What is the ozone layer, and why is it important?
Over the last 50 years, holes in the ozone layer have opened up. Why does that matter for life on Earth?
March 13, 2023
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Latest
Our latest articles, data updates, and announcements
February 28, 2023
Article
Our World in Data will rely on data from the WHO to track confirmed COVID-19 cases and deaths
Johns Hopkins University will stop publishing data on confirmed COVID-19 cases and deaths. Our team will replace our entire time series with WHO's data on 8 March 2023.
February 27, 2023
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How we choose which topics to work on, and which metrics to provide
On Our World in Data, we present thousands of metrics on hundreds of topics. How do we choose them?
February 22, 2023
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Technology over the long run: zoom out to see how dramatically the world can change within a lifetime
It is easy to underestimate the magnitude of this change. Understanding this can help us see how different the world could be in the future.
February 20, 2023
Article
What does it mean for a species to be at risk of extinction?
We need to focus on the most threatened species to protect them from extinction. But what does it mean for a species to be at risk, and how is it measured?
February 7, 2023
Article
AI timelines: What do experts in artificial intelligence expect for the future?
Many believe there is a real chance that human-level AI will be developed within the next decades, and some believe that it will exist much sooner.
January 19, 2023
Article
Engel's Law: Richer people spend more money on food, but it makes up a smaller share of their income
How does spending on food change as incomes rise?
January 5, 2023
Article
How many people die and how many are born each year?
Changes in the world population are determined by two metrics: the number of babies born and the number of people dying.
December 15, 2022
Article
Artificial intelligence is transforming our world — it is on all of us to make sure that it goes well
How AI gets built is currently decided by a small group of technologists. It should be in all of our interest to become informed and engaged.
December 6, 2022
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The brief history of artificial intelligence: the world has changed fast — what might be next?
Little is as important for the world’s future and our own lives as how this history continues.
November 30, 2022
Article
There have been five mass extinctions in Earth's history
When did the "Big Five" mass extinctions happen, and what were their causes?
November 30, 2022
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How many species are there?
How many species do we share our planet with? How many of these species have we found and identified?
November 30, 2022
Article
Did humans cause the Quaternary megafauna extinction?
10,000 to 50,000 years ago, hundreds of the largest mammals went extinct. It's likely that humans were the key driver of this.
November 30, 2022
Article
Global whaling peaked in the 1960s
Intense whaling drove many of the world’s whale species close to extinction. But a dramatic decline in whale hunting since then has given them hopes of recovery.
November 30, 2022
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The state of the world's rhino populations
How have rhino populations changed over time? What species are at risk of extinction today?
October 26, 2022
Article
From $1.90 to $2.15 a day: the updated International Poverty Line
The World Bank has updated the methods it uses to measure incomes and poverty around the world. What does this mean for our understanding of global poverty?
October 20, 2022
Article
How many people die from the flu?
The risk of death from influenza has declined over time, but globally, hundreds of thousands of people still die from the disease each year.
October 18, 2022
Article
Introducing our updated work on Poverty: a new design for our content
We’ve just published a major redesign of our topic pages. Explore this redesign with our new work on poverty.
October 14, 2022
Article
Which countries have put a price on carbon?
Putting a price on carbon helps us account for the real costs of fossil fuels in the market. Which countries have a carbon tax or trading system?
October 13, 2022
Article
FAQs on the Living Planet Index
The Living Planet Index is one of the most common measures used in biodiversity monitoring. But what is it, and where does this data come from?
October 13, 2022
Article
How does the Living Planet Index vary by region?
The Living Planet Index shows an average decline of 73% across studied animal populations globally. But how does this vary by region?