Not the End of the World: How We Can Be the First Generation to Build a Sustainable Planet

by Hannah Ritchie

I’m also a misfit scientist at the University of Oxford. We’re ‘misfits’ because we do the opposite of what people expect academics to do. Researchers tend to zoom into a problem, to get as close as possible and pick it apart. We zoom out. My job is not to do original studies, or to make scientific breakthroughs. It’s to understand what we already know. Or could know if we studied the information we have properly. Then explain it to people: in articles, on the radio, on TV, and in government offices so they can use it to move us forward.

Globally, average life expectancy has increased from around 30 to more than 70 since the start of the 20th century. In the poorest countries too, life expectancy has improved substantially. In Kenya, Ethiopia and Gabon, it’s 67 years. The average across sub-Saharan Africa as a whole is 63 years.

To put this development in perspective, every day for the last 25 years there could have been a newspaper headline reading, ‘The number of people in extreme poverty has fallen by 128,000 since yesterday’.v

As a result, the world has already passed ‘peak child’. According to statistics compiled by the United Nations, the number of children in the world peaked in 2017vi and is now falling. Take a moment to think about what that means: there may never be more children in the world than there were in 2017. Global population growth will peak when all these children reach old age. The United Nations projects this will happen in the 2080s at 10 to 11 billion people.19 From there, it expects the world population will start to shrink.

What about ‘degrowth’ – shrinking the economy – instead? This argument hinges on the fact that, historically, economic growth has been linked with more resource-intensive lifestyles. As we got richer, we used more energy from fossil fuels, had a higher carbon footprint, used more land and ate more meat.

In rich countries carbon emissions, energy use, deforestation, fertiliser use, overfishing, plastic pollution, air pollution and water pollution are all falling, while these countries continue to get richer.vii The idea that these countries were more sustainable when they were poorer is simply not true.

The small particles produced when we burn wood can get deep into our lungs and lead to a range of respiratory and cardiovascular problems, including heart disease and cancer. We know that early humans were exposed to these pollutants because we find them in their remains from hundreds of thousands of years ago. When researchers looked at the preserved teeth of hunter-gatherers from Qesem Cave in Israel from 400,000 years ago they found pollutants from charcoal in them.12 These pollutants, they suggest, came from indoor fires for the roasting of meats.

The

Should note indoor pollution from gas.

By 1900, emissions in the UK had hit 10 tonnes per person.9 In the US, as much as 14 tonnes. Compare that to just five tonnes in China, and around one tonne in India today. It’s not hard to see why many growing economies get mad when the rich world tells them to stop burning coal.

These perspectives can be useful. But when we turn climate change into a blame game, there is no end to it. People are not really fighting about the numbers. They’re fighting about what numbers they should be using in the first place. If they don’t agree on that – which they often don’t – the fight goes nowhere useful. This battle has plagued international climate agreements for decades. The US and EU blame China and India, who then pick another (very reasonable) metric and fire it back.

As we get richer we gain access to these things, and our emissions increase. But that’s not the full story. We see large differences in emissions among rich countries. Culture, transport infrastructure and our choices of energy sources matter a lot. Living standards in Sweden are just as good as they are in the US, if not higher. Yet the average Swede emits just one-quarter of the emissions of the average American, and half as much as the average German. And some middle-income countries – such as China and South Africa – have now overtaken many richer countries across Europe in per capita emissions. And this is not just because rich countries have exported their emissions elsewhere.

This ‘offshoring’ of emissions is an important concern. But, thankfully, it is not the whole story. Researchers can use trade data across the world to adjust for the carbon that is emitted in the production of goods that are exported or imported.12, 13 When we account for all these traded goods we get what are called ‘consumption-based emissions’: for the UK, these not only reflect the emissions produced within the UK’s borders but also those involved in all of the goods it imports from overseas. In the UK, GDP per capita has increased by around 50% since 1990.ii Domestic emissions have halved. Consumption-based emissions – those that adjust for ‘offshoring’ – have fallen by a third. It’s not true that the UK has sent all its emissions overseas.

But there is one thing that will trump EVs in our efforts to drive down our transport emissions, and that’s not having a car at all. I live in London, where having one would be more hassle than it’s worth. I can hop on the Underground and cross the city much faster than the queued cars, emitting very little carbon in the process. The rest of my family can’t do this: they live in a small town where the public transport is not great. It’s even harder for my extended family who live in a tiny village in the countryside, where the nearest shop is miles away. People often picture eco-friendly living as rural. Living on your farm in the countryside is the green thing to do. Living in the packed energy-guzzling city is what’s wrecking the planet. In reality, it’s the opposite. There are clear environmental benefits to cities: we can build efficient, connected networks for travel.39 When we look at the travel emissions across towns and cities we find a clear pattern: people in denser cities emit less.40 Part of bringing down our transport emissions will involve rethinking our living spaces. Many European cities are making good progress here. Cars no longer take centre stage, pedestrians and cyclists do. Cities not only become calmer, less polluted places to live, they also function much more efficiently. There’s nothing less efficient than having roads filled with cars bumper-to-bumper. A well-designed combination of cycle lanes, pedestrian walkways and high-speed public transport...

Should I use the dishwasher or the sink? (Unless you use cold water, or hot water very sparingly, the dishwasher wins.)

2.5 million years ago,

Should be billion!

Researchers at Harvard University have loudly pushed against this backlash.29 A meta-analysis covering 30 studies found that omega-6s lowered the risk of heart disease: those with more in their bloodstream were 7% less likely to develop it.30 Another study followed around 2,500 men for an average of 22 years, and found that those with the highest blood levels of omega-6s had a much lower risk of dying from any disease. Studies show that they lower cholesterol and blood sugar.31 And the American Heart Foundation found that getting 5% to 10% of your calories from omega-6s reduces your risk of heart disease.

This is similar to the concept of ‘offshoring emissions’ from the last chapter. Studies have looked at how much deforestation could be attributed to the foods a country imports.38 This analysis is difficult to do without closely tracking foods throughout the supply chain (which companies should be doing much more of). But the data we do have is surprising. It suggests that most of the world’s deforestation is driven by demand in domestic markets. Around 71% of it. Beef – again – is the biggest culprit here since it’s often consumed close to home. Much more soy, palm, cocoa and coffee are consumed internationally. Overall, just under one-third (29%) of deforestation happens for the production of goods that are then traded. I was taken aback by this finding: I had thought global trade would contribute more.

Around half of the world would not be alive today without the invention of synthetic fertilisers. Several scientists have separately estimated how many people the world could support without these added nutrients, and all converge on a similar figure: around half as many.10 –12 In the tropics, the contribution of fertilisers might be even higher. That is why conversations about whether the world should go organic or not get so messy. The reality is that the world cannot go organic. Too many of us rely on fertilisers to survive. As we’ll see later, many countries can reduce the amount of fertiliser they use without sacrificing food production, but we can’t do this everywhere.

Of course, we now know that his predictions did not come true. That’s totally fine: nearly everyone who makes predictions about the future turns out to be wrong. What makes his book so terrible are the inhumane policies he advocated for based on this strong (and wrong) conviction. World population had to be strictly managed. Humans were cancer – a reproducing organism that had to be controlled. As he put it: ‘we can no longer afford merely to treat the symptoms of the cancer of population growth; the cancer itself must be cut out’. In the US and other rich countries, he discusses the option of adding temporary sterilants to the water or food supply.ii Rather than providing financial support to families, ‘responsibility prizes’ could be handed out to couples who reached five years of childless marriage, or men who accepted irreversible sterilisation. Another idea was to have special lotteries where tickets were only handed out to the childless. That’s nauseating. But it’s nothing compared to his suggestions for ‘underdeveloped countries’. Not only did he suggest sterilisation programmes, but he also proposed a ‘triaged’ system of who should be left to starve to death. Some countries could be redeemable – they might be able to dig their way out of it. But some countries were a lost cause. Rich countries should withdraw any food aid and support, and just leave them to die. It’s not clear how committed Paul R. Ehrlich really was to these ideas. But many – including senior offi...

The bigger question is how we can possibly lose half of the food we produce before it even reaches our plates. That is a woefully inefficient system. The reason is that we feed livestock and cars, not people. The world produces 3 billion tonnes of cereals every year. Less than half of this goes towards human food; 41% is fed to livestock, and 11% is used for industrial uses, like biofuels. That global allocation is surprising, but when we look at specific countries the balance is jaw-dropping. Poor countries use nearly all of their cereals for human food. In Chad, Malawi, Rwanda, India, for example, the number is more than 90%. When you can only just produce enough for everyone, you can’t afford to put it into cars, or feed it to other animals. Diverting food away from humans is a luxury. Many richer countries take this luxury to the extreme. The amount of maize that the US puts into cars for biofuels is 50% more than the entire African continent produces.

To support 8 billion through hunting and foraging we would need 8,000 to 800,000 million km2 of viable land. That’s 100 to 10,000 times the amount of land we have on Earth. That’s also ignoring the inconvenient reality that we’d wipe out all mammals along the way. What about pastoralism? Small communities that rely on livestock? That is not much better than the most productive foraging societies. We’d need around 3,000 to 8,000 million km2. Or 10 Earths.

For more traditional farming in one place we’d need between 8 and 80 million km2 which – at least towards the lower end – is much more realistic. But this would only work if everyone ate a plant-based diet so we could feed them efficiently on croplands. And we’d probably have to cut down many of our forests along the way. With modern farming we could feed 8 billion people on much less land. Possibly as little as 4 to 8 million km2 if we achieve very productive farming across the world and move to plant-based diets (which are very big ifs).

Dairy milk tends to be higher in calories and protein.

Not true for soy.

When I was talking to one of my previous bosses – Mike Berners-Lee – about food losses, he remarked that it was ‘just a Tupperware problem’. That’s stuck with me ever since. He’s right. If the world had more Tupperware it would lose a lot less food. In fact, there are studies to prove it.36 Researchers in South Asia tested what difference it would make to switch fabric sacks for cheap plastic crates. When farmers and distributors transport their food in sacks, you can imagine how bruised and battered their tomatoes and mangoes are by the time they get to the market. As much as one-fifth of food transported this way has to be thrown away. When they used plastic crates instead, these losses were reduced by up to 87%; rather than losing one-fifth, they’d lose as little as 3%.

Vertical farming is only feasible – and even then, barely feasible – for a few crops. Fruits and vegetables are expensive to grow but also profitable for farmers. The higher costs of vertical farming might just be supported by crops like lettuce, mushrooms and tomatoes allowing some producers to break even or make a small profit. But we can’t produce any of our staple crops using vertical farms. Maize, wheat, rice, cassava and soybeans are where the world gets most of its calories from. These crops are so cheap that it becomes woefully expensive to try to grow them indoors. One study estimates that it would cost $18 to produce a loaf of bread from wheat grown in an indoor farm. And that’s just to pay for the lighting.

But we’ll still need the land for the panels. Once we include the land use of the electricity source, the land savings from vertical farms can disappear entirely. In some cases, they’ll actually need more land than a normal field.

There were never more than 5 million people alive at any given time during this period. Nearly 2,000 times less than live on Earth today. A global population half that of my home city – London – drove hundreds of the largest mammals to extinction. That is hard to imagine. It goes against the common environmental narrative we see today: that ecological damage is the result of uncontrollable population growth. If a mere 5 million could transform the whole mammal kingdom, this is obviously not true.

A single-use plastic bag: the sin of any environmentalist. Many of us know the agonising pain of turning up at the supermarket, then realising you’ve left your reusable shopping bags at home. The next 10 minutes is a comedy show, seeing how many items you can stuff into your pockets, clutch in your arms, and even grip between your teeth. You will not let the team down by asking for a plastic bag. I do the same. Even though I know better: the data shows us that the occasional plastic carrier bag is not that big a deal.

He estimated that in 2003, almost 30% of the world’s fish stocks were defined as ‘collapsed’. What he then did was simply extend that trend line out until it reached 100%. He assumed that fish stocks would just continue to collapse, one after another, until they all had in 2048. It’s a somewhat innocent extrapolation. For a scientist it’s an interesting thought experiment: ‘If things carry on as they have in the past, when would this reach 100%?’ I often do these calculations myself. They’re fun. But this approach highlights a fundamental problem that we’ve seen over and over in this book. It’s one that feeds into the doomsday mentality that we’ve locked ourselves into. We extrapolate exploding population numbers and panic that they will never stop growing. At least, until they crash.

This probably comes back to the good old ‘natural fallacy’: things that seem more grounded in ‘natural’ properties must be better for us, where natural equals good, and unnatural equals bad. We’re sceptical of synthetic stuff that comes out of a factory. It’s easy to mock this ‘natural is best’ type of thinking. In the past I’d brand it as ‘unscientific’ because it is unscientific. But ridicule has never been an effective way to drive change, and it’d make me a hypocrite because I haven’t totally rid myself of these feelings either. I still get the instinctual pull towards ‘natural’ solutions. Working against it takes repeated, and sometimes uncomfortable, effort. Yet it’s something that we need to overcome. The fact that our intuitions are so ‘off’ is a problem. At a time when the world needs to eat less meat, we’ve seen a pushback against meat-substitute products because they’re ‘processed’. When we need to be using less land for agriculture we’ve seen a recent resurgence in organic, but more land-hungry, farming. When more of us need to be living in dense cities I hear more people dreaming of a romantic life in the countryside with a self-sufficient garden plot.

The reality is that we will not fix our environmental problems through individual behaviour change alone. This became obvious during the coronavirus pandemic. The world spent most of 2020 at home, at a huge cost to the quality of life for millions of people. Our lives were stripped back to the bare minimum. There were hardly any cars on the roads or planes in the sky. Shopping malls and entertainment venues were shut. Economies across the world tanked. There was a dramatic and almost-universal change in how all of us lived. What happened to global CO2 emissions? They fell by around 5%.

G. P. Peters, ‘From production-based to consumption-based national emission inventories’, Ecological Economics 65, 13–23 (2008). 13 G. P. Peters, S. J. Davis & R. Andrew, ‘A synthesis of carbon in international trade’, Biogeosciences 9, 3247–76 (2012).

D. Rybski et al., ‘Cities as nuclei of sustainability?’, Environ Plan B Urban Anal City Sci 44, 425–40 (2017). 40 R. Gudipudi et al., ‘City density and CO2 efficiency’, Energy Policy 91, 352–61 (2016).

S. Fennell, S. J. Davis & A. Mohammed, ‘Decarbonizing cement production’, Joule 5, 1305–11 (2021). 48 ‘Concrete needs to lose its colossal carbon footprint’, Nature 597, 593–94 (2021).