On October 22, Timothy Thomas presented “Aflatoxins and Climate Change: Preliminary Results from a New Biophysical Model for Groundnuts and Selected FTF Countries” at USAID. The presentation focused on groundnut production in Burkina Faso and Niger. The main results are presented in Table 1, which shows the normal aflatoxin concentration at the national level with and without climate change. Results vary by climate model: With the GFDL climate model, aflatoxin contamination is projected to increase, while contamination might virtually disappear with the MIROC model.
Table 1. Preliminary Results Showing Probability of Dangerous Aflaxtoxin Concentrations (> 20 ppb) in Groundnuts
% of years and area that contamination was > 20 ppb | ||||||
No climate change | 2050 | |||||
Country | GFDL | HadGEM | IPSL | MIROC | NoRESM | |
Burkina Faso | 15.3% | 27.5% | 13.0% | 14.1% | 0.9% | 11.7% |
Niger | 18.2% | 23.0% | 12.0% | 8.6% | 0.3% | 8.5% |
Source: Authors.
Figure 1 shows changes in concentration for the same two climate models that also show the most extreme results: GFDL and MIROC. For both models, aflatoxin concentrations fall in the northern part of the groundnut growing areas, but they rise in the southern and western parts in the GFDL climate model while they fall in the MIROC model.
Figure 1. Change in the Share of Years with Aflatoxin Concentrations above 20ppb, 2000-2050
Source: Authors.
This is due to the fact that changes in climate are vastly different between the two models. Figure 2, shows changes in precipitation, and we see that the GFDL model projects the region getting drier while the MIROC model projects the region getting wetter. Drought or dry conditions during the last four weeks before harvest have been found to vastly increase aflatoxin concentrations.
Figure 2. Changes in precipitation from June to August, 2000-2050
Source: Authors, based on WorldClim 1.4 (Hijmans et al. 2005).
While the work is still preliminary, it is hoped that with continued development and testing, the model would not only be useful for examining the effects of climate change on afltatoxin concentrations, but might also be used as an aflatoxin early warning system or hotspot identifier.
References
Hijmans, R.J., S.E. Cameron, J.L. Parra, P.G. Jones and A. Jarvis, 2005. Very high resolution interpolated climate surfaces for global land areas. International Journal of Climatology 25: 1965-1978.