Climate change impacts on global agricultural land availability

Abstract

Climate change can affect both crop yield and the land area suitable for agriculture. Thisstudy provides a spatially explicit estimate of the impact of climate change onworldwide agricultural land availability, considering uncertainty in climate changeprojections and ambiguity with regard to land classification. Uncertainty in generalcirculation model (GCM) projections is addressed using data assembled fromthirteen GCMs and two representative emission scenarios (A1B and B1 employCO2-equivalent greenhouse gas concentrations of 850 and 600 ppmv, respectively; B1 representsa greener economy). Erroneous data and the uncertain nature of land classifications basedon multiple indices (i.e. soil properties, land slope, temperature, and humidity) are handledwith fuzzy logic modeling. It is found that the total global arable land area is likely todecrease by 0.8–1.7% under scenario A1B and increase by 2.0–4.4% under scenario B1.Regions characterized by relatively high latitudes such as Russia, China and the US mayexpect an increase of total arable land by 37–67%, 22–36% and 4–17%, respectively, whiletropical and sub-tropical regions may suffer different levels of lost arable land. For example,South America may lose 1–21% of its arable land area, Africa 1–18%, Europe 11–17%, andIndia 2–4%. When considering, in addition, land used for human settlements andnatural conservation, the net potential arable land may decrease even furtherworldwide by the end of the 21st century under both scenarios due to populationgrowth. Regionally, it is likely that both climate change and population growth willcause reductions in arable land in Africa, South America, India and Europe.However, in Russia, China and the US, significant arable land increases may still bepossible. Although the magnitudes of the projected changes vary by scenario,the increasing or decreasing trends in arable land area are regionally consistent.