Graham Brookes and Peter Barfoot
PG Economics Ltd., Dorchester, UK

Genetically modified (GM) crops have been grown commercially on a substantial scale for eleven years. This paper updates the assessment of the impact this technology is having on global agriculture from both economic and environmental perspectives. It examines specific global economic impacts on farm income and environmental impacts associated with pesticide usage and greenhouse gas (GHG) emissions for each of the countries where GM crops have been grown since 1996. The analysis shows that there have been substantial net economic benefits at the farm level amounting to $6.94 billion in 2006 and $33.8 billion for the eleven-year period (in nominal terms). The technology has reduced pesticide spraying by 286 million kg and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops by 15.4%. GM technology has also significantly reduced the release of GHG emissions from this cropping area, which, in 2006, was equivalent to removing 6.56 million cars from the roads.
Key words: Yield, cost, income, environmental impact quotient, carbon sequestration, GM crops.