Food production can cause environmental problems or issues when the absorptive or regenerative capacity of the system is exceeded.
In this video, I give an overview of these issues.
I will talk about three types of issues: pollution problems, resource depletion and issues related to land use.
Let me start with pollution problems.
These are the result of emissions of pollutants to air, water and soil.
Pollution occurs when levels of chemicals or other compounds in the environment are too high.
Pollution is almost always the result of human activities.
When we grow our food, there are always losses of potential pollutants to the environment.
The problems they cause may be local, regional or even global.
I will give examples of each.
Local issues occur when pollutants cause problems close to where they were released.
For example, local water pollutants include nutrients, pesticides and heavy metals.
In areas with intensive food production, the ground water may become polluted.
This is caused by leaching of pollutants from the soil to the ground water.
When the ground water is used as a source for drinking water, this may become a serious problem.
But pollutants don’t stay in one place - they travel.
Thereby creating regional and even global issues.
There are basically two ways of transportation: by air, and by water.
As a result, pollution problems may occur far from the source of pollution.
When water pollutants reach the groundwater or surface waters, they can travel over large distances.
For instance rivers can transport nutrients to the seas, resulting in algal blooms in coastal seas.
These algal blooms cause problems for ecosystems, because the algae can take away all oxygen.
Pollution can also occur in the air.
Air pollutants are mostly gases that are emitted into the atmosphere.
Local air pollutants from food production include ammonia, nitrogen oxides, particulate matter and pesticides.
For instance, close to livestock production sites there may be high concentrations of ammonia in the atmosphere.
This may not only cause a bad smell, it can also be harmful for vegetation and even be toxic.
When the winds take air pollutants, such as ammonia and nitrogen oxides, they can travel over longer or shorter distances.
They can cause two types of regional problems:
1) Acidification is the problem of too much acid in the environment.
2) Eutrophication is the problem of too many nutrients in the environment.
Emissions of greenhouse gases such as carbon dioxide, methane and nitrous oxides can also have an impact at the global scale.
They are mixed in the atmosphere and affect the global climate, regardless where they were emitted.
Now let’s have a look at the second type of environmental issues: resource depletion.
There are two types of resources: non-renewable and renewable resources.
Examples of non-renewable resources are fossil fuels and phosphate.
These are finite resources. We take them from the natural stock, until there is none left.
This is one of the reasons why we can be certain that at some point our societies will switch from fossil fuels to renewable energy sources.
For phosphate it is not easy to find an alternative.
Therefore, it is important to increase the nutrient use efficiency of food production,
and to develop ways to recycle phosphate.
Examples of renewable resources are, for instance, biogas, fish stocks and soils.
In a sustainable world, we do not take more from the renewable stock than the systems can regenerate.
In the current world, however, there is often over-exploitation of renewable resources.
For example, we do not properly use soils, resulting in soil erosion.
Finally, let’s have a look at the third type of environmental issues: land use change.
To grow food, we need land.
However, the world population is growing.
And we eat more meat than a few decades ago.
As a result, we need more and more land for food production.
This raises the question: is there enough room for nature left?
Taking land from nature will affect biodiversity.
There is a loss of biodiversity because of habitat loss, and because of habitat getting smaller.
Currently, the area of tropical rain forest is declining fast.
If we do not try to stop this trend, there may be very little rainforest left in the future.
You have now seen how food production contributes to different types of environmental issues:
pollution problems, resource depletion, and land use change.
From this list of examples it is clear that sustainable food production is complex.
There are many aspects related to it.
It will be a challenge to grow enough food for a growing world population in a sustainable way.