GM back in the news

3 Sep 2015

It is a fair time since I had a rant about GM. I am not alone as the following quote from a recent opinion piece in The Times demonstrates:

‘The debate around genetically modified crops would almost certainly puzzle an alien. “I don’t get it,” he’d beep, arriving on his first tour of Earth. “You’ve found a way to boost crop yields and reduce your reliance on pesticides. Repeated, peer-reviewed scientific studies have shown there is no downside. It could be the answer to a pending crisis of global hunger, with no ill-effect. Yet it still makes lots of people very angry, and many governments avoid it in horror. Why?’

It is very easy to answer that question. There are too many organisations who have pinned their reputation and, in some cases, their finances on being against the technology. It has also become an ideological struggle against ‘multi-nationals’. Hence, the same old scares are repeated and new issues are exploited as being evidence against the technology. A prime example is the reducing numbers of the monarch butterfly in the US. These iconic butterflies migrate in the autumn from southern Canada and northern US to a specific area in central Mexico in huge and spectacular clouds.

Monarch butterflyThe monarch butterfly first entered the GM debate when it was found that they died when contained in chambers heavily laced with pollen from Bt maize modified to control corn-borers. This is no surprise; if you continually expose an insect to very high levels of something that is known to kill it, it will die. The key issue is in real life would the monarch butterfly be exposed to sufficient amounts of this pollen to affect its health? The judgement of the experts is that it would not.

Despite this, there have been recent headlines that GM Bt and glyphosate tolerant maize is responsible for the recorded decline in the Monarch butterfly. However, looking behind the headlines is a more nuanced explanation. Monarch butterflies feed exclusively on native milkweeds (Asclepias species) and cannot survive without them. Native milkweeds are perennials that flourish in semi-natural areas such as road sides, edges of fields and also in uncropped land. The plant declined by 58% in the plains states from 1999 to 2010. Monarch populations dropped by 81% in the same period.

It now seems that the major factor in the decline of milkweed is that more land is now cropped with maize in order to supply the ethanol plants. Nearly 4.5 million hectares have been taken out of the Conservation Reserve Programme, much of it going into maize. It has to be acknowledged that glyphosate tolerance enables a higher level of control of native milkweeds in maize but the shift into maize and out of something akin to set-aside has been a major factor. This is an unintentional consequence of promoting biofuels.

Another reason for the fall in the population of the Monarch butterfly may be illegal logging in Mexico where it overwinters on trees. The logging was almost halted at one stage but there are recent reports that it has recommenced.

Taking the populist decision to ban GM, as the Scottish Government has done, is an easy way out for European governments. They are really abdicating their responsibility to lead the debate rather than just blindly follow public prejudice that has been stoked up by misleading and misinterpreted information. It seems that getting a better balance between crop production and biodiversity is ever more challenging and it is my view that GM technology can play a role in improving the chances of getting it right.