At a maternity hospital in Beijing, a high-pitched cry announces the start of a new life. Soon, the parents are cradling their newborn baby, tears of joy running down their cheeks. 

But sights like this are becoming rare in China. Experts predict that for the first time since the Great FamineBetween 15 and 55 million people died in a famine in China between 1959 and 1961.  struck 60 years ago, the nation's population will shrink this year. Across the country, cots are lying empty and playgrounds sit abandoned. 

The reason? After four extraordinary decades of population growth, the fertility rate in China is falling fast. In the late 1980s, the average number of births per woman was 2.6. By 2021, it was 1.15, well below the replacement rateThe rate of births needed for babies to replace their parents.  of 2.1. If the trend continues, by 2100 China's population will have fallen by more than half.

The world's biggest country, suddenly without any children? It sounds unlikely. But researchers point out that China is simply following a global pattern. 

Fertility rates are tumbling around the world. The latest census for England and Wales shows that the number of under-fives plummeted by 7.6% in the last decade. In 2021, Italy's birth rate fell to a 160-year low. The shift even prompted one New York Times article to declare "the end of babies".  

World leaders are worried. The number of babies is falling, but the number of elderly people is rising. By 2100, 100 working-age adults will have to support as many as 120 elderly citizens in China. The bill for healthcare and pensions will be astronomical. 

Even celebrities are weighing in. "Doing my bit to help the underpopulation crisis," tweeted Elon Musk last Thursday, apparently confirming the birth of his eighth and ninth children. 

Musk is a rarity. But why are so few people having children? National circumstances play a role: gender inequality in South Korea, anti-family policyUS employers are not obligated to give paid maternity leave to their workers. The Family and Medical Leave Act requires that US employers with 50 or more employees allow mothers to take up to 12 weeks off, but not necessarily with pay. in the USA or strict Covid-19 rules and a lack of women in China. 

There are global trends too. People everywhere are working longer hours for lower wages, leaving them without the time or money to raise a family. The oncoming climate crisis makes us fear that future generations will endure disaster. 

Those who do want children are waiting longerIn Switzerland, Japan, Spain, Italy and South Korea, the average age of first birth for a mother is 31., often until it is too late. In Denmark, assisted reproduction methods now account for roughly one in 10 births.

Perhaps most worrying of all, scientists now think that chemicalsStudies have shown that endocrine disruptors can affect oestrogen levels in women, and sperm production in men. found in many food and consumer products could be damaging fertility in both sexes.

Governments worldwide are racing to reverse the statistics. China has switched from a one-child to a three-child policyChina officially ended its one-child policy in 2016. Today, couples are encouraged to have three children. . Some campaigns have missed the mark: a Copenhagen billboard reading "have you counted your eggs today?" prompted outrage among Danes in 2015. Other tactics, such as a tax on the child-free, as suggested by one demographer last week, would likely be unpopular. 

But some experts warn that their success is critical. If the maternity wards stay empty, we could walk head first into a population crisis. 

Yes: An ageing population is a worry for the whole world. We all want someone to look after us when we get old - but soon there might be no young people left to do so. Babies are a scarce resource.

No: In Niger, the average woman still has 6.8 children. In Somalia, she has exactly six. By 2050, there will likely be 10 billion people on Earth. The world's population is not yet falling.

Or...  It is not all bad, say environmentalists. The planet cannot cope with too many babies. And having fewer babies may allow more women to access education and well-paid careers.

Great Famine - Between 15 and 55 million people died in a famine in China between 1959 and 1961. 

Replacement rate - The rate of births needed for babies to replace their parents. 

Anti-family policy - US employers are not obligated to give paid maternity leave to their workers. The Family and Medical Leave Act requires that US employers with 50 or more employees allow mothers to take up to 12 weeks off, but not necessarily with pay.

Waiting longer - In Switzerland, Japan, Spain, Italy and South Korea, the average age of first birth for a mother is 31.

Chemicals - Studies have shown that endocrine disruptors can affect oestrogen levels in women, and sperm production in men.

Three-child policy - China officially ended its one-child policy in 2016. Today, couples are encouraged to have three children.