Their paper, 'Human Engineering and Climate Change' - forthcoming in Ethics, Policy and the Environment, but available in a pre-publication version (1) - has already attracted a reasonable amount of media interest, and it's not hard to see why. The headline proposal is that we could engineer people to be smaller, on the grounds that smaller people require less food and fuel; a population that is smaller would have less environmental impact.
A small part of this - and I'm genuinely fond of this idea - is that heavier people wear out shoes and carpets more quickly, so are more resource-hungry. On the other hand, as one of my students has pointed out, short people take more steps to get across the room; the carpet might actually suffer more. Moreover, a small person has a greater surface-to-volume ratio, and so would lose heat more quickly, possibly requiring more central heating and more food.
Other ideas that they consider include the notion that we could use biotechnology to make people more predisposed to solidaristic behaviour. They would then be more likely to adopt the interests of others, and future generations, as their own, and so be more likely to avoid behaviours believed to contribute to environmental catastrophe.
The paper also raises the possibility that we might introduce a mild intolerance of red meat into the population. This would help combat climate change because a carnivorous diet is massively environmentally damaging; woodland is a carbon sink, and so felling it to make way for grazing releases carbon dioxide into the atmosphere and, at the same time, reduces the rate at which its scrubbed out. Moreover - and there's no delicate way to put this - cows fart. Methane is a greenhouse gas, and it degrades to produce carbon dioxide and water vapour, also potent greenhouse gasses. Making people less likely to eat meat would remove demand, meaning fewer cattle farm, and that could only be a good thing for the environment.
While it's easy enough to laugh at some of the suggestions, they do belie a serious point: climate change is a problem, and we don't have a solution. Market fixes don't seem to do the trick; geo-engineering might, but it is risky, and some forms of it worryingly so. Human engineering might be risky as well but if we're seriously considering geo-engineering, then, by extension, we should probably be thinking about human engineering, too.
Some might say that the engineered children of the future would be harmed by our tinkering, but this is not a given. For example, a reduction of 20 centimetres in average height would not lead to a fall in average welfare. On the other hand, being intolerant of red meat could be considered as a harmed state; the world's vegetarians could be carnivores if they wanted without becoming ill, but meat-eating would be permanently barred to the genetically intolerant. But the wrong of causing harm may be reduced if that harm is for good reason, and averting catastrophe might be a good reason. Besides, being born into the world of increased drought, famine and natural disasters brought about by global warming is, by the same token, no less of a harmed state.
Three cheers for the three authors' vision. Pondering outlandish possibilities might just lead to a solution to environmental problems. But I do have a couple of problems with the paper. One has to do with the claim that, though some may find genetic engineering solutions unacceptable, this is not a reason to prevent such solutions being made available.
To say that something is available is to say that people can take or leave it but if climate change really is a problem of the magnitude that experts think it is, then allowing people the option to leave it may be deeply irresponsible. If the problem really is that great, some mandate might be in order, for everyone's sake. (The paper's authors do not want to reduce liberty; but is liberty really sacrosanct?)
Moreover, Liao and his colleagues admit that, for example, the short might suffer certain sexual and career disadvantages in comparison to the tall. But if that's true, a parent-to-be who opted for a shorter child in a world where others do not take that option would be embarking on a course of action that would put their child at a disadvantage - and this might be out-and-out bad parenting. If everyone opts for shorter children, the disadvantage would vanish - but now we're back to mandates.
Most importantly, technological solutions mightn't be the best fix for environmental problems anyway. Environmental degradation is a problem about external costs. It reflects the fact that the market price we pay for goods does not reflect their 'true' cost. The market pays no heed to cow farts. This is why market solutions to climate change are doomed to struggle. But there is a way around this, and it's to abandon or radically rework the market, so that the price to the consumer accurately reflects the external costs of a good. This would be a radical move; and making a non-market economy efficient and wealthy would be a difficult task.
But engineering our kids to eat less beef is hardly a doddle, is it?