I also take a slightly less humanist perspective on this whole thing. While the interconnectedness of the world vis-à-vis climate makes ignoring some aspects of human damage a world away hard to ignore, such as the rain forest, it's still their country. They can do whatever the hell they want to fuck up their area of the planet. I'm worried about my area of the planet.
Further from a humanist perspective is that I don't care how many poor farmers die in Brazil or Ethiopia. It's their problem. Not only should they just take care of it themselves, trying to force our help on them doesn't do anyone any good. They need to solve their own problems.
And we live in America! Most of our problems are comparatively so easy to solve it's a wonder we haven't done so already. Want to increase population density and stop urban sprawl? Subsidize large, urban, multi-unit complexes. Give tax breaks to eletrical firms willing to install solar and wind in urban areas. Give tax breaks to building owners who install solar, wind, or farms on roofs of buildings. Start growing locally in large, multi-story farm buildings.
For the next calculations, I'm going to rely on The Natural Way of Farming: The Theory and Practice of Green Philosophy by Masanobu Fukuoka.
That's actually one of my favorite ideas. Large farm buildings, with a foot print of just half an acre, and 30 floors, that's 15 acres, or enough to feed between 100-500 people on vegetables alone. With the efficiencies allowed by constant illumination, robotic harvest, and nutrients flowing from floor to floor, that number could reasonably be doubled or tripled.
Now think even further. One floor is nothing but fish, and the water from the giant tanks is filtered up through the plants to feed them, back down into the fish tanks. These are not new ideas, but the wherewithal to get it done has not yet been found.
Many areas of the world are fucked. Let's face it, they are. There's nothing we can do unless we want to kill everyone there and just start over. They're fucked, their land is fucked, their cities are fucked. The best course of action for us is to pull inward as much as we can. I'm not talking isolationist nonsense, but a focus on our own abilities. We want to produce as much as we can, be as self-sufficient as possible.
They're going to fuck themselves, so we must actively try to to fuck ourselves as little as possible. Our only problem with our population is that it continues to grow outward in urban sprawl. If we can reduce that, and mate it with large scale development in renewable resources, be it food, energy, and materials, we can only better our position.
Norman Borlaug, who recently died, was famous for discussing population problems. His solution back in the 60's was to increase food production.
That's what Norman Borlaug and his colleagues achieved in the 1960s and 1970s with the Green Revolution that staved off famine for millions. Yet, "there can be no permanent progress in the battle against hunger until the agencies that fight for increased food production and those that fight for population control unite in a common effort," Borlaug said in his acceptance speech for the Nobel Peace Prize in 1970. "[Man] is using his powers for increasing the rate and amount of food production. But he is not yet using adequately his potential for decreasing the rate of human reproduction. The result is that the rate of population increase exceeds the rate of increase in food production in some areas.
Again, this is only a problem if we feel the need to force our help on other countries. The fact that India is choking under the weight of one billion people wallowing in ghettos is not our problem. It cannot be. There is no solution. I'm not heartless, I'm a realist. Trying to solve the massive problem is Sisyphean, and the endless aid to Africa all but proves that. Let them die. Our only concern is the possibility of a super-germ incubating in the population and making the trek over here. Other than that, we should not only not worry, but actively ignore. If they ask for help, do not give it to them. Their sinking boat has the potential to bring us down, too.
Another Inconvenient Truth: The World's Growing Population Poses a Malthusian Dilemma (ScientificAmerican.com)