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 →

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 →

Stomach cancer is one of the leading causes of cancer deaths globally. It is estimated that around one million people died from it in 2021.

However, most are preventable, and as the chart shows, there has been a substantial decline in age-standardized death rates from stomach cancer over time.

This can be seen in data from the World Health Organization’s Mortality Database, which has recorded causes of death in many countries since the 1950s.

These large declines are the result of improvements in prevention and treatment. For example, screening and treatment have improved for stomach infections by H. pylori, a bacteria that causes stomach ulcers that can develop into cancer.

Additionally, improvements in hygiene, cancer treatments, and surgery, as well as reductions in smoking, have each been important in reducing stomach cancer mortality.

Explore this data for many more countries — we have just updated it →

Aquaculture production — farming fish and other seafood products — has exploded over the last few decades.

Nearly all of this growth has come from East Asia, which you can see in the chart. This is based on estimates from the Food and Agriculture Organization of the United Nations.

In 2021, the world produced 126 million tonnes of seafood from aquaculture. 80% of this came from East Asia and the Pacific.

Explore this data →

This chart shows the share of the global population living in countries that criminally sanction domestic violence or provide protection against it. The data comes from the World Bank’s Women, Business and the Law project.

Throughout the decades, the legislation on domestic violence has increased markedly. Until the 1990s, less than 1% of the global population in countries was legally protected from it, with only Canada, Sweden, and Ireland providing such safeguards. And as recently as 20 years ago, 80% of people lived in countries without legal penalties for domestic violence.

But by 2023, this had more than reversed, and 9 in 10 people lived in countries with legal measures to combat domestic violence. This shift highlights an increased recognition around the world that domestic violence is common, especially against women.

Explore our charts on women's rights →

Child mortality rates in China have fallen from more than 20% in 1950 to less than 1% today.

But this steady progress was interrupted in the late 1950s during the “Great Leap Forward”. This was China’s national plan to industrialize rapidly, but it resulted in widespread famine and economic turmoil.

As the chart shows, child mortality rates spiked in China over this period. This change was so dramatic that it is also clearly visible in the global trend. This data comes from the UN’s World Population Prospects.

Explore this data →

Drug-related death rates have increased six-fold in Canada and the United States over two decades, according to recent data from the World Health Organization’s Global Health Estimates. We have just updated our charts with the latest data.

In 2000, drug-related death rates in Canada and the United States were reasonably similar to rates in other countries. But since then, deaths from drugs, particularly opioids, have risen sharply.

Opioids include prescription painkillers like OxyContin and Vicodin, synthetic opioids like fentanyl, and drugs like heroin.

Over recent years, opioids have become common in the management of chronic pain, and they’ve become much easier to access on the illicit drug market.

Explore data on deaths from drug use and other health issues in our Global Health Explorer →

Skilled health staff can reduce the risk of mothers and infants dying during childbirth.

In most countries, almost all births are now attended by trained health professionals. But as you can see on the map, this is the case for less than half of births in some of the world’s poorest countries.

This is based on data from Demographic and Health Surveys and UNICEF. Note that this doesn’t mean births in these countries aren’t attended by any skilled staff; it simply measures staff with professional medical training.

Improving access to essential healthcare and services could help reduce maternal and infant mortality rates.

Explore the data →

Infancy used to be an extremely dangerous time of life.

As the chart shows, around 20% of girls in Sweden died before their first birthday in the 18th century. This was higher than the risk among 80-year-olds — at that age, 10% to 20% died each year.

Since then, the risk of dying has reduced across all ages, but the reduction has been most profound for infants. Rates have fallen 100-fold.

This progress has come from improvements in hygiene, clean water and sanitation, vaccination, nutrition, neonatal healthcare, and surgery.

The data comes from the Human Mortality Database and the United Nations World Population Prospects. I’ve shown data from Sweden, which has the longest historical records, stretching back to the 1750s.

Explore the same data for many more countries →

According to the Energy Institute’s Statistical Review of World Energy, in 2023, Chile produced 9.4% of its primary energy from solar sources, the highest share in any country. When we look at electricity alone, solar produced 20% of the total.

This marks a trend of continued year-on-year growth in a country that, just a decade earlier, generated almost no electricity from solar.

Chile's growth has been faster than that of other solar champions like Spain and Australia, where the adoption of these technologies started earlier.

Much of Chile's solar energy is captured in the Atacama Desert. This region, in Northern Chile, receives the highest level of sunlight exposure in the world and is home to Latin America’s first solar thermal plant.

Explore data on energy production and sources, country by country →

The chart shows net migration trends for Venezuela, Peru, Chile, and Colombia from 1950 to 2023. This is the net difference between immigrants coming into a country and emigrants leaving. This data published by the UN World Population Prospects shows how significant this demographic event is in the region’s recent history.

Starting around 2015, Venezuela's net migration dropped sharply, with a record 1.36 million people emigrating in 2018. The timing of this shift, accelerating from 2015 onwards, coincides with Venezuela's worsening economic and political instability.

At the same time, wealthier countries like Peru, Chile, and Colombia experienced significant increases in net migration, which suggests they have become major destinations for Venezuelan migrants. This trend is even clearer when visualizing where immigrants from Venezuela moved to.

Explore net migration patterns in other countries →

Unsafe sanitation is responsible for hundreds of thousands of deaths each year. It increases the risk of many fatal diseases, including cholera, diarrhea, dysentery, hepatitis A, typhoid, and polio.

Unfortunately, over 40% of the world does not have access to safe sanitation facilities. This is based on estimates from the WHO/UNICEF’s Joint Monitoring Programme for Water Supply, Sanitation and Hygiene.

The chart shows the share of the global population that has access to safe sanitation over time. While rates have increased, particularly over the last decade, they still fall far short of the UN’s target of universal access in 2030.

Increasing access to safe sanitation would save many lives from preventable infectious diseases.

Explore the data →

The chart shows that in the late 19th and early 20th centuries, governments’ social spending amounted to very little. Countries spent, at most, 1 to 2% of their national income on public social services.

This changed significantly over the 20th century: public social spending in wealthy countries now amounts to between 15% and 30% of national income.

The biggest reasons for this increase are higher expenditure on healthcare and education.

This data comes from the OECD and Peter Lindert’s history of social spending.

Read more about the history of government spending →

The chart shows the death rates from respiratory infections in countries since 1950.

Data comes from the WHO Mortality Database, which compiles data reported by each country. The data typically comes with a few years of delay since it needs to be standardized.

It helps us to look back and see the impact of the COVID-19 pandemic from a historical perspective.

As you can see, there has been a long-run decline in respiratory infection death rates. This is due to improved sanitation, healthcare, and vaccination against diseases such as influenza, tuberculosis, and pertussis.

But during the pandemic, death rates from respiratory infections surged massively due to COVID-19 and reached levels not seen in many decades.

Explore the data on respiratory infection death rates for other countries →

The chart shows how much people rely on rail versus road transport in 2021. The data comes from the OECD, and we recently updated our charts with the latest release.

Japan stands out with 28% of passenger kilometers traveled by rail. This contrasts sharply with New Zealand and the United States, where rail accounts for only 1.4% and 0.25% of passenger kilometers, respectively.

In Western European countries, rail transport is still in the minority, but less so. In France, 10% of passenger kilometers are traveled by rail, 6.4% in Germany, and 5% in the United Kingdom.

Countries with well-developed rail networks and high usage also tend to have lower domestic transport-related CO2 emissions.

Explore passenger kilometers traveled by road and rail in other countries →

Infant mortality rates have plummeted over the last 50 years. Globally, they’ve fallen by over two-thirds, from around 10% in 1974 to less than 3% today.

A recent study — published in The Lancet by Andrew Shattock and an international team of researchers — estimates that increased access to crucial vaccines means that infant mortality rates are 40% lower than they would be in a world without vaccines.

The chart shows the actual reduction in infant mortality rates with vaccination (in blue) and the researchers’ estimates for a hypothetical scenario in which vaccines wouldn’t have been rolled out (in red).

Based on these figures, vaccines are estimated to have saved 150 million children over the last 50 years. Vaccinations accounted for 40% of that decline.

Read our article on the role of vaccination in reducing infant mortality →

The chart shows that the average worker in wealthy countries now works only about half as many hours per year as in the late 19th century.

Based on data from economic historians Michael Huberman and Chris Minns, the average worker used to work between 2,700 and 3,500 hours per year, which is about 50 to 70 hours each week.

Recently, using data from the Penn World Table, workers worked about half that amount, between 1,300 and 1,800 hours a year, or about 25 to 35 hours a week.

This decrease has come from working fewer hours each day, fewer days each week, and fewer weeks each year.

Read more in our article on whether we are working more than ever →

Four decades ago, when HIV was first identified, it was an invariably fatal disease: nearly 100% of those infected died, typically within a few years.

The virus spread rapidly around the world — especially in Africa, where almost two million were dying every year by the millennium.

Thankfully, medical advances and global public health efforts have entirely changed this course. Modern antiretroviral therapy is very effective in both treating HIV — returning people with HIV to near-normal life expectancy — and preventing the virus from spreading to others.

The chart above shows this impact based on data from UNAIDS. Over a million people's lives are now saved by antiretroviral therapy each year.

Recent medical advances could take this progress even further.

Read more on how antiretroviral therapy has changed the lives of people with HIV →

Cereals, roots, and tuber crops — such as cassava or potatoes — are some of the cheapest options for getting enough calories. In poorer countries, people get much of their daily energy from these crops.

The chart shows the share of calories that the average person gets from these staples, measured against gross domestic product (GDP) per capita. This data comes from the Food and Agriculture Organization of the United Nations and the World Bank.

People in some of the world’s poorest countries get two-thirds to three-quarters of their calories from cereals and other staples, compared to around one-third in the richest countries.

This means those on low incomes have less diverse diets and often miss out on key nutrients from legumes, fruit and vegetables, meat and dairy, and other foods.

Explore the data →

Generative AI is a type of artificial intelligence that can create various media, including text, images, and music. It learns from existing data to generate novel outputs. Examples include language models like GPT-4 and Claude, which can write essays or answer questions, and image generation models like Midjourney and DALL·E, which can create artwork based on textual descriptions.

In 2023, funding for generative AI soared to $22.4 billion, nearly nine times more than in 2022 and about 25 times the amount from 2019. This surge occurred despite overall investment in AI declining since its 2021 peak.

The data is produced by Quid and made available through the AI Index Report. Quid analyzes investment data from over 8 million companies, using natural language processing to uncover patterns and insights from vast datasets. We have recently updated our charts on Our World in Data with the report's latest edition.

Read more on how investment in AI has been changing over time here →