Population and Environmental Trends, 1800 to the Present

By Bridgette Byrd O’Connor
Our changing climate is one of the most talked-about current events—for good reason. It’s an issue that began with industrialization and might only be solved if we are willing to change how we live.

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A photograph of a hazy, dark orange sky over an industrial city. Tall smokestacks emit large billows of smoke.

Introduction

It can be hard to grasp the impacts of climate change. Understanding it involves data sets, complex vocabulary, and confusing political views. How can we make sense of the overwhelming amount of information that is out there? One way is to look at how environmental changes since 1800 have been intertwined with industrialization and enormous increases in the global population.

The Industrial Revolution in the nineteenth century changed how we work, where we live, and how many of us there are. Improvements in machinery and agriculture produced enough food for a population explosion. More people moved to cities for factory jobs. Human migration created new cultural and economic networks of exchange, which connected and further globalized the world.

By the mid-nineteenth century, industrialization spread throughout the world. It benefitted some areas more than others. European nations and the US gained the most. These wealthy, industrialized nations extracted resources from Africa, Asia, and Latin America to fuel their own growth. By the end of the nineteenth century, this uneven system of exchange affected everyone one way or another.

Population Explosion

We know industrial acceleration and globalization caused population growth. In 1803, the global population reached 1 billion for the first time. It grew to 2.5 billion in 1950, 5 billion in 1987, and 8 billion today. Much of that growth can be linked to the effects of industrialization, namely food production.

Detailed, illustrated map of Manhattan in 1874. Most buildings are short, with few high rises, and the island is surrounded by ships.

Manhattan, New York City, 1874. By George Schlegel, public domain.

A modern-day photograph of Manhattan shows a vast number of high rise buildings.

Manhattan, New York City, 2014. By Anthony Quintano, CC BY 2.0.

There were also periods when the population fell dramatically in a short period of time, caused by the two world wars and the influenza outbreak of 1918. Industrialization was a factor in these population drops, as new weapons made wars deadlier and improved transportation helped deadly germs spread faster. However, innovations in medicine, transportation, and communication—all products of industrialization—let the population recover faster than it ever had in the past.

Table 1: Total Population by Region (in millions, rounded)1

Region 1820 1900 1950 2000
North America              12              82 173 313
Central and South America 24 66 169 526
Africa 89 141 229 818
Europe 219 421 549 727
Asia 745 939 1400 3730
Oceania 1 5 13 32
World 1090 1654 2533 6145

Increased Urbanization

After 1800, the areas where population increased the most were cities. For example, in 1800, no region in the world had more than 13 percent of its population living in cities. By 2000, these numbers skyrocketed, as the table below shows. By 2008, the percentage of people living in urban areas is now more than those living in rural areas.

Table 2: City Life: Percentage of Urban Population by Region

Region 1800 1900 1950 2000
North America 6.6% 33% 56% 77.6%
Central and South America 8.6% 24.3% 39.6% 72%
Africa 3% 6% 16.5% 38.7%
Europe (not including Russia) 12.5% 30% 48% 67.5%
West and Central Asia 3.4% 13.6% 32.8% 61.6%
South and East Asia 4.8% 11.6% 19.8% 46.8%
Oceania 8% 35% 72% 82%
World 7% 16% 29% 47%

 

Urbanization had generally negative effects on health, as disease and pollution increased as more people lived clos- er together. Over time, innovations in medicine and sanitation took care of some of these problems.

Advances in medicine also increased life expectancy. In 1770, people lived to about 29 years while only 100 years later, in 1870, they lived to 30 years old. By the early twenty-first century, life expectancy was up to 71 years. These numbers vary around the world. Developing economies, such as those in Africa and Southeast Asia, have seen smaller increases in life expectancy.

Environmental Changes

The increases in population and life expectancy may make it seem as though everything got better over this time, but unfortunately, that’s not the case. The industrial world depends on fossil fuels, and burning them releases carbon dioxide (CO2) into the atmosphere.

For 400,000 years, the carbon dioxide level never exceeded 300 parts per million (ppm). Even for the first 200 years of industrialization, CO2 levels stayed under this level. But the levels soon reached this peak after World War II. Currently, it stands at 421 ppm. So why does this matter and how does this relate to population growth?

High levels of CO2 in the atmosphere cause global temperatures to rise. We are already 1.5 degrees Celsius above what’s normal. The rise in CO2 and global temperatures cause ice at the poles to melt, making sea levels rise. Human communities living near coastal areas are endangered by rising sea levels, and so are animal habitats. Nearly half of the human population currently lives within 100 miles of a major body of water, so these rising waters will be a major challenge of the future.

But it is not just species on land that are in danger. According to a 2019 report released by the US National Oceanic and Atmospheric Administration, there have been notable CO2 increases in the Earth’s oceans.

“The global ocean absorbed 34 billion metric tons of carbon from the burning of fossil fuels from 1994 to 2008—a fourfold increase of 2.6 billion metric tons per year when compared to the period starting...1800 to 1994” (NOAA).

These increases make the oceans more acidic, endangering marine life. For example, shellfish are finding it harder to make their shells because of the water’s increased acidity. Luckily, the oceans absorb some of the CO2 that would otherwise lead to ever-increasing temperatures. However, an important question is whether the oceans can continue to absorb this much CO2.

Carbon dioxide levels and other pollutants have been increasing since the early nineteenth century. Coal was burned to power factories, trains, and ships, while new engines were developed that relied on oil and gas. More resources, more production, and more fuel were needed as the global population doubled in the twentieth century.

By the mid-twentieth century, people were feeling the effects of fossil fuel use. Episodes of toxic air pollution in Donora, Pennsylvania, and London, England, caused more than 4,000 deaths in 1948 and 1952. In the 1960s, scientists and governments began to call for environmental legislation to lessen the dangerous effects of industrialization. Many of these actions helped reduce pollution. For example, between 1960 and 2010, Los Angeles greatly reduced the amount of smog in its air.

There is still much more work to do. Climate scientists warn that if we do not act quickly to reduce emissions, both the Earth and humanity may be doomed. 

So now what?

Collectively, humanity must cooperate. If we lower CO2 levels and curb plastic use, we can replace these fuels with renewable energy resources like solar, wind, and water power. But what can we do as individuals to help our community and our planet?2

A photograph of a group of young girls protesting at a climate strike, holding up handmade signs. One sign reads “SOS”, the ‘O’ replaced by a melting planet Earth.

In September of 2019, climate activists organized a worldwide “climate strike” to demand world leaders address climate change with more urgency. By Ckohtala, CC BY-SA 2.0.

Environmental activist Jane Goodall recommends thinking about the environmental impact one’s actions. “Everyday you live you make some impact. So start thinking about the consequences of the little choices you make,” she said. “What do you buy? Where did it come from? Did it harm the environment?” If the majority of Earth’s 8 billion population took the time to think about these choices on a daily basis, we could dramatically change the way we interact with the environment.


1 As of September 4, 2024, the world population according to the US Department of Commerce, Census Bureau was 8 billion. A visit to https://www.census.gov/popclock/ will tell you the current estimate.
2 To explore ways that you can help combat climate change, check out the articles, videos, and activities in Climate Project.

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Bridgette Byrd O’Connor

Bridgette Byrd O’Connor holds a DPhil in history from the University of Oxford and taught Big History, world history, and AP US government and politics for 10 years at the high-school level. In addition, she has been a freelance writer and editor for the Big History Project and the Crash Course World History and US History curricula. She’s currently a content manager for OER Project.

Image Credits

Creative Commons This work is licensed under CC BY 4.0 except for the following:

Cover: OBERHAUSEN, GERMANY - JANUARY 06: Steam and exhaust rise from different companies on a cold winter day on January 6, 2017 in Oberhausen, Germany. According to a report released by the European Copernicus Climate Change Service, 2016 is likely to have been the hottest year since global temperatures were recorded in the 19th century. According to the report the average global surface temperature was 14.8 degrees Celsius, which is 1.3 degrees higher than estimates for before the Industrial Revolution. Greenhouse gases are among the chief causes of global warming and climates change. © Photo by Lukas Schulze/Getty Images.

Manhattan, New York City, 1874. By George Schlegel, public domain. https://commons.wikimedia.org/wiki/File:George_Schlegel_-_George_Degen_-_New_York_1873.jpg

Manhattan, New York City, 2014. By Anthony Quintano, CC BY 2.0. https://commons.wikimedia.org/wiki/File:Above_Gotham.jpg

Global temperature increases historical from 1880 and projected to 2020. NASA, public domain. https://commons.wikimedia.org/wiki/File:Global_Temperature_Trends.png

In September of 2019, climate activists organized a worldwide “climate strike” to demand world leaders address climate change with more urgency. By Ckohtala, CC BY-SA 2.0.


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