here decelerated the production of GHG emissions from dairy production inthe locations assessed due to higher milk yields per cow and partly to higher crop yields.