Today, the global population is estimated to sit at 7.91 billion people.

By the end of 2022 or within the first months of 2023, that number is expected to officially cross the 8 billion mark. Incredibly, each new billion people has come faster than the previous—it was roughly only a decade ago that we crossed the 7 billion threshold.

How did we get here, and what has global population growth looked like historically?

In this series of six charts from Our World in Data, we’ll break down how the global population got to its current point, as well as some big picture trends behind the data.

#1: Mapping the Population Over 5,000 Years

New York, São Paulo, and Jakarta were not always bustling metropolises. In fact, for long parts of the history of civilization, it was unusual to find humans congregating in many of the present-day city locations we now think of as population centers.

The human population has always moved around, seeking out new opportunity and freedoms.

As of 3,000 BC, humans could be mainly found in Central America, the Mediterranean, the Fertile Crescent, and parts of India, Japan, and China. It’s no coincidence that that agriculture was independently discovered in many of these same places during the Neolithic Revolution.

#2: The Hockey Stick Curve

For even more context, let’s zoom way out by using a timeline that goes back to when woolly mammoths still roamed the Earth:

From this 10,000-foot view, it’s clear that human population growth started going exponential around the time of the Second Agricultural Revolution, which started in the 17th century in Britain. This is when new technologies and farming conventions took root, making it possible to grow the food supply at an unprecedented pace.

Soon these discoveries spread around the world, enabling population booms everywhere.

#3: The Time to Add 1 Billion

The data and projections in this chart are a few years old, but the concept remains the same:

It took all of human history until 1803 to reach the first billion in population. The next billion took 124 years, and the next 33 years. More recent billions have come every dozen or so.

So why then, are future billion people additions projected to take longer and longer to achieve?

#4: The Growth Rate is Shrinking

Because of demographics and falling fertility rates, the growth rate of the global population has actually been on a downward trend for some time.

As this growth rate gets closer to zero, the population curve has become less exponential like we saw in the first graphs. Population growth is leveling out, and it may even go negative at some point in the future.

#5: The Regional Breakdown

Although the rate of population growth is expected to slow down, there are still parts of the world that are adding new people fast, as you can see on this interactive regional breakdown:

Since 1973, Asia has doubled its population from 2.3 billion to 4.6 billion people.

Comparatively, over the same time frame, Europe has gone from 670 million to 748 million, equal to just an 11% increase.

#6: The Present and Future of Population Growth

Population projections by groups like the United Nations see the global population peaking at around 10.9 billion people in 2100.

That said, there isn’t a consensus around this peak.

Organizations like the Institute for Health Metrics and Evaluation (IHME) have a different perspective, and they have recently modeled that the global population will top out at 9.7 billion people by the year 2064.

As we climb to surpass the 8 billion mark in the coming months, it will be interesting to see what path humanity ends up following.

Mapped: The Geography of Global Literacy

Literacy is a fundamental building block that can lead to a strong education, the ability to solve complex problems, and gaining the skills and knowledge to participate meaningfully in society. As a result, it’s also an important facilitator of economic development.

However, it’s estimated that nearly 800 million adults around the world still lack basic literacy skills—and this can create ongoing drag on the economy.

In the U.S., as one example, the people with the lowest literacy scores are 16.5x more likely to receive financial aid from the government. At the same time, they are also more likely to be in the lowest earning wage group, earning less than $300 per week.

Today’s post uses charts from Our World in Data, and it shows what literacy looks like on a global scale, and how is it shifting from generation to generation.

Global Literacy: The Big Picture

Over the past two centuries, global literacy has seen steady growth.

In the year 1800, it’s estimated that a mere 12.1% of the world was able to read and write. The most recent data shows the numbers have actually flipped—and now just 13.8% of the global population is illiterate.

It’s clear that from a high level, progress towards global literacy is being made.

But at the same time, a look at the graph shows that in more recent years, the rate of change has been slowing as we reach the “last mile” of literacy.

The Generational Perspective

Learning to read and write is easiest and most fruitful at a young age, and it’s a skill that is very unlikely to be lost later in life. For that reason, it’s worth looking at the difference between older and younger generations in terms of who is learning these skills.

For this, we zoom into the Middle East and Northern Africa region, which is where the majority of recent gains in literacy have been made:

Here, the difference in literacy between the 15-24 year age group and those over 65 years is substantial, with countries seeing large, double-digit increases in the ability to read and write:

• 🇩🇿 Algeria
  The literacy rate is at 92% for the 15-24 age group, compared to 16% of the oldest generation
• 🇮🇷 Iran
  99% of the 15-24 age group is literate, while 29% of the oldest generation can say the same
• 🇴🇲 Oman
  98% of those aged 15-24 are literate, compared to just 23% in the 65+ age group
• 🇸🇦 Saudi Arabia
  98% of those aged 15-24 can read and write, versus 26% of those in the oldest bracket
• 🇪🇷 Eritrea
  The literacy rate is at 90% for the 15-24 age group, and 18% for those in the 65+ age group

It’s not that surprising then, that the above countries all now sit in the 75-95% percent range for overall literacy—a number that will likely improve further as education systems continue to help younger generations become literate early in life.

The Literacy Opportunity

While some countries have seen obvious generational improvements in literacy, there are places in the world where changes to educational systems have not fully yet manifested yet, or perhaps the data is not yet available for.

According to the interactive map above, here are some places on each continent where progress must still be made:

• North America
  Literacy rates: 🇭🇹 Haiti (61%), 🇬🇹 Guatemala (79%), 🇳🇮 Nicaragua (82%)
• South America
  Literacy rates: 🇬🇾 Guyana (88%)
• Europe
  Literacy rates: 🇽🇰 Kosovo (92%)
• Asia
  Literacy rates: 🇦🇫 Afghanistan (38%), 🇵🇰 Pakistan (56%), 🇧🇩 Bangladesh (61%), 🇾🇪 Yemen (70%)
• Africa
  Literacy rates: 🇳🇪 Niger (19%), 🇬🇳 Guinea (30%), 🇸🇸 South Sudan (32%), 🇲🇱 Mali (33%), 🇨🇫 Central African Republic (37%), 🇸🇴 Somalia (38%), 🇧🇯 Benin (38%)
• Oceania
  Literacy rates: 🇵🇬 Papua New Guinea (62%)

With many NGOs and educators focused on this problem, there is hope that the “last mile” of global literacy can be solved, leading to more economic opportunity in these places—and also the world itself as a whole.