Lawrence Solomon: ‘Can Earth handle 29 billion people? Easy’

'At 29 billion, Earth’s population density would be about 215 people per square kilometer, about the same as Switzerland’s, a country known for the Swiss Alps, a pristine environment and an economy that runs like clockwork...
If all 29 billion people in the planet lived in the U.S., its density would be 3,165 people per square kilometer, less than the District of Columbia’s 4,100 and less than half of Singapore’s 7,300. Singapore is one of the world’s healthiest and most affluent countries, with a longer lifespan and higher per capita income than the U.S. or Canada. It is also one of the world’s greenest.'