February 07, 2025
To mitigate the negative impacts of climate change, the world needs to quickly transition from fossil fuels to low-carbon energy sources such as solar power.
The chart shows how much this transition has accelerated in the last two decades.
In 2004, it took the world about a year to add one gigawatt of solar power capacity. By 2023, the same amount was added, on average, every single day.
For reference, a gigawatt of solar is enough to power approximately 200,000 homes in the US.
Much of this growth has been driven by China, which by 2023 accounted for about 43% of the cumulative installed capacity worldwide.
A big reason for this acceleration has been a large decrease in the price of solar panels. Since 2001, the price has dropped by about 95%, from $6.21 to $0.31 per watt.
Learn more about why renewables like solar became so cheap so fast →
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 →
March 20
In every country in the world, women live longer than men — but the size of this gap in life expectancy varies widely.
The difference is striking in some countries, like Russia and Ukraine, where women’s life expectancy is over 10 years longer. Their gaps have been wide due to higher death rates in young and middle-aged men — often due to alcohol use, smoking, and other risks. The war in Ukraine has widened this gap further, as men face high mortality from conflict.
The gap is much smaller in other countries, including in West Africa and South Asia. There are likely multiple reasons for this, including higher rates of maternal mortality and HIV among women. Just a few decades ago, Bangladesh and India had shorter female than male life expectancies due to higher rates of female infanticide and neglect in childhood, and the gap in lifespans in these countries is still relatively small.
Many factors affect life expectancy, and the sex gap in lifespans has varied widely across countries and over time.
You can read more in my article about why women live longer than men →
March 19
The world's population has more than doubled over the last 60 years, but global food production has managed to keep up.
The chart shows the change in four indicators since 1961: cereal production, cereal yields, land use for cereals, and population. Each metric is expressed in its relative change since 1961 (which is given a value of zero).
Cereal production has increased by 3.5-fold, more than the 2.6-fold growth in population. That means production has grown faster than the population, and the world produces more cereal per person than 60 years ago.
We can also see what has driven this increase. You can grow more food by either increasing crop yields or using more land. While land use has increased, most of this growth has come from higher crop yields. This has spared some natural habitats from being converted into farmland.
Read more in my article on the Green Revolution and food production →
March 18
Putting a number on “happiness” is hard. But one way to better understand how satisfied people are with their lives is to ask them.
Self-reported life satisfaction is one key metric that researchers rely on. Respondents are asked to rate their lives on a 10-step ladder, where 0 represents the worst possible life, and 10 is the best.
The chart shows self-reported life satisfaction measured against gross domestic product (GDP) per capita. The two are positively correlated: people in richer countries tend to be more satisfied with their lives.
Of course, income is not the only thing that matters. You can also see the large spread of values for countries with similar levels of GDP per capita. For example, South American countries tend to have higher happiness levels than those in other regions.
Explore more data on life satisfaction across countries, within countries, and over people’s lifespan →
March 17
When we emit carbon dioxide (CO2) into the atmosphere, most of it stays there for centuries or millennia. This means that CO2 emitted even a century ago has contributed to the rising temperatures we see today.
In other words, how much the climate warms depends on how much cumulative CO2 is emitted over time.
The chart shows the ten countries with the largest share of the world’s historical emissions, based on cumulative emissions from fossil fuels and industry since 1750.
The United States has contributed the most, accounting for almost one quarter. This is followed by China and Russia.
There are many other ways to understand contributions to climate change – explore data on annual, per capita, and trade-adjusted emissions →
March 14
Global average yields of cereal crops have tripled over the past 60 years. This has been crucial to feeding a growing population while sparing natural habitat from expanding agricultural land.
However, some cereal crops have seen much larger gains in efficiency. Maize (corn) and rice achieve the highest yields and have seen huge gains in recent decades. Wheat and barley have also performed well.
As the chart shows, crops like sorghum and millet have lagged behind. A hectare of land could yield 5 to 6 tonnes of corn or rice but only 1 to 1.5 tonnes of millet and sorghum.
It’s not just that yields for these crops are much lower today; growth over the past 60 years has been much more modest, increasing by less than 50%.
This is a huge challenge since these are key staple crops across much of Sub-Saharan Africa, where hunger rates are the highest and farmer incomes are the lowest.
Read more in my article on increasing yields in Sub-Saharan Africa →
March 13
Government spending on health has grown substantially across rich nations since 1990, with particularly steep increases in the United States. The chart shows healthcare spending as a share of gross domestic product (GDP) in four countries.
Japan and the UK saw their share more than double, while it more than tripled in the United States, from 4.5% to 16% of GDP. The rising costs partly reflect demographic change, as older populations typically need more medical care, as well as the COVID-19 pandemic.
Each country organizes healthcare differently. Germany requires everyone to buy insurance from regulated providers, while Japan gives everyone government insurance. The United Kingdom provides healthcare directly through its national health service, while the US combines private insurance with government coverage for the elderly and those on low incomes.
Explore government health spending for more countries →
