Over the past two centuries, the average height of humans in developed countries has increased; microevolution in action, although it can be argued that this effect is more due to improved health care and nutrition than to any significant genetic changes. One doubts that tall people have more children than shorter ones. In any case, this shows that it is possible to breed humans for simple changes in stature, just as we have bred dogs and other animals of different types and sizes. Leaving aside the shadow of eugenics for the moment, I want to suggest that, instead of breeding taller humans, we should breed ourselves shorter -- significantly smaller.
Taller people are not necessarily healthier, smarter or more successful, just as shorter people are not less well off, unhealthy or of lower mental acuity in general. However, it is clear that taller or bigger people need and use more resources than smaller folk. Very tall people, aside from being better at basketball, have serious problems with doors, cars, chairs, clothing, and other standard acoutrements of civilization than normally sized people. Moreover, very tall people and certainly oversized (that is, wider) people have health issues that occur less frequently in smaller (or thinner) people.
We already have some small people with us, those with dwarfism of various types and degrees, often proportionate (sometimes called midgets), for example. Although they may have some associated health issues, they can live happily, even in our normal-sized cultures. Now imagine what would happen if everyone was smaller, say about one meter tall, give or take -- child, or hobbit size you might say.
There would be significant benefits to humanity and the world if we were all smaller. If houses, cars, roads, etc. were designed for people one meter tall, instead of 1.7 m tall (5 ft 6 in, the approximate current average), and were proportioned about the same as hobbits, or normal five year old children, our average weight would be only around 20 kg or 45 lbs. This would solve or mitigate all sorts of obesity issues at the very least! It would also mean that we would need less food and numerous other resources to live a healthy and fulfilled life.
A world of hobbits could include at least twice the number of people as our world for the same resource usage. This would solve the "overpopulation" problem many seem to worry about. In any case, being 1m tall would greatly reduce your "carbon footprint", not to mention your actual footprint! Small shoes should be cheaper to make, transport and stock. This saving applies in spades for houses and cars, and all that they entail. Instead of 8 ft ceilings, queen sized beds, doors 32" wide, and so on, we could have 5 ft ceilings, and everything else proportionately smaller too. A 500 sq ft house would serve as well as a 1500 sq ft one does today. Think of the heating and air conditioning savings that could accrue, not to mention the capital cost of building and buying the house. Smaller schools, malls and other buildings would multiply this benefit.
In particular, cars could be four feet wide (1.2 m) instead of six or more, and much shorter in length and height as well. This would reduce their weight by 70% or more, while increasing their gas mileage accordingly. Trucks could also be smaller since most of the cargo they carry would be reduced in size and weight accordingly. I suspect that less human and metal momentum would make traffic accidents less serious as well, even without reducing speed limits. Of course, smaller vehicles would mean narrower roads, smaller bridges, and other infrastructure, all saving additional cost and resources. Lower taxes maybe? (dream on).
Narrower roads and smaller buildings allow more people to live in the same area, or the same numbers to live in less than 35% of the area for cities and towns. Smaller cities means quicker commutes, less pollution, and freed-up land for agriculture, recreation or nature. One can envisage all sorts of benefits that would accrue if humans were about one meter tall on average. Even space exploration would be easier and less costly, given the cost per kg of placing humans into orbit and maintaining them there. Little green men, meet little pink men!
With everything human much smaller, unchanged natural environments - trees, plants, animals, rivers, etc. - would seem larger to us, but human activity and interactions would be largely unaffected. There is little, aside from most sports, that would suffer from making people significantly shorter, and sporting achievements should be easy to reset for smaller folk -- scale down Olymoic records, football fields, etc. In developed countries, there are few jobs that still require large people, aside from the arbitrary standards for firefighters, military, etc. Indeed, smaller soldiers would be harder to target, and could fly smaller airplanes, or drive smaller (and cheaper) tanks. Big construction equipment could be just as easily driven by smaller workers, as could farm equipment.
With some joint effort by all nations, coupled with advanced genetic knowhow, we could easily breed ourselves to have smaller stature, and could probably achieve the one meter average within, say six generations, so that by 2200, the goal would be achieved and we could start reaping the benefits noted above. This would go a long way to addressing the climate change worries that some people have. In principle, meter high humans, with associated right-sized infrastructure, should used less than a third as much carbon as we full-sized ones, even without other changes. If we can breed dogs one quarter the size of wolves, reducing the average human height by only 40% should be easy.
This is all tongue-in-cheek, of course, I am not seriously proposing that we try to shrink humans over the next 150 years. Not only would that proposal be laughed away as a joke, impossible to enact meaningfully, and attract lots of negative responses, but it would raise the ugly prospect of eugenics, the use of genetic manipulation and coercive laws to make humanity "better" according to some elite goal or standard. Eugenics has had a nasty track record in 20th century Germany, the USA and elsewhere. If we start breeding smaller humans, why not smarter, or more beautiful ones? That way leads to a Brave New World that inevitably results in totalitarian measures, and groups of people judged unfit, or of lower importance, by those deemed superior somehow. I certainly do not want to go there.
So, people as hobbits is an interesting exercise, but it must remain a thought experiment. We will have to find other ways to limit our footprints on the world we have, and make more efficient use of its limited resources. Alas, our track record for doing that in the developed world has been less than stellar. So unless everyone is willing to shrink their stature, we should all try harder to shrink our negative impacts on the planet. If we all did that, we would not have to wait 200 years to see the benefits.
