kowloon walled city

An article in the New York Times asking how many people could keep notes of Manhattan "Manhattan package as strong as Kowloon Walled City, river to river, get stuck on average 65 million people."

I think in many ways is more illuminating to think about less extreme scenarios. Think of New Jersey, which is not really a farm full. It contains, however, five times more people per square mile as California. In other words, if the Golden State were as close as New Jersey an average of over 188 million people. And California is a fine place to live. Thanks to its mild climate, Californians use very little energy for heating and cooling of offices compared to most Americans. According to 2005 data, the average California had half the footprint of the average American about this. And yet, a Californian who was in New Jersey, the level of population density would be even lower per capita CO2 emissions, as many cars would travel shorter distances and a greater proportion of the population would be walking / cycling / transit by the time. And although this of course would be a dramatic transformation, my point is that unlike Manhattan interpretation of Kowloon Walled City is not a bad idea. New Jersey is a strange neighborhood, as an accident of history. New Jersey is not particularly intense! In fact, small cities (Trenton, Newark, Camden) are all well below the peaks of its population history.