Does climate change affect crops differently? New evidence from Nigeria

Climate change affects crops differently across different parts of the world. However, there is limited evidence on the impacts of climate change on several crops using models that simultaneously incorporate other production factors (such as credit, land and fertilizer) and account for both the short-run and long-run relationships of climate and factors of production on the output of different crops. We therefore investigated the impacts of climate change on six major crops in Nigeria using time-series data for a period of 39 years. We used the Augmented Dickey–Fuller and Phillips–Perron tests to determine the stationarity of the data and applied the Autoregressive Distributed Lag (ARDL) regression to model the impacts of climate change, factors of production on the outputs of the crops. All the six ARDL models were structurally stable and they exhibited both short-run and long-run relationships between climate change, production factors and outputs of the crops. Specifically, land exhibited long-run positive relationships with the outputs of all the crops except for millet. Temperature had a negative impact on crop yam, cassava, millet, rice and sorghum outputs in the long run while rainfall significantly increased rice and maize production but insignificantly reduced yam, cassava, millet, and sorghum production in the long run. Credit significantly increased cassava, maize, and rice in the long run, while fertilizers showed mixed impacts on yam, cassava, rice and sorghum production in the long run. We recommended policies and programs that would increase access to credit to farmers, encourage nutrient budgeting and precision use of fertilizer, and promote uptake of climate smart agriculture through research on crop improvement by breeding crop varieties that would be resilient to climate shocks.