Less than 4% of the world's population are international migrants

The HIV epidemic — which started in the early 1980s and progressed rapidly in the 1990s — has had lasting impacts that continue today. More than 800,000 people still die from HIV/AIDS every year.

But some countries were hit much harder than others.

In the chart, you can see the share of all deaths in a given year caused by HIV/AIDS in four countries that were particularly badly affected.

At the height of the epidemic, more than half of all deaths in Zimbabwe and Botswana, and over 40% in South Africa and Namibia, were caused by the disease.

Thankfully, interventions to prevent the spread of HIV and treatments such as antiretroviral therapy have reduced death rates across the world. But about one in five deaths in these countries was still caused by AIDS in 2023.

Religious compositions vary a lot from country to country.

In my own country, the United Kingdom, Christianity is the most popular, and following no religion is becoming increasingly common, particularly among young people. But I struggle to get a sense of how these differences stack up globally.

The Pew Research Center publishes estimates of religious affiliation across the world. You can see the global breakdown in the chart for 2020 (the most recent year available). It shows the number of people who identify with each religion. Pew counts people by the religion they report, regardless of their beliefs or practices.

You can see that Christians are the largest group, with 2.3 billion people, followed by Muslims, with 2 billion. People with no religious affiliation come close behind.

Those not affiliated with any religion are among the largest groups in the world. But this undersells religion’s reach: when we add up all religious groups, most people in the world — around three in four — identify with a religion. Those with no religious affiliation are still a minority.

According to the latest data from the World Health Organization, the global death rate from malaria has almost halved since the year 2000.

The chart above puts this recent progress into a larger historical perspective. It combines the latest estimates from the WHO and the Institute for Health Metrics and Evaluation with those for the 20th century published by the late malaria researcher Richard Carter. Since 1900, the global death rate has declined by 96%. If it were still as high as it was then, around 16 million people would die from malaria every year instead of 610,000.

Behind this long-run decline is a shift in the distribution of the burden of malaria. In the first half of the 20th century, most malaria victims died in the Asian tropics. It was the substantial progress there — as well as in the Mediterranean and in the Americas — that made this vast improvement in human health possible.

Today, more than 9 out of 10 malaria deaths occur in Africa. This means that the recent progress shown in the chart is, above all, Africa’s progress.

China is often the poster child for rapid reductions in poverty, and for good reason. In the early 1980s, over 90% of its population lived in extreme poverty, but by the early 2020s, that number had dropped to nearly zero.

Some might assume that China is the only reason why global extreme poverty has declined. But that’s wrong: many countries have seen dramatic reductions in poverty, too. Indonesia is one clear example; it’s shown alongside China on the chart.

In 1984, 86% of Indonesians lived on less than $3 per day. By 2025, this had fallen to less than 4%. While it didn’t quite match China’s decline, it has still been impressive. The number of people living in extreme poverty has fallen from 140 million to about 10 million.

Note that the international poverty line is extremely low, defined as people living on less than $3 per day. But Indonesia has also made progress when measuring higher poverty lines.

Many of us will have seen the stark images of plastic in the ocean: bottles and wrappers clumped together, or rubbish trapped along the coastline. But how much of the world’s plastic waste ends up in the ocean?

In 2020, Gapminder asked people in Sweden, Norway, Finland, Denmark, and the UK this question. They had three options to choose from:

• A) Less than 1%
• B) Less than 36%
• C) Less than 66%

Almost nine in ten people picked B or C, thinking it was more than one-third.

The correct answer was A: around 0.5% of plastic waste ends up in the ocean.

The chart shows how the OECD gets to this number. Globally, we produce around 350 million tonnes of plastic waste a year. Most of this is managed responsibly, either in secure landfills, through recycling, or incineration. But around one-quarter of it is mismanaged or littered.

From there, a decreasing fraction of plastic waste leaks to the environment, then into rivers and coastlines, and finally into the ocean. Around 1.7 million tonnes end up there: around 0.5% of what was generated in the first place.

People tend to think that most of our plastic ends up there, but only a tiny percentage does. This should make plastic pollution an easier problem to solve: we already know how to manage most of it well. The challenge is to ensure that all plastic is handled this way.

The new Living Planet Index report has just been published. It estimates an average decline of 73% in studied wildlife populations since 1970. You can see this in the chart.

Every two years, it hits the headlines, and I always have mixed feelings about it.

I love that biodiversity loss gets its rare spot in the limelight. It’s a problem that I think doesn’t get enough attention. The trouble is that journalists often report it incorrectly: either as the number of animals or wildlife lost, the number of species in decline, or the number that have gone extinct.

But it tells us none of that.

It examines changes across nearly 36,000 animal populations and reports the average change. This gets even more complicated because it’s based on a geometric mean, and populations get weighted differently in the final index.

When we look a bit deeper, we see that not all populations are doing poorly. As shown in the chart, around half have declined, while the other half have either increased in abundance or remained stable.

As I explained in a previous article, being able to identify which of these populations is doing particularly badly is crucial if we’re to focus our conservation efforts on where they’re needed most.