S1·E103 Are there too many of us on Earth?

In a century, the number of humans on Earth has more than quadrupled, rising from nearly 2 billion to over 8 billion. Some believe this is far too many and that we are heading for disaster. Yet, the Cassandras of the 1960s were already saying the same thing when we were not even 4 billion. How many people can the Earth support?