There's been a lot of 'noise' recently about how genetically engineered (GE) crops can help "feed the world", and that they can help agriculture in a climate-affected world. But are these promises real or just hype?
If we look at recent studies, they actually highlight the failures of GE technology to deliver on its promises, and the mounting evidence that agricultural productivity is better served by a focus on ecological agriculture. For instance, the latest study (Heinemann et al. 2013) by the University of Canterbury, New Zealand found that "Despite the claims that GE might be needed to feed the world, we found no yield benefit when the United States was compared to West Europe, other economically developed countries of the same latitude which do not grow GE crops". This is not altogether surprising as there simply are no GE crops designed to increase yield. They do not exist.
The majority of currently existing GE crops (for example Monsanto's "Roundup Ready" GE soya) are herbicide tolerant, which allow herbicides to be sprayed liberally, killing all plants apart from the GE crop. This is not good for biodiversity because it affects animals such as birds and insects by reducing the abundance of plants that they feed on. This might also include bees, adding pressure to already declining populations. The remainder of GE crops are mostly insect resistant and produce their own pesticide (for example GE Bt corn). These are also not good for biodiversity as these GE crops can kill other insects such as butterflies. Problems of insect resistance and other, secondary insect pests, mean that farmers have to continue spraying pesticides with GE Bt crops. With GE crops, farmers are still on the pesticide treadmill.
The reality is that the promised "beneficial" GE crops are stuck at the development stage in the lab. The reason is that scientists are finding that the traits we need to help crops to cope with climate change (e.g. heat tolerance) or increased nutrition (e.g. enhanced vitamins) are actually quite complex and controlled by several genes. Genetic engineering is a crude technology and is no match the tightly controlled network regulating gene expression in cells. For example, "Golden" rice, a GE rice variety, is still in development after 20 years, largely because of the complexity of the genetic engineering.
Meanwhile, advances in conventional breeding mean that several of the crops promised by genetic engineering are already in farmer's fields. For example, both flood and drought tolerant rice are already in farmer's fields and drought resistant maize is available in many parts of Africa where it's needed. Nutrient enhanced crops also exist already – without using genetic engineering but a more sustainable solution is to improve access to a healthy and diverse diet.
It's clear that GE crops are not capable of producing the crops that farmers and consumers need, whilst the quiet revolution in conventional breeding techniques is already producing these crops.
GE crops are stuck with two simple traits: herbicide tolerance and insect resistance. These do not help to "feed the world", but pose threats to human and animal health, as well as biodiversity.
So the answer to the original question is no. GE crops are not needed to feed the world but are just hype.
Janet Cotter is a Senior Scientist at the Greenpeace International Science Unit.
 Heinemann, JA et al. 2013. Sustainability and innovation in staple crop production in the US Midwest, International Journal of Agricultural Sustainability: DOI:10.1080/14735903.2013.806408;
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