Are There Too Many People on the Planet?

The Chart Everyone Knows, and the One That Corrects It

Write down first: are there too many people? Then the charts — and there are a lot of them.

You'll see the famous one, where the human population stays nearly flat for thousands of years and then shoots almost straight up. It's alarming, and it's true. Then comes the chart that changes its meaning: the growth rate peaked at 2.2% and is now about 1.1%. We're still adding people fast, but we've been adding them more slowly every year for fifty years.

Other things worth noticing:

• About 60% of the world's people live in Asia. About 3% live in South America.
• The US has around 33 people per square kilometre; Japan has around 350. At Japanese density, the US would hold 3.5 billion people.
• Some countries now have negative growth — more deaths than births. Make sure you can say why that happens.
• Three charts show that families have fewer children as child mortality falls, as income rises, and as girls stay in school longer. Whether one causes the other is the question to sit with.

Optimists and Pessimists

You'll work in a group around one of two positions, and both are serious:

• Optimistic. We've feared this for centuries and always found a way through. Growth is slowing on its own, for reasons we understand — richer countries and educated girls mean smaller families. The projection has the population peaking near 11 billion and then levelling off. The environmental problems are hard, not impossible.
• Pessimistic. Some resources are already scarce. Climate change is here and gets worse as both population and living standards rise. Even if people are fine, we're taking land and fresh water from every other species and driving some to extinction. And the projection might just be wrong.

The history you should know before you argue: in 1798 Thomas Malthus predicted inevitable famine because food grows steadily and population multiplies. In 1968 The Population Bomb sold two million copies and opened with "The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death." What actually happened: famine deaths dropped sharply after the 1960s, China's rice harvest more than doubled, India's nearly tripled, and American corn yields per hectare doubled.

The question at the centre of the week: if humans do fine but other species suffer, does that matter? Do we owe them anything?

Open the Discussion

• Should we trust the projection that the population peaks around 11 billion?
• If it does, will people still thrive at that number?
• Will we run out of resources someday — or invent our way out, the way we have before?

Two numbers to have ready: half of the world's habitable land is used for farming, and 77% of that is used for livestock. Beef produces more emissions per kilogram than any other food by a wide margin.

Before you leave, find a resource to bring on Thursday.

What We Owe the Rest of the Planet

Share what you found, then take the question the whole week has been building toward: if we succeed and everything else loses, does that count as succeeding?

Some history to argue with: protecting nature from people is a surprisingly recent idea. Yellowstone became the first national park in 1872. The Sierra Club came in 1892, Silent Spring in 1962, Greenpeace in 1969, the first Earth Day in 1970, the Endangered Species Act in 1973. Why did it take so long for anyone to think of it?

Finish with something concrete: fresh water, water quality, and biodiversity are what farming threatens most. What would actually reduce that — and would you do it?

Score Your Own Week

What went well, what to improve, what you learned, and whether anything you believed changed. Then the participation matrix. Be honest with yourself.