June 12, 2024
In the last two centuries, the price of lighting has decreased drastically.
You can see this in the chart, which plots historical data from Roger Fouquet and Peter Pearson. To allow for comparisons over time, the data is adjusted for inflation and expressed in prices for the year 2000.
In the 1300s, one million lumen-hours — a standard lighting measure — would have cost around £40,800 in 2000 prices. By 2006, this had fallen to £2.90, a 14,000-fold decline.
Innovations in lighting appliances, fuels, infrastructures, and institutions during the 19th and 20th centuries made this progress possible.
To put this in perspective, consider that a standard 100-watt incandescent light bulb today can emit about 1,700 lumens. Therefore, running one such bulb for 24 hours would produce about 50,000 lumen-hours. That means that 1 million lumen-hours today would require continuously keeping a standard 100-watt incandescent bulb on for about 25 days. Achieving the same amount of light with candles would require burning more than 100 candles every day for that period.
Most people today take the ability to switch on a light at night for granted. But those who live or have lived without artificial light can appreciate how important it is.
Today
Homicide rates in Brazil are among some of the highest in the world, and young people are more likely to be victims.
Another large killer of young people is road injuries. But in Brazil, the number of homicide deaths among young people is twice as high as that of road fatalities.
You can see this in the chart: an estimated 48,000 people aged 15 to 49 years died by homicide in 2021 — almost double the 25,000 who died from road injuries.
These comparisons are based on data from the IHME’s Global Burden of Disease study. Note that estimates of homicides can vary by source, as explained by my colleagues Bastian Herre and Fiona Spooner.
Explore more data on homicide rates across the world, including comparisons of different sources →
March 28
The world needs to move away from fossil fuels to low-carbon power if we’re to reduce our carbon emissions and tackle climate change.
There are two key sources of low-carbon power: renewables (which include solar, wind, hydropower and others) and nuclear.
While rapid growth in solar and wind has increased the amount of power coming from renewables, a lack of enthusiasm for nuclear means it’s playing a shrinking role in the global electricity mix.
In the chart, you can see the share of global electricity coming from fossil fuels, renewables, and nuclear since 1985. Since 2000, nuclear and renewables have followed very different trajectories. Back then, both categories made up a similar share of global electricity, but today, renewables make up more than three times as much: 30% compared to 9%.
The total amount of electricity produced by nuclear plants is almost exactly the same as it was two decades ago. But because the world produces much more electricity overall, its share of the electricity mix has declined.
Explore the electricity mix of different countries in our Energy Data Explorer →
March 27
The HIV epidemic — which started in the early 1980s and continued into the 1990s — has had lasting impacts that continue today. Almost one million people still die from HIV/AIDS every year globally.
However, some countries were hit much harder than others.
In the chart, you can see the share of all deaths in a given year that were caused by HIV/AIDS in four countries in Sub-Saharan Africa that were badly affected.
At the height of the epidemic, more than half of all deaths in Zimbabwe and Botswana and almost 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 more than one in ten deaths in these countries are still caused by AIDS today.
Read our article on antiretroviral therapy and the millions of lives it has saved →
March 26
In 2008, Bhutan started measuring the “Gross Happiness Index” as an official metric to track the well-being of its population. As a result, it’s often coined the “Land” or “Kingdom of Happiness”.
Bhutan tracks gross happiness with in-depth surveys, which other countries do not. How does it compare across similar metrics where we can make these comparisons? Despite its reputation, it’s actually not an outlier.
Self-reported life satisfaction is one internationally comparable metric measured in the annual World Happiness Report. Respondents in every country are asked to rate their lives based on a 10-step ladder, where 0 represents the worst possible life, and 10 is the best.
Self-reported life satisfaction tends to be higher in richer countries, although there is a spread among countries with similar gross domestic product (GDP) per capita. The chart plots one against the other.
For its income level, Bhutan has a fairly average life satisfaction score; in the global comparison, it’s about as happy as we would expect based on the incomes of people in the country.
Explore more data on levels of happiness across the world →
March 25
For many decades, most children in Europe were born to mothers in their twenties. However, since the mid-1970s, there has been a steady increase in the number of women giving birth in their thirties.
As the chart shows, since 2015, women in their thirties have given birth to the greatest number of babies; in the same year, it became more common for a woman in her forties to give birth than for women in their teens.
Many factors are causing these changes, including women spending more years in education and developing their careers, easily accessible contraception, improvements in fertility treatment, and high childcare costs.
Explore at what age women are having children in your country →
March 24
Antibiotics can play an important role in preventing disease and improving the health of animals. But overusing them, particularly for livestock, poses a risk to human health through antibiotic resistance.
Over the last decade, Europe has made much progress in reducing antibiotic use in farm animals. This has been achieved through stricter regulations and, in some countries, taxes on antibiotics.
The chart shows the change in sales of these antimicrobials for livestock between 2010 and 2022. It shows a range of European countries, with a few examples highlighted in bold.
Antibiotic use has fallen by over half in some countries, such as the UK, Italy, France, and the Netherlands.
These countries have still managed to maintain productive agricultural sectors by focusing on other ways to manage disease risk and animal growth, such as vaccinations, ventilation, cleaner equipment, and high-quality diets.
Read more about the differences in antibiotic use for livestock across the world →
March 21
January 2025 was the hottest January on record. This was surprising because the world recently transitioned from El Niño (which tends to increase global temperatures) to La Niña (which tends to cool them). We might have expected this cooling to be reflected in January’s temperatures. It was not.
But February did not follow this same pattern.
The chart tracks monthly temperature anomalies, comparing current temperatures to historical averages. Each dot represents a February anomaly, with El Niño (warmer) years in orange and red and La Niña (cooler) years in blue.
As expected, February 2025 cooled compared to February 2024, following the usual pattern where La Niña years tend to be cooler than the El Niño years before them.
However, this doesn’t mean global warming has slowed. Recent La Niña years are still warmer than El Niño years from just a few decades ago, showing that even natural climate fluctuations don’t reverse the long-term warming trend.
We update this data monthly so you can track how these patterns evolve.
Read our recent article that explains in more detail how the world is warming despite natural fluctuations from the El Niño cycle →
