Forecasting material and economic flows in the global production chain for silicon

Material and economic flows in a global production chain are analyzed in order to identify shifts in economic structure relevant to environmental issues. Results suggest that the economic and environmental weight of high-tech manufacturing and specialized material sectors will increase significantly relative to extractive and primary commodity sectors, perhaps reaching a similar environmental scale within a few decades. Though further study is needed, the forecasts suggest that a reprioritization of analysis and policy to address these new industries is in order. These results are based on a case study of the global production chain for high-purity silicon and its use in semiconductors, solar cells and optical fiber from primary materials. Forecasts for future material/economic flows are carried out based on the identification of time scales that reveal stable long-term trends. Assuming constant growth over 7–10 year averages reproduces thirty years of historical growth of three global sectors to around 1–2% accuracy. This suggests the constant growth model can be used to forecast with a relatively high degree of confidence.