Introduction

It can be hard to understand the impacts of climate change. How can we make sense of all the information that is out there? One way is to look at the world since 1800. The environment has changed greatly since then. This is related to industrialization and a rise in the global population.

The Industrial Revolution changed the world in the 1800s. It changed how we work, where we live, and how many people are on the earth. 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. These changes helped European nations and the United States more than other countries. These nations took resources from Africa, Asia, and Latin America. These resources then helped the wealthy and industrialized nations. By the end of the 1800s, everyone was affected by industrialization.

Population Explosion

We know that increased industrialization caused population growth. In 1803, the global population reached 1 billion for the first time. In 1950, the population grew to 2.5 billion. It doubled to 5 billion by 1987. Today, there are about 8 billion people.

There were also periods when the population fell. Both of the world wars caused many deaths around the world. There was also the influenza outbreak in 1918 when many people became sick and died. Industrialization played a role in these disasters. Mass production of weapons made wars deadlier. Better transportation allowed germs to spread more easily. However, industrialization also led to advances in medicine. This helped the population go back up again quickly.

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

Increased Urbanization

After 1800, cities saw the biggest increases in population. The table below shows this change. There are now more people living in cities than in rural areas. In 1800, most nations had less than 13 percent of their populations living in cities. By 2008, the percentage of people living in cities was 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, or how long people are expected to live. In 1770, people lived to about 29 years old. In 1870, this only increased to 30 years. By the early twenty-first century, life expectancy was up to 71 years. These numbers are different around the world. Parts of Africa and Southeast Asia have seen smaller increases in life expectancy.

Environmental Changes

It may seem like everything has improved over this period of time. Unfortunately, that is not completely true. Industrialization depends on fossil fuels such as coal, petroleum, and natural gas. These have had negative effects on the environment. They release carbon dioxide (CO₂) into the air.

Burning fossil fuels has raised the level of carbon dioxide in the atmosphere. High levels of carbon dioxide 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 415 ppm. We are already 1 degree Celsius above what is normal. The rise in global temperatures causes ice at the poles to melt. Melting ice causes sea levels to rise. Higher sea levels affect people and animals who live on coasts. Nearly half of the human population 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.

Marine life is also put in danger. The world’s oceans have seen increases in CO₂ levels. These increases make the oceans more acidic. Shellfish have difficulty making their shells because of the ocean’s high acidity.

Carbon dioxide levels have been increasing since the early 1800s. Factories, trains, and ships were powered by coal. Then there were engines using oil and gas. More people used electricity, which usually came from burning coal. The growing population needed more resources, more production, and more fuel.

By the mid-1900s, the effects of fossil fuel use became very clear. In 1948 and 1952, air pollution in Pennsylvania and London was killing people. In the 1960s, scientists began to call for action. They introduced legislation, or laws, to help reduce pollution. For example, the city of Los Angeles has a problem with smoky fog, or smog. It reduced the levels of smog between 1960 and 2010. However, we still have much more to do. Carbon dioxide levels stopped rising in the early twenty-first century. They are now rising again.

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. It is possible to switch to 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

Jane Goodall is an environmental activist. She says we must think about the environmental effects 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.