Major thanks to the Llamabutchers for this, one of the finest pieces of writing I’ve encounted in quite some time.
Reflections On The Tiny Lizard That Scurried Out Of My Way As I Was Heading To The Shops Yesterday Afternoon Or, On Being The Wrong Size
So here's me, 175cm tall and eighty kilograms, and here's my fellow vertebrate, all of two inches long and weighing maybe a gram.
Which led me to musing. With all the problems of the world becoming overcrowded and resources running out, wouldn't things be better if we were smaller? What really counts is our brains, right?
So, we replace our brains with self-assembling nanotech (or possibly quantum) systems that are a thousand times more computationally efficient. That means that for the same level of intelligence, we only need one thousandth the amount of brain - and one thousandth the body mass to support it. Which means a thousand times less impact on the environment.
Since we'd be ten times smaller (lengthwise), we'd each want one hundredth the living area we currently do. That means that with current crowding levels we could increase our world population to 660 billion while consuming just one tenth our current resources.
This has obvious advantages: With 12 billion Japanese, the amount of anime produced would be huge. Blockbuster movies like The Lord of the Rings would be a dime a dozen, thanks to the massive new audience available.
There's other, less obvious rewards. Ever fallen and hurt yourself? No more! It will be impossible to hurt yourself just by tripping over something - your centre of mass is only three inches off the ground. And while your bones and tendons are now a hundred times weaker, they only need to support one thousandth the weight, so they are proportionally ten times stronger.
And the downside? Well, JBS Haldane wrote about this nearly eighty years ago. One is temperature regulation; we are warm-blooded and need to eat to maintain our temperature. As much smaller creatures, we would lose body heat much more rapidly, because the ratio of surface area to volume has increased. But that's a fairly straightforward problem for an advanced civilisation; we already have reverse-cycle air conditioning. (And clothes, for that matter.)
You can go to the original site to read the entire thing, and I most highly recommend that you do. Good, good stuff, boy. My life is a bit better for having read this.