GM crops are not the answer to world hunger

Last week, chinadialogue columnist Taige Li explored whether genetic modification can increase crop yields. Emma Hockridge responds, and argues that oil-intensive biotechnology will not ease the global food crisis.

With soaring food prices around the world, there has been a renewed recent interest in whether the world can feed itself. This question is not a new one, and many organisations have been talking about the need to radically change our food and farming system to one which is more sustainable for many years.

The current industrial agricultural system, which has been in place for around 60 years, is wholly reliant on oil- and gas-intensive inputs such as fertilisers and pesticides.

The recent spate of media attention has given the pro-genetic modification (GM) lobby an opportunity to hijack the debate and attempt to persuade people that there is some mileage in this outdated debate. Although the GM industry has been promising huge benefits as a result of this technology for many years, the truth is that none of these claimed benefits have come to fruition. GM crops do not produce higher yields, use fewer pesticides, or do anything to assist people in developing countries.

It is obviously upsetting for the GM industry – and others who have a blind faith in the capacity of complex, high-tech solutions to solve every problem – to have their beliefs challenged by reality. This is what has happened to true believers in GM crops. Out in the fields of North America, while GM crops resistant to sprays or capable of killing insects have made life simpler for big farmers, they have not – according to the US department of agriculture – increased yields. In farmer’s fields in India, GM crops have not increased yields and have sometimes failed – with catastrophic consequences.

The recent International Assessment of Agricultural Knowledge, Science and Technology for Development (IAASTD) report, with input from hundreds of scientists from all over the world, recognises that the challenges farming now faces are those of the increasing scarcity and price of oil and the need to cut greenhouse-gas emissions from farming (primarily nitrous oxide) by 80% by 2050. As with energy production, the future of food production lies in systems which take nitrogen from the air to fertilise crops using energy from the Sun, as with organic farming, rather than burning up increasingly scarce oil and natural gas. Peer-reviewed scientific research continues to show that these sustainable farming systems will increase food production in developing counties, and will provide us with slightly more food than we currently produce. 

With specific regard to the question of yields, all major GM crop varieties in cultivation have produced yields that are lower than, or at best, equivalent to, those of non-GM varieties. The Soil Association has published a briefing on the latest available research on GM crop yields from the past ten years.
The research on GM crops as a whole shows that first-generation genetic modifications address production conditions (insect and weed control), and are in no way intended to increase the intrinsic yield capacity of the plant.

For example, an April 2006 report from the United States Department of Agriculture (USDA) states that “currently available GM crops do not increase the yield potential of a hybrid variety. […] In fact, yield may even decrease if the varieties used to carry the herbicide tolerant or insect-resistant genes are not the highest yielding cultivars”. The United Nations Food and Agriculture Organization’s 2004 report on agricultural biotechnology acknowledges that GM crops can have reduced yields. A 2003 report in Science by Matin Qaim and David Zilbermann – both strong supporters of GM crops – stated that: “in the United States and Argentina, average yield effects [of GM crops] are negligible and in some cases even slightly negative.”

For the three crops which are being produced using GM technology, the individual results are just as bleak. Studies from 1999 to 2007 consistently show Monsanto’s Roundup Ready (RR) GM soya to have 4% to 12% lower yields than conventional varieties. Yields of GM soybeans are especially low under drought conditions. Due to pleiotropic effects, when stems split under high temperatures and water stress, GM soybeans suffer 25% higher losses than conventional soybeans. The “yield drag” – or yield suppression – of RR soya is reflected in flat overall soybean yields from 1995 to 2003, the very years in which GM soya adoption went from 0% to 81% of US soybean acreage. By one estimate, stagnating soybean yields in the US cost soybean farmers US$1.28 billion in lost revenues from1995 to 2003.

Only maize shows a persistent trend of yield increase into the biotech era, but even here the rate of increase is no greater after than before biotech varieties were introduced. For example, a rigorous, independent study conducted in the US under controlled conditions demonstrated that Bt maize (see “Is GM the answer to the food crisis”, Taige Li) yields anywhere from 12% less to the same as very similar conventional varieties.

Despite claims of increased yield, Bt cotton has had no significant impact in real terms. Average cotton yields have increased fivefold since 1930, and staged an impressive surge from1980 to the early 1990s. Cotton yields then went flat, and continued to stagnate during the seven years of GM cotton’s rise to dominance. The steep yield and production increases in 2004 and 2005 were chiefly attributable to excellent weather conditions. Outbreaks of the secondary pests that are not killed by the Bt insecticide have rendered Bt cotton ineffective in China and are also becoming a problem in the American states of North Carolina and Georgia.

The debate over GM crops has now moved on: GM chemical companies claim they have the answer to world hunger while selling products which have never led to overall increases in production – and which have sometimes decreased yields or even led to crop failures. As oil becomes scarcer and more expensive, we need to move away from oil-dependent GM crops to producing food sustainably with renewable energy, as is the case with organic farming.


Emma Hockridge works for the policy department at the Soil Assocation

Homepage photo source: USDA