It's been a while since I've written on GMOs, but it may be time to start again. Recently, a huge amount of attention was given to an IARC report suggesting that glyphosate (brand name: Roundup), one of the most common pesticides, may cause cancer. The dangers of glyphosate have been a favorite whipping boy of GMO critics, since the reason so much glyphosate is used is that there are GMO crops resistant to it, and that was before there was any credible evidence of danger. There's a bit of a debate on about how good this recent IARC report is (for a nice summary, see here), but I'm going to ignore that bit of the argument for now. What about the

Hypothetically, let's pretend we could say for certain that glyphosate causes cancer.

a) Would this be sufficient reason to stop using glyphosate?

b) Would this imply that GMO's are a bad idea?

The answer to both of these questions is no.

Risk is relative.

The choice of whether or not to use a thing or consume a thing can not be based on absolute risk, it must be based on relative risk. If you have an airbag in your car, there's a risk that it will kill you, but I don't think anyone would argue that stripping the airbag out of your car is a good idea. If you get in a plane, there's a risk of death, but if you drive the same number of miles, the risk is nearly 10 times higher.

So the question is should not be, "Does glyphosate cause cancer?" but rather, "Is glyphosate worse than the alternative?"

And that "worse" contains a lot of things. Going back to my plane example, let's say plane travel were twice as dangerous as driving, but you wanted to travel from the US to Europe. Would you get on a boat? We have to consider relative risk alongside relative cost and relative convenience. It might be safer to take the bus, but most people would rather drive themselves.

What are the alternatives to glyphosate? There are some "organic" herbicides and methods, but these cost more and are less effective. Commercial products for use in industrial farming such as atrazine are more toxic than glyphosate, and linger longer in soil and contaminate groundwater (glyphosate is readily broken down by microbes in the soil). Now, I'm all for reducing our reliance on industrial farming, and I'd love to move towards a world where sustainable agriculture is the norm, but that's a separate question.

Glyphosate is not GMO

But ok, let's take this hypothetical even further and say that glyphosate is even bad from a relative standpoint. Pretend the most ardent critics are right, and Roundup is the evil spawn of big business and the devil. What does that tell us about GMOs? Well, nothing really.

As I've argued over and over, genetic engineering, like any technology, can be used for good or bad purposes. Some uses are almost sure to be bad in the long term, but that does not mean the technology is a bad thing, any more than the fact that cell phones can detonate bombs suggests that cell technology is a terrible thing.

Some critics argue that there are better alternatives to GMO technology, so it's not worth pursuing. But imagine I came to you in 1945 and suggested that rocketry wasn't worth pursuing. "Rockets aren't very accurate," I'd say, "and they're only used to launch explosive payloads to hurt people anyway." If people had stopped pursuing the technology then, we wouldn't have satellites, interplanetary travel or GPS.

And when there aren't alternatives?

Demand for staple crops will begin to outstrip supply in the coming decades if current trends continue. From Long et. al.

And in any case, this line of thinking is hopelessly naive. As a recent paper in Cell points out, crop yields aren't growing fast enough to keep up with human demand:

"Although a significant proportion of the global population has suffered malnutrition over the last 50 years, it has been the result of failures in access to food, not in its global production. Indeed, over this period, we have seen surpluses of the major crops, which make shortages a very distant concern for most of the population[...]

So why bother worrying about food security now? One reason is that these global surpluses in staple crops have influenced the progressive decline in spending on plant science research and crop improvement, evident at the global level. However, this shift in funding may be myopic in the face of current global population and food consumption trends. Notably, the global population is expected to increase from just over 7 billion today to 9.5 billion by 2050, a 35% increase. An increasing proportion of the population will be urban, resulting in diets shifting increasingly from staples to processed foods, fortified with more meat and dairy products, which require large amounts of primary foodstuffs to produce[...]

If current rates of crop yield improvement per hectare are simply maintained into the future, supply will fall seriously below demand by 2050."

Stephen Long et. al. argue that one of the best targets for improving this situation is engineering plants to increase their photosynthetic activity. We've learned an enormous amount about photosynthesis in the last 50 years, and it's clear that our current crops are fall well below their maximum possible productivity. Increasing yield through photosynthesis would allows us to grow more food on less land and could allow us to keep up the human population.

Photosynthesis... yeah, it's complicated. This image gives me unpleasant flashbacks to my metabolic biochem class in college. From Long et. al.

Then again, critics might argue, improving photosynthesis with GE was promised 20 years ago why hasn't it happened? It turns out, photosynthesis is really complicated. This fact, coupled with the decrease in funding for plant-based research mentioned above, means that the hoped-for gains haven't been realized. But with new genome editing techniques, we will be able to modify more features of photosynthesis in more crop types, and potentially make this happen. Getting back to my previous analogy, people were exploring the possibility of rocketry for space travel 50 years before it became reality.

We're on the cusp of a biological revolution. Can we please stop arguing about whether the technology should be stopped (it can't be), and instead start talking about the best ways to move forward? We're hopelessly behind on public understanding of these issues, and there are many real concerns about our agricultural economy. Let's start figuring out answers to those questions, and allow for the possibility that genetic engineering maybe one tool we can call on to help.