Graeme Maxton

Climate Change Economist and Author

The birthrate doesn’t matter now

When it comes to slowing the pace of climate change, how important in the human birth rate?

For the last 50 years, it was very important. Now, it isn’t very important at all.

There are nearly 8bn people in the world today. Every year, about 140m babies are born, more than ever before. Every year, around 60m people die. (It will be 3-4m more in 2021 because of covid-19.)

So, the population is rising by around 80m a year, just as it has for each of the last 20 years.

Without change, the population will rise by around 800 million over the next decade.

What effect does that have on the pace of climate change?

To avoid anything worse than a 1.5ºC rise in global temperatures*, the carbon budget** remaining at the start of 2021 was 295 Gt. At the current rate of emissions (40+ Gt a year), that leaves less than 8 years to avoid runaway climate change. Even then, societies will only have a 50:50 chance.

Let’s assume that the population continues to grow as now. Over the next decade, that would mean an average of 400m extra mouths to feed – a 5% increase in the current population.

At worst then, all these births will reduce the time remaining by less than five months. But it will be much less than that, because the global average carbon footprint of people under the age of 10 is very small. It’s about 85% lower than people over the age of 40.

In other words, all these new babies will have a miniscule effect on overall emissions. They would increase the total by a few percent – and bring the catastrophe forward by a less than a month.

Cutting current emissions is what matters

When it comes to climate change, it’s the size of the existing population that is critically important, not those who are yet to be born. It is the 8bn who are already alive which will create most of the emissions in the next decade. Of course, those additional 800m people would have a huge impact in the following 60 years. But it will be too late by then to change what’s happening. It’s the next eight years that matter.

Rather than putting effort into cutting the number of births, societies should focus on cutting current emissions. If these can cut by 7% a year, so they are 60% smaller in 2030, then humanity will have an even chance of avoiding uncontrollable warming.

That does not mean, however, that each person should try to cut their emissions by 7% a year individually. Acting alone, by changing consumption habits, will not have anything like a big enough impact now.

To work, it is the businesses which pollute the most – the fossil fuel companies, the cement producers and those in the transportation sector – that must be compelled to cut their emissions by law. Societies will also need to reform farming and stop all deforestation.

Those are the steps needed to avoid a climate catastrophe.

*This article says we had a carbon budget of 230-440 Gt in 2020. The midpoint is 335. Take off 40Gt emissions for 2020. That leaves a remaining budget of 295 Gt as of 2021, to have a 50:50 chance of avoiding runaway climate change.

**The ‘carbon budget’ is the amount of carbon (or equivalent from other sources) which can be released into the atmosphere before it kicks off a series of chain reactions, leading to an unstoppable warming which will last for centuries.

baby maxton

A decade of population growth will have very little impact