Introduction

It can be hard to grasp the impacts of climate change. It may involve understanding data sets, complex vocabulary, and confusing political views. How can we make sense of all the information? One way is to look at environmental changes since 1800. They are closely related to industrialization and enormous increases in the global population.

The Industrial Revolution in the 1800s changed how we work, where we live, and how many of us there are. Better technology led to more food production. The world population grew because there was more food. More people moved to cities for industrial jobs. New networks of exchange were created as the world became more globalized.

By the mid-1800s, industrialization spread throughout the world. European nations and the US benefitted the most. These nations took resources from Africa, Asia, and Latin America. These resources then fueled the growth of wealthy, industrialized nations. By the end of the 1800s, everyone was affected by industrialization in some way.

Population Explosion

We know industrial acceleration and globalization caused population growth. In 1803, the global population reached 1 billion for the first time. The population grew to 2.5 billion in 1950. It doubled to 5 billion by 1987 and today is 8 billion. That growth was greatly affected by the results of industrialization, such as food production.

There were also periods when the population fell. Two large drops were caused by the two world wars and the influenza outbreak of 1918. Industrialization played a role in these disasters. Mass production of weapons made wars deadlier. Improvements in transportation made germs spread more easily. However, advances in medicine, transportation, and communication helped the population recover more quickly.

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

Increased Urbanization

After 1800, the areas where the population increased the most were cities. The table below shows this change. In 1800, no part of the world had more than 13 percent of its population living in cities. By 2008, the percentage of people living in urban areas is more than in rural areas.

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

Urbanization was generally bad for the health of the population. Disease and pollution went up as people lived closer together. Advances in medication have taken care of some of these problems.

Advances in medicine also increased life expectancy. In 1770, people lived to about 29 years old. By 1870, this only increased to 30 years. 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 rising population and life expectancy may make it seem as though everything got better over this time. Unfortunately, that is not entirely true. Industrialization has had negative effects on the environment. This is due to the dependence on fossil fuels such as coal, petroleum, and natural gas.

Burning fossil fuels has raised the level of carbon dioxide (CO₂) in the atmosphere. High levels of CO₂ cause global temperatures to rise. For the first 200 years of industrialization, CO₂ levels did not pass 300 parts per million (ppm). Now, we are at 421 ppm. We are already 1.5 degrees Celsius above what is normal. The rise in global temperatures causes ice at the poles to melt, making sea levels rise. This endangers humans and animals who live in coastal areas. Nearly half of the human population currently lives within 100 miles of a major body of water

It is not just species on land that are in danger. The world’s oceans also have seen increases in CO₂ levels.

“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).

This increase endangers marine life. Shellfish are finding it harder to make their shells because of the water’s increased acidity. The ocean absorbs CO₂, which does prevent it from entering the atmosphere. This keeps temperatures lower. However, it is not known whether the oceans can continue to absorb this much CO₂.

Carbon dioxide levels have been increasing since the early 1800s. The increase began with factories, trains, and ships powered by coal. It continued with engines using oil and gas. More people required electricity, which was usually generated from the burning of coal. More resources, more production, and more fuel were needed as the global population increased.

By the mid-1900s, the effects of fossil fuel use became very clear. In parts of Pennsylvania and London, toxic air pollution was causing deaths in 1948 and 1952. In the 1960s, scientists and governments began to call for environmental legislation. They hoped this would help reduce pollution. For example, between 1960 and 2010, Los Angeles greatly reduced the amount of smog in its air.

Climate scientists warn we must act quickly to reduce emissions. If not, both the Earth and humanity may be doomed.

So now what?

Humans must cooperate to lower CO₂ levels and reduce plastic use. Some fossil fuel use can be replaced by energy resources like solar, wind, and water power. Individuals can help the planet by making environmentally friendly choices every day. Then we could change the way we interact with the environment.²

Environmental activist Jane Goodall says we must think about the environmental impact of our actions, “Everyday 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.