1 Agricultural technology, global land use and deforestation: A review

We review the complex relationship between the adoption of new agricultural technologies and land use change, explaining the multiple causal pathways of impact between adoption of yield-increasing technologies (such as an improved variety), land use change in general, and deforestation in particular. We present new estimates of the impact of crop germplasm improvement in the major mandate crops of the CGIAR between 1965 and 2004 on global land-use change, using the Global Trade Analysis Project Agro-ecological Zone model (GTAP-AEZ): a multi-commodity, multi-regional computable general equilibrium model linked to a global spatially-explicit database on land use. We find support for Norman Borlaug’s hypothesis that increases in cereal yields as a result of widespread adoption of Green Revolution technology have saved natural ecosystems from being converted to agriculture, although our results suggest that this effect is of a much smaller magnitude than Borlaug argued. We find that the total agricultural area in 2004 would have been between 17.9 and 26.7 million hectares larger in a counterfactual world which had not benefited from crop germplasm improvement since 1965. Of these counterfactual hectares, 12.0 to 17.7 millio