How sensible climate policies will support a growing world population

While energy use per person continues to grow gradually, efficient technologies and use of resources will help to meet net-zero goals

This photo taken on October 10, 2022 shows people walking down Takeshita Street in the Harajuku area of Tokyo. - The global population will breach the symbolic level of 8 billion on November 15, according to the UN. The milestone comes as questions are increasingly being raised about the measures needed to adapt to global warming, as well as about how humanity consumes Earth’s resources. (Photo by Richard A. Brooks / AFP)Show less

“In the human fugue there are eighteen hundred million parts,” wrote Aldous Huxley, author of Brave New World. “The resultant noise means something perhaps to the statistician.”

Huxley published his novel Point Counter Point just 94 years ago; on November 15, UN statisticians estimated that the global population had passed eight billion.

It is not only people; we keep 19 billion chickens, 1.5 billion cows, 1 billion sheep, 1 billion pigs and 1.1 billion domestic cats and dogs. Wild animals — not just lions and pandas, but the innumerable hordes of mice, rats and bats — account for just 4 per cent of the biomass of all mammals.

In fact, like 2022, 1928 was a landmark population year: the number of humans crossed 2 billion, according to modern estimates. This is despite the ravages of the First World War and Spanish flu pandemic that killed 70 million people between them.

World population hits 8 billion — in pictures

Houses cover a hillside in the Petare neighbourhood of Caracas, Venezuela. The world's population hit an estimated eight billion people on November 15, according to the United Nations. AP

Damaris Ferrera with her baby at Damian Ferrera Altagracia Hospital – in Santo Domingo, Dominican Republic – which symbolically named him the eight billionth inhabitant of the world. AP

Barbers on an abandoned train track in Abeokuta, about 70km outside Lagos, Nigeria. More than half of the projected increase in the global population up to 2050 will be concentrated in eight countries: the Democratic Republic of Congo, Egypt, Ethiopia, India, Nigeria, Pakistan, the Philippines and Tanzania. EPA

Newborn babies at Hotel Dieu hospital in Beirut, Lebanon, as the world population surges past eight billion. Reuters

Crowds on Takeshita Street in Tokyo, considered to be the world's most populous metropolitan area. AFP

Nigeria is a significant contributor to world population growth. Countries in sub-Saharan Africa are expected to contribute more than half of the increase anticipated up to 2050, according to the UN. AP

A packed Ipanema beach in Rio de Janeiro, Brazil. AP

Traffic chaos at Ojodu-Berger bus station in Lagos, Nigeria's commercial capital, which has a population of about 15 million. AFP

A crowded market in Jalandhar, India. AFP

A family taking pictures at the Temple of Heaven in Beijing. AP

Commuters waiting for buses in Manila, Philippines, where the city's 12 million population swells by three million during working hours. AFP

Mexico City is home to more than 20 million people. Reuters

Times Square in Manhattan. About nine million people live in New York's five boroughs. Reuters

A busy market in New Delhi, India, part of an urban area where the population is estimated to be 32 million. AP

Commuters at a train station in Hong Kong. AFP

Indian commuters get off trains at the Church Gate railway station in Mumbai, India. AP

A subway station in Seoul. The South Korean capital has a population approaching 10 million. AFP

Demographics have a tremendous momentum: the rising population was hardly slowed by the 75 million people who died as a result of the Second World War, about 3 per cent of people then alive.

The late 1950s also experienced one of the fastest global population increases in history.

These trends caught the attention of the rising environmentalist movement in the 1960s.

In 1968, the influential book The Population Bomb, by Stanford University academics Anne Ehrlich and Paul Ehrlich, wrote: “The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now.”

In the same year, the Club of Rome was founded and, in 1972, it warned in The Limits of Growth of the exhaustion of oil, metals and food.

We have not starved or run out of minerals, but today, the major concern is climate change.

An ever-growing number of people who need air-conditioning, nitrogenous fertilisers and homes made from steel, concrete and glass, seems to mean unstoppable greenhouse gas emissions.

So does the rising population forebode a hot, hungry and crowded planet? And surely we cannot feed, power and move this seemingly relentlessly swelling horde of humanity and other animals, and preserve a liveable environment, without reducing our numbers?

Such alarmist predictions are wrong in four ways.

First, the population is not growing that much any more. The UN thinks we will reach a maximum of about 10.4 billion during the 2080s. Two thirds of people now live in a country with fewer than 2.1 births per woman, below the long-term replacement level.

Barring a truly cataclysmic war, plague, societal collapse, asteroid strike or robot takeover on the one hand, or an unexpected resurgence in fertility or huge extension in lifespan on the other, these forecasts are near-inevitable.

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Second, warnings about overpopulation usually concentrate on East and South Asia and Africa. Indeed, the population in Europe and Japan is set to fall, and the problem will be to attract sufficient immigration to sustain the economy and look after a growing elderly cohort.

But China’s working-age population also peaked in 2014 and its overall population may drop after this year.

Bangladesh, the most densely populated country in the world after small islands and city-states, had a birth rate of almost seven children per woman in the early 1970s; now it is less than two, below the replacement level. Alarms of “third-world” overpopulation are often thinly veiled racism.

Third, the climate problem is not driven by the absolute number of people, but by their lifestyle.

The average American emits nearly 200 times as much carbon dioxide as the average citizen of the Democratic Republic of the Congo. Little Luxembourg pollutes nearly four times as much per person as neighbouring France. A few thousand ultra-wealthy with their private jets and super-yachts outweigh millions of Africans.

Fourth, we use resources ever more efficiently. Land use for food per person has halved since 1960. As agricultural hectarage has declined slightly since 2000, we may have passed “peak land”, a point at which our farming footprint would gradually diminish.

The all-time peak for oil use per person was in the late 1970s, after which it dropped sharply, then flattened out. The rising use of electric cars will probably bring a further downwards trend in the next few years. Carbon dioxide emissions from energy use reached a high in 2013 and have gradually dropped since then.

Energy use per person, though, continues to grow gradually, with the spread of middle-class lifestyles around the planet.

Scenarios such as those of the International Energy Agency show sharp drops in overall energy consumption as we move towards a “net-zero” carbon world by the mid-century.

This comes largely from a shift to intrinsically more efficient technologies — renewables and electric cars that do not shed more than half their energy input as waste heat.

Such forecasts are probably wrong — energy use will continue to rise as new technologies and desires emerge.

The all-time peak for oil use per person was in the late 1970s, after which it dropped sharply, then flattened out

Robin Mills

But with sensible policies, we will decarbonise. And whether policies are good or bad, the now slow rate of population growth — less than 1 per cent per year — is not the decisive factor in achieving the annual falls of more than 5 per cent in greenhouse gas emissions required for net zero by mid-century.

Families, and especially women, should certainly be given the rights and means to manage their fertility and plan the number of children they want.

But we should not instrumentalise this in service of an agenda of population control: it is a matter of human dignity and well-being.

It is a reason not for despair but for celebration that we can sustain eight billion people, their creations and aspirations and, for most of them, in tolerable peace and prosperity.

Human beings are not simply machines for emitting carbon dioxide: as last week’s breakthrough in fusion energy reminds us, each baby is a potential great scientist, political leader, communicator, entrepreneur or environmentalist.

Nor is it necessary to be famous: as novelist George Eliot wrote: “The growing good of the world is partly dependent on unhistoric acts; and that things are not so ill with you and me as they might have been, is half owing to the number who lived faithfully a hidden life.”

Robin M. Mills is chief executive of Qamar Energy, and author of The Myth of the Oil Crisis