People have become very good at farming. Over the years, we have learned to grow more and more food. This has allowed the world's population to grow too. In the last 100 years, it has grown four times its size.

In the coming years, feeding more and more people might be hard. Earth is heating up. This type of climate change is called global warming. It causes changes in weather patterns, such as rainfall. These changes may make farming harder.

Farmers are also partly responsible. They often grow food in ways that are not sustainable. Sustainability means balancing human and ecosystem needs. It also means thinking about these needs for the future.

Growing food can harm an ecosystem. Below are three ways that farming affects the environment.

Irrigation

Freshwater is stored in lakes, rivers, and underground. People use it for washing and drinking. They also use it for growing food. Farming takes up 70 percent of the freshwater that we use.

A lot of freshwater is used for irrigation. Irrigation is when farmers water crops. They use pipes, canals, or sprinklers to water them. They use irrigation to grow large amounts of food.

Irrigation affects ecosystems. It takes water out of rivers, lakes, or underground. In these areas, the soil can become too salty. This harms plants. Irrigation can also flood land. This harms plants too.

Farm Animals

A lot of farm land is used for cows. This is very true in the western United States. Animals need land for grazing. This is when animals eat grass in pastures.

Farm animals often release greenhouse gases. These gases trap heat in Earth's atmosphere. They make the planet warmer. This causes climate change. One major greenhouse gas is methane. Cows and their waste release a lot of methane.

Farm animals can also cause overgrazing. This is when too many animals eat on the same piece of land for too long. It harms plants. Some types of plants may be unable to grow back.

Fertilizers

Many farmers depend on fertilizers. They spread fertilizers over fields or into dirt. This helps plants grow.

Fertilizers are made of nitrogen and phosphorus. These are nutrients that plants need. However, they can pollute ecosystems. About half the nitrogen in fertilizers ends up in soil, air, and water.

Large amounts of nitrogen and phosphorus harm ecosystems. They become loaded with too many nutrients. This causes algae to grow quickly in lakes or oceans. The algae uses up oxygen in the water. But other animals and plants in the water need oxygen, too. Many of these organisms die.

Feeding people into the future will be hard. Moving forward, we might have to find different ways of farming.