People have continuously managed to grow more food. Over the years, farmers and scientists have discovered ways to grow crops stronger, bigger and faster. This has drastically increased the amount of food we produce.

These huge increases in food have allowed the world's population to grow. In fact, it has quadrupled over the last century. As the population grows, so does the amount of space that we need to feed people. In 2022, farmers used more than 7.3 million square kilometers (2.8 million square miles) to grow corn, wheat, rice and other grains. That's nearly half of all cropland on the planet.

In the coming decades, feeding a growing population will become more difficult. Humans have been burning fossil fuels, like coal and oil, for electricity and fuel. This produces greenhouse gases. Greenhouse gases are heating Earth. This has led to an increase in droughts and heavy rains. These changes in global climate—known as climate change—may make growing food more difficult.

Modern agriculture is also partly responsible for its own problems. Although they don’t mean to, farmers often use methods that are not sustainable. Farming sustainably means not using too many of Earth's natural resources or harming ecosystems. It ensures that future generations can meet their needs, too. Sometimes, farmers are only able to grow a lot of food in ways that harm ecosystems.

There are many ways in which agriculture harms ecosystems. Three main ways are irrigation, animal grazing and chemical fertilizers.

Irrigation

Worldwide, 70% of the freshwater that people use goes to agriculture. Much of this water is used for irrigation, or the process of watering crops through pipes, canals and sprinklers. Irrigation is necessary for growing a lot of food. It helps grow food in places with little water, like deserts. Experts think that agricultural water use will need to increase by 15% or more by 2050. It will have to increase to feed the growing population.

Farmers don’t mean to waste water, but sometimes they use more water than the crops need. This can happen when the irrigation system is too old or not installed properly. Not growing cover crops can also lead to too much water use. Cover crops protect soil health. Without them, the soil might not absorb water well.

Irrigation has consequences for the environment. One major consequence is draining water out of rivers and underground water systems. Irrigation can also cause floods, which can make the soil poisonous to plant roots. In areas where water has been drained, the soil can become too salty. This also harms plant growth.

Irrigation also increases water evaporation, or the process that turns liquid into gas. This affects air temperature and pressure. It also affects moisture in the air. Studies have shown that irrigation can change rainfall thousands of miles away from the irrigated areas.

Fixing issues with irrigation is expensive and not all farmers can afford it. The crops people want to buy often need more irrigation. Farmers choose to plant these crops to make more money. It can be hard to make good watering decisions. Better education could help farmers improve how they use water.

Animal Grazing

A huge amount of agricultural land is used for cows and other animals. Farmers can make money from these animals because they are popular sources of meat and dairy goods. In the western United States, hundreds of millions of acres are set aside for animal grazing. When animals graze, they eat grass in pastures.

Animal farming is responsible for a large part of greenhouse gas emissions. Greenhouse gases trap heat in Earth's atmosphere. This causes the planet to warm. Methane and carbon dioxide are two major greenhouse gases. Cows and their manure are responsible for releasing huge amounts of methane. Land use and destruction also lead to the release of carbon dioxide into the atmosphere.

In addition, overgrazing is a major problem for environmental sustainability. In some places, land is grazed so much that grasses cannot grow back. Their root systems can get very damaged. Certain types of native plants might even die off.

Cows often concentrate near streams and other waterways. Together, overgrazing and cow waste can pollute water sources. Cows can also damage the soil. Then, the soil gets swept away by wind and water.

Making space for cow grazing is a serious threat to the Amazon rainforest. Cutting down trees to make room for cows makes up 80% of forest removal—known as deforestation—in the Amazon. The Amazon is home to 10% of the species we know about. This diversity of living things is known as biodiversity. It’s a sign of a healthy ecosystem.

The Amazon rainforest also helps with climate change. Its many trees remove carbon dioxide from the atmosphere. This helps keep Earth’s temperature from getting too hot. Removing this forest impacts the people who live there too. Some of these farms in the Amazon have harsh working conditions. Farm owners have also removed the people who originally lived in the Amazon, called Indigenous people, from their land.

One solution to stop cows from grazing too much is rotational grazing. To do this, farmers divide their pastures and only allow the cows to graze in one area at a time. Farmers then move the cows to a new section before they can eat all the grass. But this method costs money to set up. It is also more complicated than regular grazing. This is because it requires the farmer to make changes based on factors like the size of the herd and the quality of the local soil.

Chemical Fertilizers

Modern agriculture depends on chemical, or human-made, fertilizers. These are compounds that farmers spread over crop fields or into soil. They contain nutrients that plants need to grow, such as nitrogen and phosphorus. They help grow many of the foods people like to eat, like corn, wheat and rice crops.

Human-made fertilizers have helped increase how much food we can produce by a large amount. But they have also increased nitrogen and phosphorus levels in the environment. About half the nitrogen in chemical fertilizers escapes from crop fields. It finds its way into the soil, air and water.

Large amounts of nitrogen and phosphorus harm ecosystems and humans. Ecosystems can have too many nutrients. In bodies of water, algae, or small aquatic organisms, use these nutrients to grow. This process is called eutrophication. When the algae decay, they use up the oxygen in the water. This leaves very little oxygen for other plants and animals in the water. These areas of little to no oxygen are called "dead zones" because the organisms living there die without oxygen. Too much chemical fertilizer is also not good for female farmers. Overuse can contribute to health issues for pregnant women and their babies.

Agriculture Working in Harmony with the Environment

Farming does not need to harm the environment. Some farming methods can even decrease environmental impacts. For example, planting cover crops and not tilling or disturbing the soil helps the environment. These methods are part of a system called regenerative agriculture. This system supports healthy ecosystems, communities and economies. Regenerative agriculture also helps farms deal with climate change.

Regenerative agriculture is not a new system. Indigenous people around the world have used this kind of farming successfully for centuries. However, the Europeans who invaded and colonized other lands often forced Indigenous people to give up their lands and farming practices. In recent years, people have rediscovered these farming practices.

One of these practices is polyculture. This is when farmers grow many crops at once. This is how an ecosystem supports many species at once. It’s different from farming one crop at a time, which is known as monoculture. Most large farms use the monoculture method.

Because polyculture supports many species, it encourages biodiversity. The crops that are grown together don’t compete for nutrients in the soil, so they grow well together. These systems also provide a variety of foods. That makes polyculture more reliable. If one type of crop doesn’t grow well, there are still other crops available.

Farming has contributed to the loss of pollinators like bees, bats and butterflies by removing their habitats. But over 75% of crops need pollinators to reproduce. In some regions, farmers are encouraged to grow plants that support pollinators. In Nigeria, for example, farmers have been provided these plants along with education and training in beekeeping.

Farming has also created inequalities that must be addressed. European colonizers and the U.S. government often removed land from certain communities to give to wealthy landowners. For example, wealthy White landowners created racist policies in the 20th century that forcibly removed millions of acres of land from Black farmers in the United States. As a result, White farmers in the United States still own most of the country’s farmland.

Women in agriculture are also treated unfairly. Historically, female farmers have not been able to access the same resources, like information or tools, as male farmers. But globally, this is improving. Organizations have created programs to help improve conditions for female farmers. For example, the United Nations (UN) Food and Agriculture Organization (FAO) is helping female farmers in Chad with irrigation projects. This has created more fertile land and improved crop growth.

As leaders in government come up with solutions for environmental issues in agriculture, they must also think about how these solutions may affect traditional agricultural communities. National Geographic Explorer Daun Lee wanted to address this challenge by interviewing tangerine farmers in Jeju Island, South Korea, who were considering converting their farmland into solar farms. For over a thousand years, tangerine farmers in this area have passed down their farming traditions. The income from converting their lands into solar farms could help some farmers retire. However, it might also disrupt long-held cultural traditions.

Through her work, Lee documented the concerns farmers had that the shifting land use could impact their heritage. “Cultural values and heritage tied to land use are important, and the loss of these values is irreversible,” she said.

Individuals can help make farming better for the environment and society by choosing to buy food from farms that use regenerative agriculture. They can also reduce their food waste and choose plant-based foods that emit less carbon.

There are also global efforts to improve how farming impacts the environment. UN organizations like the FAO and the Intergovernmental Panel on Climate Change (IPCC) work with governments, farmers and others. They study the impacts of farming on the environment and offer solutions to improve farming practices.

As the population continues to grow, agricultural productivity and environmental health will clash. We will have to find ways to feed people without harming the ecosystems that we need for growing food.