Foreword

This brief is intended for use by a wide range of people with interests in agriculture and the environment.  As a summary of the key findings relating to the impact of biotech crops (1996-2007), it focuses on the environmental effects associated with pesticide usage and greenhouse gas (GHG) emissions, as detailed in ‘Global impact of biotech crops: socio-economic and environmental effects 1996-2007’[1], by Graham Brookes & Peter Barfoot[2].  The food security analysis presented in this document is derived from data contained in the full report. 

Environmental benefits

Pesticide reductions

Since 1997, the use of pesticides on the biotech crop area has been reduced by 359 million kg of active ingredient, an 8.8% reduction.  This is equivalent to one and a quarter times the total volume of pesticide active ingredient applied to arable crops in the EU (27) in a year.   

Whilst changes in the volume of pesticides applied to crops can be a useful indicator of environmental impact, it is an imperfect measure because it does not account for differences in the specific pest control programmes used in biotech and conventional cropping systems.  Using a more robust and comprehensive measure of the environmental impact associated with pesticide use, the environmental impact quotient (EIQ[3]), this measure shows that the environmental impact associated with herbicide and insecticide use on the area planted to biotech crops between 1996 and 2007 fell by 17.2% (Table 1).   

In both absolute and per hectare usage terms, the largest environmental gain has been associated with the adoption of biotech IR cotton.  Since 1996, farmers have used 147.6 million kg less insecticide in biotech IR cotton crops (a 23% reduction), and this has reduced the associated environmental impact of insecticide use on this crop area by 27.8%.  

Important environmental gains have arisen from the use of biotech HT soybeans, reflecting the large share of global soybean plantings accounted for by biotech soybeans (Table 1).  The volume of herbicides used in biotech soybean crops decreased by 73 million kg (1996-2007), a 4.6% reduction, and, the overall environmental impact associated with herbicide use on these crops decreased by 20.9% (relative to the volume that would have probably been used if this cropping area had been planted to conventional soybeans).  Important environmental gains have also arisen in the maize and canola sectors (Table 1).   

Table  1: Global impact of herbicide and insecticide use changes from biotech crops 1996-2007

In terms of the division of the environmental benefits associated with less insecticide and herbicide use, over half of the environmental benefits (1996-2007) have been in developing countries (52%).  The vast majority of these environmental gains have been from the use of biotech IR cotton and HT soybeans. 

Greenhouse gas emission (GHG) cuts

Biotech crops have also delivered significant savings in greenhouse gas emissions.  In 2007, the 111 million hectares of biotech crops facilitated a 14.2 billion kg reduction in carbon dioxide emissions, equivalent to removing 6.3 million cars from the roads for a year (equal to 24% of all registered cars in the UK off the roads for a year (Table 2)).   

Table 2: Impact of biotech crops on carbon emissions 2007

The GHG emission reductions derive from two principle sources: 

·         Reduced fuel use from less frequent herbicide or insecticide applications and a reduction in the energy use in soil cultivation.  The fuel savings associated with making fewer spray runs (relative to conventional crops) and the switch to conservation, reduced and no-till farming systems, have resulted in permanent savings in carbon dioxide emissions.  In 2007, this amounted to about 1,144 million kg (arising from reduced fuel use of 416 million litres: table 2).  Over the period 1996 to 2007 the cumulative permanent reduction from fuel use is estimated at 7,090 million kg of carbon dioxide (arising from reduced fuel use of 2,578 million litres)

·         the use of ‘no-till’ and ‘reduced-till’[4] farming systems.  These production systems have increased significantly with the adoption of biotech HT crops because the HT technology has improved growers ability to control competing weeds, reducing the need to rely on soil cultivation and seed-bed preparation as means to getting good levels of weed control.  As a result, tractor fuel use for tillage is reduced, soil quality is enhanced and levels of soil erosion cut.  In turn, more carbon remains in the soil and this leads to lower GHG emissions.  Based on savings arising from the rapid adoption of no till/reduced tillage farming systems in North and South America, an extra 3,570 million kg of soil carbon is estimated to have been sequestered in 2007 (equivalent to 13,103 million kg of carbon dioxide that has not been released into the global atmosphere).  Cumulatively the amount of carbon sequestered is probably higher due to year-on-year benefits to soil quality.  However, due to the lack of data on the crop area in continuous no-till systems it is not possible to confidently estimate cumulative soil sequestration gains.

Other impacts

Farm income impacts

GM technology has had a very positive impact on farm income derived from a combination of enhanced productivity and efficiency gains (Figure 1).  Between 1996 and 2007, farm incomes increased by $44.1 billion.  In 2007, the direct global farm income benefit was $10.1 billion, equivalent to adding 4.4% to the value of global production of the four main crops of soybeans, corn, cotton and canola.

Figure  1: Global farm income benefits from growing biotech crops 1996-2007 ($ millions)

Note: Others = virus resistant papaya and squash

Improving economic well being and food security

The extra farm income from growing biotech crops, when spent on goods and services, has had a positive multiplying effect on local, regional and national economies.  In developing countries, the additional income has enabled more farmers to consistently meet their food subsistence needs and to improve the standards of living of their households.  In India and the Philippines, where farmers use biotech IR cotton and corn respectively, their household incomes have typically increased by over a third.      

Biotech crops have also, since 1996, added important volumes to global production of corn, cotton, canola and soybeans (Table 3). 

 Table 3: Additional crop production arising from positive yield/production effects of biotech crops

This additional production arising from biotech crops (1996-2007) has also contributed enough energy (in kcal terms) to feed about 402 million people for a year (additional production in 2007 contributed enough energy to feed 88 million, similar to the annual requirement of the population of the Philippines: see appendix for assumptions and calculations).  Important contributions to meeting the protein and fat requirements of considerable numbers of people have also arisen.  

Appendix

Food security assumptions and calculations 

Human food requirements per day (recommended daily allowances)

Source: FAO

Crop key nutrition composition (per kg of edible material)

Source: USDA - Nutritional database for standard reference www.ars.usda.gov   

Main constituents of oilseeds (source: Soya & Oilseed Bluebook) 

·         Soybeans: 79.2 per cent meal, 17.8 per cent, oil, 3 per cent waste

·         Canola: 59 per cent meal, 38 per cent oil, 3 per cent waste

·         Cottonseed: 44.9 per cent meal, 16.2 per cent oil, 8.2 per cent lintners, 26.7 per cent hulls, 4.1 per cent waste 

Assumption on corn utilization – 99 per cent usable 

Assumptions for uses of crops %

Source: derived from USDA ERS Feed Grains database www.ers.usda.gov/data/feedgrains 

Use of corn and oilseeds in meat production assumptions 

The following simplifying assumptions were used: 

·         As most corn and oilseeds at the global level are used in pig and poultry rations, all usage is assumed to be in these two sectors;

·         Corn: 2.6 kg corn produces 1 kg of poultry meat at the consumer level, 6.5 kg of corn produces 1 kg of pig meat at the consumer level (source: USDA ERS – www.ers.usda/amberwaves/february2008/features/cornprices.htm.  Readers should note these are conservative estimates;

·         Feed conversion ratios of 1.8 kg feed produces 1 kg of chicken (live weight) and 3 kg of feed produces 1kg of pig (live weight) – typical feed conversion rates in developed countries for poultry are 1.7/1.75:1 and for pig meat are 2.5/2.8:1, hence the conversion rates used are conservative;

·         Conversion of live weight to meat eaten by a consumer – for poultry assumes 50 per cent of live weight converted to meat and for pig meat assumes 35 per cent conversion; 

·         corn constitutes 70 per cent of a typical poultry feed ration and 75 per cent of a typical pig ration;

·         meals (from soy, canola and cottonseed) are assumed to supply the main part of the protein requirement in the feed ration with incorporation rates of 25 per cent in poultry feed and 20 per cent in pig feed;

·         Based on the above assumptions, it takes 0.93 kg of meal to produce 1 kg of poultry meat (at the consumer level) and 1.73 kg of meal to produce 1kg of pig meat (at the consumer level).