Rush hour in Mbagala, in Dar es Salaam, Tanzania, throws the quarter into a frenzy. Buses spill over with commuters at the intercity stop and crowds fill the streets, drawn along a line of vendors, under gazebos bunched up side by side, selling clothes, fruit and vegetables, shoes and grilled chicken. The sound of blaring horns and sellers’ cries fill the air, drowned out by loudspeaker warnings from the authorities prohibiting vendors from peddling their wares on the roadside. Mbagala is a hotspot for small traders. But even as they reap the benefits of the crowds of commuters passing through the neighbourhood each day, vendors say the area is facing growing congestion, rising petty crime and increased environmental waste. As the global population reaches 8 billion on Tuesday, the effects of Tanzania’s rapid growth are evident. The population has increased by 37% over the past decade to almost 63 million according to the latest UN figures, and, projections suggest, is expected to grow between 2% and 3% a year until 2050. Tanzania will be one of eight countries responsible for more than half of the increase in global population over the next three decades: five of those countries will be in Africa. According to UN projections, sub-Saharan Africa’s population will nearly double to more than 2 billion by mid-century. The region is growing three times faster than the global average and, by 2070, it will become the most populous place globally, surpassing Asia. Africa has the youngest population in the world, which experts suggest could be a boon for the continent, or worsen poverty, depending how countries leverage this age group for economic growth. Dar es Salaam, the former Tanzanian capital, is one of the world’s fastest growing cities, and the number of people in the economic hub is expected to double by 2050 to more than 10 million, ranking it alongside such megacities as Kinshasa in the Democratic Republic of the Congo, Lagos in Nigeria and Cairo in Egypt. The country’s leaders have raised alarm at the numbers. Last month, the president, Samia Suluhu Hassan, called for better family planning, saying the high number of births will put pressure on education, healthcare and food. Dar es Salaam residents are already feeling the strain. They have had weeks of water rationing due to a drought – a situation authorities have described as “beyond the control of the government”. A number of the city’s hospitals and schools already work at capacity and are underserved. On top of that, parts of the east African country are struggling with food shortages. Hassan’s predecessor, John Magufuli, who died in 2021, had discouraged the use of contraceptives, saying Tanzania needed more people. Anyone who used family planning was “lazy”, and chided for being afraid of “[working] hard to feed a large family”. The former president implemented decades-long policies that barred young mothers from returning to school after pregnancy. For years, Magufuli suspended significant donor funding for family planning. “Family planning was not appreciated for that period of time,” said Suzana Mkanzabi, executive director of Umati, a sexual and reproductive health rights organisation, adding that support for family planning has improved significantly under the new administration. But Magufuli’s policies will have a long-term impact. UN data shows that most population growth in the next 30 years will be driven by the momentum of the past. Current efforts to manage population growth will only be felt after 2050. Tanzanian women have an average of four or five children – the global average is two. Larger families are culturally valued, and among poorer families, children provide security in old age in a country with few social protections. But with nearly half of the population under 15 or above 65, Tanzania is grappling with high dependency rates. It has fewer tax-paying citizens, and with a significant part of its population dependent on the other, economic mobility is difficult and many poorer residents struggle to get by. Esther Stephano Orio, 34, a mother of five from Dar es Salaam’s Temeke district, says that if she had had better knowledge of birth control, she would have chosen to give birth later. Tanzania has high teen pregnancy and maternal death rates. Abortion is restrictive, and rights groups say backstreet terminations are common. “The country’s policy is still very conservative,” says Mkanzabi, though Umati offers post-abortion care. “It’s high time that the government weighs the pros and cons of whether [abortion] is necessary.” For Orio, becoming a mother at 20 meant career sacrifices; going into teaching instead of nursing, as she feared the working hours would have been too demanding while raising children. The UN cites rapid population growth as a “cause” and “consequence” of slow progress in development. The low use of modern contraceptives is influenced by poor education, a conservative culture that discourages sex education, misinformation about birth control’s effects on fertility, and patriarchal environments, which give male partners significant influence over decisions about contraception. Ideally, Orio would have liked three or four children, but her husband wanted a larger family and they were trying for a boy. While she and her husband, who runs a business, are able to take care of their children, they’ve had to make difficult compromises, like sending only two of them to private schools, which are considered better quality. Among younger generations, demand for contraceptives is higher, says Sheila Macharia, east Africa lead of FP2030, a global family planning partnership, adding that while younger women still have fairly large families, they will use contraceptives to delay births for economic, health and career reasons. Urban women have fewer children than their rural counterparts. As Tanzania grapples with its population spike, family planning will probably become a higher priority for the government. It currently spends only about 14bn shillings (£5m) on birth control each year, relying on dwindling donor resources to fill the gap. The government has pledged to increase that amount by 10% a year by 2030. Rights groups say that much more needs to be done.