January 15, 2026
In 2021, around 1.25 million people died from diarrheal diseases. Around a third of these deaths were children.
Two main factors explain why so many children still die from diarrhea, especially in poor countries: the persistence of risk factors such as poor sanitation and unsafe water, and the lack of access to effective treatment.
Here, I want to focus on the second factor: access to a particularly effective treatment, known as oral rehydration therapy (ORT), which is essentially a mixture of clean water, salts, and sugar. Simple as it may sound, researchers writing in the medical journal The Lancet called ORT “potentially the most important medical advance of the 20th century.”
The chart shows how often this treatment is used in a selection of African countries. This is based on household surveys asking caregivers of children under five who recently had diarrhea whether they received ORT.
There are large gaps: in Chad and Cameroon, fewer than one in five children with diarrhea received the treatment. This reflects a mix of challenges, including low awareness of its benefits and expensive or inconsistent supply.
Importantly, though, the chart also shows that rates are much higher in Sierra Leone, where around 85% of children received ORT. This shows that much higher coverage is possible. Sierra Leone has implemented several successful policies, including free treatment for children.
Not every child with diarrhea needs this treatment — some recover without it, depending on their health and circumstances. But ORT is cheap, safe, and easy to give. In low-income settings, especially, offering it widely as a cheap preventive measure can make a big difference for those who need it.
Today
To decarbonize road transport, the world must move away from petrol and diesel cars towards electric vehicles and other forms of low-carbon transport.
This transition has already started. In fact, global sales of combustion engine cars are well past their peak and are now falling.
As you can see in the chart, global sales peaked in 2017. This is calculated based on data from the International Energy Agency. Bloomberg New Energy Finance also estimated this peak occurred around that time.
Sales of electric cars, on the other hand, are growing quickly. They more than doubled in the three years from 2022 to 2025.
May 19
In Tajikistan, remittances — the money sent or brought back by migrants — amounted to 48% of GDP in 2024. The chart places this figure in context by comparing it with other countries with data for the same year.
Nicaragua and Honduras receive remittances worth around a quarter of their GDP — high by global standards, but still far below Tajikistan's level.
Remittances here include two types of flows: money migrants abroad send home to their families, and money cross-border workers bring home from short-term jobs abroad.
Both of these flows play a role in Tajikistan, where most remittances come from labor migrants in Russia. In addition to the roughly 400,000 Tajiks settled there, hundreds of thousands more cross the border for seasonal and short-term work.
According to a report from the International Organization for Migration, about 1.2 million Tajiks were in Russia in mid-2024, which is more than a tenth of Tajikistan's total population.
The World Bank's latest Tajikistan Economic Update says that much of the country's recent rapid economic growth (above 8% since 2021) was supported by these remittance inflows.
May 16
We’ll often see headlines quoting how many gigawatts of new solar farms or coal plants China is building. But it’s hard to get a meaningful sense of scale for how electricity generation in China is changing.
The chart puts it in perspective.
In 2025 alone, China’s electricity generation increased by almost 500 terawatt-hours (TWh). This is compared here to the total amount of electricity that whole countries generate each year.
Germany generates almost exactly that amount. That means China effectively added a Germany-sized grid to its electricity system in just one year.
What’s also quite staggering is that almost all of this new generation came from solar and wind. China generated 340 TWh more electricity from solar than the year before.
That’s more than our two home countries, the UK and Spain, generate from all sources each year.
Low-carbon sources grew so much that coal power in China actually fell slightly.
May 14
Japan closed down most of its nuclear plants after the Fukushima Daiichi disaster in 2011, and nuclear production dropped dramatically.
You can see this in the chart above, which shows Japan's electricity mix since 1985. It’s based on data from the Energy Institute.
Fossil fuel plants — notably coal and gas — were ramped up to keep the lights on. The first nuclear reactors only came back online in 2015, under stricter rules from a new safety regulator created after the disaster.
As of early 2026, 15 reactors are running — out of 54 before Fukushima — and nuclear's share of electricity is still only around a third of its pre-2011 level.
May 12
Crop yields across Africa have lagged far behind the rest of the world — the regional average is around 2.5 times lower than the global average.
But some countries in the region show that yields can grow much faster. Ghana is one example. In the chart, you can see its cereal yields compared to the average for Africa as a whole.
Several government programs contributed to this growth.
In 2008, the Ghanaian government launched a fertilizer subsidy program; it had some impact on yields but was relatively modest.
The largest shift came from the introduction of the Planting for Food and Jobs program in 2017, which dedicated large public funds to distributing improved seeds, fertilizers, and other inputs to farmers.
The data shown is based on nationally reported statistics, and some researchers question the exact size of the reported gains.
But the result that yields have gone up looks robust: independent modeled assessments estimate that maize and rice production are over 40% higher than they would have been without the program.
May 9
In the late 20th century, a handful of countries — led by Brazil and the United States — turned to liquid biofuels to reduce their dependence on foreign oil markets, producing transport fuels from cheap crops instead.
In the early 2000s, interest in biofuels ramped up sharply, and not just in the Americas. They came to be seen as a leading method to decarbonize road transport. This was because today’s alternative to the combustion engine, the electric car, was still far too expensive.
Over the last two decades, global liquid biofuel production has grown sevenfold, as the chart shows.
Electric vehicles are now far cheaper and, in some places, cost-competitive with petrol cars, so biofuels are no longer seen as the central answer to low-carbon transport.
Yet, the world produces more of them than ever, and this is expected to grow over the coming decade, largely due to fuel standards and national policies that have promoted them.
May 7
Around 1.3 million people die from road injuries across the world every year. That includes the deaths of drivers, passengers, and pedestrians.
That’s around 2.4% of deaths from all causes.
As the chart shows, this death toll has been similar for decades, in the range of 1.25 to 1.35 million deaths each year.
However, with a larger global population and many more cars on the road, this means the death rate from road injuries — the number of deaths per 100,000 people — has fallen.
