August 27, 2024
Exoplanets are planets that orbit stars other than the Sun. Their existence was first confirmed in 1992 when astronomers Aleksander Wolszczan and Dale Frail identified two exoplanets orbiting a star located 2,300 light-years from Earth.
As shown in this chart, from 1992 to 2005, scientists discovered two hundred more exoplanets. They primarily used a method called "radial velocity". This technique works by detecting small changes in the color of a star due to the gravitational pull of a planet orbiting it.
But starting in the mid-2000s, the "transit method” vastly accelerated the pace of exoplanet discovery. This method detects tiny dips in a star’s brightness when a planet passes in front of it. This dimming can reveal a planet's presence and provide information about its size and orbit.
As is often the case with technological change, what was once a unique scientific achievement has become a much more frequent occurrence. The advancements in detection methods now allow us to discover hundreds of exoplanets each year.
Adding up all methods of identification, more than 5,500 exoplanets have been found by scientists worldwide, according to data from NASA's Exoplanet Archive.
Today
The chart shows how incomes are spread in several countries in different world regions. The data comes from the excellent Luxembourg Income Study.
Blue points show the monthly after-tax income of someone who falls just inside the richest 10% of their country's population. Red points show the income of someone who falls just inside the poorest 10%. To allow for comparisons, all incomes are shown in international dollars, which account for differences in cost of living across countries.
The ratio between these two numbers gives us a measure of inequality known as the “P90/P10 ratio”.
In Norway, a country with very low inequality, this ratio is around 3. A person just inside the richest 10% has a monthly income of $5,490 — a little more than 3 times the $1,760 earned by someone just inside the poorest 10%.
In the United States, inequality is much higher, and the ratio is twice as large — around 6. The chart shows that the richest 10% are much richer than those in Norway, with incomes above $7,440. But, the poorest are also poorer, with incomes of less than $1,240.
In many countries, the ratio is between 4 and 6. But in the most unequal countries, it is much higher. In South Africa, the ratio is 22. Those in the bottom decile are among the poorest people in the world, living on less than $110 per month. In contrast, the richest 10% earn $2,490 or above — higher than the incomes of half the UK population and nearly a third of the US population.
Explore incomes across the distribution for other countries in our dedicated Data Explorer →
Yesterday
Cobalt is a critical element in many lithium-ion battery technologies, which are used in most consumer electronics such as mobile phones and laptops; and more recently, in electric vehicles.
Almost three-quarters of the world’s cobalt is mined in the Democratic Republic of Congo (DRC).
However, the DRC produces virtually none of the world’s refined cobalt — the mineral used in final products. Most of the world’s refined cobalt is made in China.
You can see this in the chart above, which shows each country’s share of global mined and refined cobalt production in 2021. This data comes from the US Geological Survey (USGS) and British Geological Survey (BGS).
While lithium-ion battery technologies that use cobalt are dominant today, alternative battery chemistries that don’t use cobalt are emerging.
Explore more data on which countries produce the world’s critical minerals →
October 01
Most electoral democracies are younger than the oldest people who live in them.
The chart shows that almost two dozen democracies are younger than 18 — as young as the children in these countries. Others are only as old as their young adults. This is based on data from Regimes of the World.
In these younger democracies, most people have experienced life under authoritarian rule, and older people lacked democratic political rights for most of their lives.
A larger group of countries have been electoral democracies for one to three generations. In these countries, children and young adults have only known life in a democracy, but their parents and grandparents have experienced non-democratic rule.
Only ten countries have been democratic for more than 90 years. In these places, democracy is older than almost all of their citizens.
Read more in our article on the age of democracies →
September 30
Obesity rates have increased across the world over the last 50 years, but at varying speeds and from different starting positions.
The chart shows the change in the share of adults who are defined as “overweight” or “obese” across a range of countries. It is based on the latest data from the World Health Organization (which only goes up to 2016).
Rates have increased worldwide — from Australia and the United States to India and Nigeria — but tend to be higher in richer countries where food supplies are more plentiful and affordable for the population.
This is measured based on body mass index (BMI), which takes account of someone’s height and weight. It’s a crude measure, but it gives us quick insights into how people’s metabolic health is changing.
Explore global data on overweight and obesity rates →
September 27
New petrol and diesel cars are becoming a rarity in Norway.
In 2023, 93% of new cars sold in the country were electric. This is shown in the chart, based on data from the International Energy Agency.
This is a rapid increase from a decade ago when just 6% of new cars were electric.
Here, “electric cars” include fully battery-electric and plug-in hybrid cars (which have a smaller battery and also have a combustion engine). But in Norway, battery-electric cars now dominate: in 2023, 85% were fully electric, compared to just 8% of plug-in hybrids.
Explore the data for other countries in our dedicated article →
September 26
This chart shows average temperatures in the 1940s and 2010s compared to the average from 1991-2020. These differences — called temperature anomalies — help us see how temperatures have changed. We source this data from the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA5 project.
Globally, the 1940s were 0.66°C cooler than the 1991-2020 average, while the 2010s were 0.2°C warmer. This means that over about 70 years, the global average temperature increased by approximately 0.86°C. Compared to pre-industrial times, the current global average temperature is estimated to have risen by approximately 1.3°C.
Ireland is the only country where temperatures in the 1940s were similar to the 2010s.
Every other country has seen temperatures increase over this period, with some experiencing more than several degrees of warming.
This illustrates how local climate variations can differ from global trends. The effects can vary from place to place, but global warming remains a broad phenomenon.
Explore decadal temperature anomalies in other countries →
September 25
Lead exposure has fallen dramatically in the United States over the last 50 years.
Despite being toxic to human health, lead was used in various products, including gasoline, paint, and pipes. However, there have been successful efforts to phase it out in recent decades.
The chart shows measurements of lead concentrations in children’s blood since the late 1970s, based on data from the US Center for Disease Control and Prevention and the National Center for Health Statistics. Both the average child and those with the highest exposure rates — the 95th percentile — show a dramatic decline.
Lead exposure is still a massive problem in many low-to-middle-income countries, where its use in paints, pipes, and other sectors is not monitored or controlled.
Read more in our article on the decline of lead poisoning →
