• Question: I have many concerns about GM but the greatest are: 1. The potential effects on ecosystems by way of altering the genetic makeup (carefully engineered by nature) of other species; I think you have to some extent addressed this already; and 2. The prospect of more, and more extensive, monoculture and the resulting damage to ecosystems/biodiversity. We have already lost much of our biodiversity due to the move away from mixed farming and towards monoculure. As I see it, any increase in the use of GM will exacerbate this. Would the epxerts care to comment. Thank you.

    Asked by alisont to Andy, Cathie, Jules, Les, Ricarda on 29 Jun 2012.
    • Photo: Les Firbank

      Les Firbank answered on 29 Jun 2012:


      This is my area of expertise …
      Point (1) is not that big a deal in practice, and can be managed by making sure that we have tight rules about allowing GM plants to be grown outdoors
      Point (2) is a huge issue, also because it’s not clear that monocultures are worse for the environment that mixed farming. This is because monocultures tend to be more productive in practice, and so it is argued that more monocultures in one place means more room for wildlife in another. Have a look at the first answers about feeding the world.
      I am really worried that during the 21st century we will struggle to feed the world and keep our natural habitats, monocultures, mixed farming, GM or not.

    • Photo: Julian Little

      Julian Little answered on 3 Jul 2012:


      Hi Alison, that’s two very perceptive questions. Not easy ones but I’ll have a go at answering them. You mentioned the idea of the genetic make-up of a plant as being ‘carefully engineered by nature’, maybe analogous to ‘intelligent design’? However, the genetic make-up of a plant is in continuous flux from one generation to another, with plants cross-pollinating others to produce sometimes quite dissimilar off-spring. If they didn’t, plants (and animals) couldn’t evolve.

      Hence apple growers have to be quite careful about which apple trees pollinate their trees – if they didn’t, they would risk producing apples that didn’t taste or appear anything like what they were looking for. They do this by planting appropriate ‘male’ pollinating trees of a specific type in and around the orchard thus reducing the chances of pollen from afar affecting their precious crop.

      So back to GM. With this technology, genes imparting a particular attribute are added to the plant’s genome. The GM plant differs only from its GM counterpart only in that particular attribute – in fact, that is one of the tests you have to do for regulatory approval of the final GM crop, ie you have to demonstrate that it is ‘substantially equivalent’ to its non-GM counterpart.

      On to question 2, that GM will increase monoculture. Thinking about this one, I was reminded that there are 160 million or so hectares of GM crops grown every year and this is increasing by about 10% per year. There are also over 16 million farmers growing these crops and this has gone up by about 1 million each year for the last few years. Quick calculation and I make that a bit less than 10 hectares/ farmer, and taking into account that some farmers in the US and Argentina are growing 10000 hectares, most farmers must be growing significantly less than 10 hectares. Not exactly a monoculture then… By the way, should have pointed out that almost 50% of the area of GM crops grown last year were grown by resource-poor farmers in less developed countries. They are a long way off monoculture, and yet find that GM works for them (www.ISAAA.org).

    • Photo: Andy Stirling

      Andy Stirling answered on 4 Jul 2012:


      Thanks Alsiont. As with other questions, the issues here are complex and not in any simple or direct way leaning exclusively ‘for’ or ‘against’ GM. But the implications are not as one-sided as Les and Julian suggest in their answers.

      Yes, there are, as Les says, possible trade-offs. Wildlife and biodiversity in some areas may benefit in some ways from there being greater room for ecologies that are less disturbed by concentrating agricultural production on less land.

      The degree to which GM can help drive such concentration by increasing productivity is contested (including in this present debate) – both in its scale and its wider implications. But, to the extent this is true, then GM might potentially offer some help to biodiversity in these particular ways and contexts.

      But in other places and ways, there are also very important benefits for wildlife and biodiversity from avoiding such concentration of agriculture. In some areas – like many parts of the UK – farmed in the right way, agricultural land can be an important reservoir of biodiversity. So if GM does, as it is claimed, concentrate production more intensively around monocultures in these areas, then it will – as Alisont says – likely have a negative effect.

      But if – like the earlier responses – we leave the issues at that, then we miss the potentially crucial social, economic and technological dynamics. It is far from clear that concentrating agricultural production on some land, will – as claimed by Les and Julian – make it easier to support biodiversity and wildlife on other land. This ignores the complexities and potential positive feedbacks in the ways social and industrial systems evolve.

      In particular, it ignores ‘rebound effects’. For instance, it is often assumed that introducing energy saving (more ‘intensive’ use) will reduce overall energy consumption to a degree that directly reflects the amount of energy saved. But because society is complex, it often doesn’t work like this.

      In short, people often consume an energy saving as a performance gain. For example, they are encouraged by the availability of a higher efficiency fridge, to buy a bigger fridge than they would otherwise have done. Or they use the resources saved by the efficiency in order to undertake another activity that is potentially even more problematic. For instance, people may use money saved by energy efficient daily transport to go on more recreational air travel.

      This may all seem quite removed from the issue of whether more intensive GM monocultures would free up more land for biodiversity and wildiife. But I hope the link is clear? We should beware of leaving out the social and economics aspects of these issues – or of being too naive or simplistic about them.

      If things pan out with GM intensification as they sometimes do with energy intensification, then societies could easily end up at the same time intensifying existing farming land AND extending intensive production into presently less disturbed land (for instance for less efficient food chains like greater meat consumption, or for biofuels).

      Nothing is sure in this. But it is clear that simplistic arguments like those advanced in favour of a straightforward positive effect from GM, are missing a big part of the story – and are therefore potentially highly misleading.

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