November 27, 2025
The 1970s were a decade shaped by fears about overpopulation. As the world’s most populous country, China was never far from the debate. In 1979, China designed its one-child policy, which was rolled out nationally from 1980 to curb population growth by limiting couples to having just one child.
By this point, China’s fertility rate — the number of children per woman — had already fallen quickly in the early 1970s, as you can see in the chart.
While China’s one-child policy restricted many families, there were exceptions to the rule. Enforcement differed widely by province and between urban and rural areas. Many couples were allowed to have another baby if their first was a girl. Other couples paid a fine for having more than one. As a result, fertility rates never dropped close to one.
In the last few years, despite the end of the one-child policy in 2016 and the government encouraging larger families, fertility rates have dropped to one. The fall in fertility today is driven less by policy and more by social and economic changes.
This chart shows the total fertility rate, which is also affected by women delaying when they have children. Cohort fertility tells us how many children the average woman will actually have over her lifetime. In China, this cohort figure is likely higher than one, but still low enough that the population will continue to shrink.
Today
Most of the world's poorest people still rely on solid fuels — such as crop waste, dung, wood, and charcoal — for cooking and heating.
These fuels generate household air pollution when they’re burned. This has health impacts for those who breathe them in, and can increase the risk of a range of illnesses, including cardiovascular disease, stroke and some cancers.
Estimates from the Institute for Health Metrics and Evaluation suggest that indoor air pollution causes almost three million premature deaths each year. That’s three million people dying earlier than they otherwise would without this pollution.
As shown on the chart, deaths from indoor pollution have fallen as more people get access to cleaner cooking fuels. Improving access to clean energy could prevent many more early deaths.
April 18
Cervical cancer death rates among women in the United Kingdom have fallen by around 80% since 1950. You can see this reduction in the chart.
This progress happened for a couple of key reasons.
The first was the introduction of population-level screening programs in 1988. Across the UK, women are invited to get a regular smear test to detect precancerous changes or cervical cancer cases early, when treatment has much better odds of success.
Another, and more recent innovation, which could put the UK on the path to eradicating cervical cancer completely, is the rollout of the human papillomavirus (HPV) vaccine. This protects someone from the HPV infection, which can later develop into cervical cancer.
In schools across the country, girls in their early teens are offered the HPV vaccine, effectively offering them long-lasting protection. I was one of the first cohorts of girls in the UK to receive this, and it’s something I’m incredibly grateful for.
The UK is not alone in its progress: a number of countries have managed to reduce cervical cancer death rates in recent decades.
April 16
France generates two-thirds of its electricity from nuclear power, making it the country’s dominant power source.
As the chart shows, that’s far more than the average across Europe, which is 20%, and the world as a whole, at 9%.
Nuclear power is a low-carbon electricity source, giving France a very clean electricity mix for decades.
Per unit of electricity, France emits far less greenhouse gas than its neighbors and has some of the lowest-carbon power in the world. The global average, based on lifecycle emissions, is 472 grams of carbon dioxide equivalents (CO2e) per kilowatt-hour of electricity generated. In France, this figure is 42 grams.
April 14
In every region of Africa, hunger is more prevalent than a decade ago.
The chart shows the increase in the share of the population that is undernourished, comparing 2014 and 2024 (the most recent year available). These estimates come from the Food and Agriculture Organization of the United Nations.
The situation across Africa is dire. In Middle Africa, where hunger is most acute, almost 1 in 3 people are undernourished. In Eastern Africa, the figure is roughly 1 in 4. Across Africa as a whole, it's 1 in 5.
This marks a reversal of a longer positive trend: over the preceding decades, hunger had been falling across much of the world, including parts of Africa. That progress has now stalled or gone into reverse. Conflict, extreme weather, and the economic disruption of the COVID-19 pandemic have all contributed.
April 11
The concept of “leapfrogging” is popular in development. It suggests that, as they develop, lower-income countries can skip intermediate technologies or systems and go straight to the modern equivalent.
One example of this is the use of landlines and mobile phones.
The landline telephone was invented in 1876 and became a dominant form of communication across Europe and North America. As you can see in the chart, it was increasingly adopted in the United States and the United Kingdom throughout the 20th century.
However, mobile phone adoption increased rapidly in the 1990s, and landlines have declined since the millennium. Mobile phones have become a substitute.
But many countries have almost skipped landline adoption entirely. Ghana and Nigeria are good examples: landline subscriptions have remained extremely low, and instead, mobile phone adoption has exploded.
April 9
Even after years of working with global health data, one statistic that I’m always struck by is the number of people who die by suicide every year. In 2023, it was estimated to be around three-quarters of a million.
That means suicides account for more than 1 in every 100 deaths in the world.
But a world where so many die from suicide is not inevitable. We know this because global suicide rates have fallen by an estimated 40% since the 1990s.
You can see this in the chart: rates have fallen from 15 to 9 deaths per 100,000 people over the last thirty years.
The large differences between countries also suggest that there are things that can be done to reduce this number even further.
April 7
Some technologies central to the clean energy transition depend on rare earth elements. The permanent magnets found in many electric vehicle motors and wind turbine generators rely on them. They are also used in some military hardware.
China dominates global production of rare earths; in 2024, it accounted for nearly 70% of the global total.
But the picture is not as concentrated when you examine which countries have rare-earth reserves. That is what the chart shows, plotting production and reserve shares side by side. China still holds the most known reserves, but at 49%, this is substantially lower than its production share.
Brazil holds 23% of reserves and is barely mining them. India, Vietnam, and Russia also hold significant reserves, but only a small fraction of current output.
The large gap between where reserves are located and where mining occurs partly reflects China's early investment in mining infrastructure and processing capacity, which other producers have not yet matched. Other countries hold the geological potential but have not yet developed the infrastructure to convert it into production at scale.
