by Caroline Vurlumis
Anthropogenic climate change may lead to more extreme weather events and will impact human health and the economy. One of the most important effects of climate change however is its impact on agriculture and the human population. Using ecological niche modeling (ENM), a technique to relate species presence to environmental factors, Beck (2013) sought to model suitability of agriculture in different regions based on soil conditions and climate. He applied this general and simple model for agriculture across the Old World (defined as Asia, Africa and Europe) and the Australia/Pacific region to create model scenarios of agriculture for the year 2050 and determined which countries would win or lose from climate change in the agricultural sector; different regions vary considerably in agricultural suitability which cannot simply be determined by a country’s wealth. Beck’s model predicted that parts of Europe, Africa and southern and eastern Asia will have a negative impact while north-eastern Europe and the Tibetan plateau will benefit.
Beck started his modeling by first obtaining 290 records of agriculture presence worldwide. These data were assembled from ‘traditional’ plants (excluding cash crops, pastures, greenhouses and high-tech practices) and used to make a probability model of agriculture occurrence from current climate and soil conditions across the Old World. The sites chosen contained staple crops such as maize, rice, wheat and rye. Current data taken from http://www.worldclim.org and data from the Food and Agriculture Organization (bioclimatic and soil types) were applied in Beck’s ENM. The maximum entropy method was applied to determine the best data set for accessing the probability of future agriculture change. In addition, the author used two global circulation scenarios: the A2a (economic interests followed, fast population growth) and B2a (social and environmental interests followed, slower population growth), which represent a negative and a positive scenario of climate change and economic growth patterns. From these models and data the author predicted agricultural suitability possibilities in 2050.
Beck’s models predicting suitability of agriculture presented in the global circulation models A2a and B2a both foresaw a decrease. There was variation but overall the loss was high. There were barely any losses in rye growing regions, intermediate losses for wheat and maize, and larger losses in tropical plant areas. East Europe on average was predicted to benefit from climate change while West Africa was predicted to suffer. Other regions, with what is currently judged to be agriculturally poor land including Western Europe, will benefit from climate change. In general, results reflected similar projections from earlier studies showing slight decreases for agriculture worldwide and large variation in results.
Since ENM is a simple approach that uses less data on productivity and agricultural practices than previous models, the author acknowledges the potential errors that could have been involved, including input data error, technical issues, and misinterpretation. This model assumes local variation of agricultural practices in addition to local adaptation. Nevertheless, the data represented by this ENM model suggest that both rich and poor countries will suffer loses in agricultural suitability and this model should be used in accordance with other models to predict future trends.
Beck, J., 2013. Predicting climate change effects on agriculture from ecological niche modeling: who profits, who loses? Climatic change 116, 177-189. Full text at: http://bit.ly/ZZVlTs