The Effect of Climate Change on Milk Yield in New Zealand: A Case Study of Fonterra

Climate change affects milk yield, which may have a profound impact on the dairy industry. Taking Fonterra as an example, this study analyses the climate data of 99 consecutive months from June 2012 to August 2020 and the corresponding monthly milk yield data of North Island and South Island. The results show that the monthly milk yield correlates with the monthly mean temperature, the monthly extreme maximum temperature, the monthly extreme minimum temperature, the monthly mean relative humidity, and the monthly mean temperature and humidity index (THI). In addition, with the increase of annual mean temperature in New Zealand, the annual milk yield of North Island decreases with the increase of temperature. Fonterra needs to take measures to mitigate the negative impact of climate warming on milk yield. However, in the recent nine years, South Island’s annual milk yield increases with annual mean temperature. Furthermore, regression equations with climate factors as independent variables and monthly milk yield as dependent variables are established for North Island and South Island. In North Island, the monthly milk yield changed periodically with time. The findings of the study show that the annual milk yield will decrease with the increase of temperature due to global warming in North Island. However, South Island needs to deal with the negative impact of high temperature on milk yield in summer. Therefore, Fonterra needs to take immediate measures to deal with the negative impact of climate change.