The Environmental Impact of Vegetable Oils

This is Part 4 in a series of posts investigating how vegetable oil impacts our health and our planet. If you’re new to the series, feel free to visit Part 1, 2, or 3.

We’ve established that industrial vegetable oils are bad for our health. To add insult to injury, they may be even worse for our planet. Canola, sunflower, soybean, and palm oil are some of the most environmentally destructive crops in the world:

  • More land is devoted to growing vegetable oil crops than all fruits, vegetables, legumes, nuts, roots and tubers combined.
  • 2 of the top 3 drivers of global deforestation are vegetable oil crops.
  • Vegetable oils emit more greenhouse gases per kilogram than any other major crop.
  • Vegetable oils require 20–30% of global crop lands, but deliver less than 0.01% of the world’s nutrients.

Land Use

We dedicate a lot of land to crops. About 12% of all habitable land on Earth, over 1.5 billion hectares, is dedicated to food crops for human consumption, up from 200–300 million hectares a few hundred years ago [1]:

While cereal grains are the crops that contribute most to land use, vegetable oil crops are second, and the land requirements for vegetable oils are growing significantly faster than cereals, or any other crop for that matter.

More land is devoted to vegetable oil crops than all fruits, vegetables, legumes (pulses), nuts, roots and tubers combined [2]:

Land area for vegetable oil crops has nearly tripled since 1961, and more than doubled since the 1970s. During that same time, land area for other crops like cereals has stayed relatively flat and has actually decreased since the 1970s.

Currently the world devotes 20–30% of all agricultural land, between 300–425 million hectares (1 billion acres), to vegetable oil crops. That’s an area similar to the size of India [3, 4]:

Vegetable oils don’t just have massive land use requirements because of their prevalence, they are also some of the worst types of crops when it comes to land use efficiency (how much land is required to produce one kilogram of food product).

Of all major food crops in the world (at least 10 million tonnes of global production), vegetable oils make up three of the top five most inefficient crops, requiring as much as 3–50 times more land per kilogram than most other crops [5, 6]:

An area of land used to grow one kilogram of “vegetable” oil from soybean, rapeseed (canola), or sunflower could instead produce 30–50 kilograms of actual vegetables, like spinach, sweet potatoes, and carrots.

Deforestation

The result of all that land devoted to vegetable oils is deforestation, a term that broadly describes the burning or clearing of natural ecosystems in order to make room for human activities.

Image source: Wired

Deforestation drives biodiversity loss and is the second largest contributor to global warming, after fossil fuel combustion [7]. Every minute, the equivalent of 40 football fields of rainforest is destroyed by deforestation, primarily for agriculture [8].

Two of the top three drivers of global deforestation are vegetable oil crops, soybean and palm oil, accounting for nearly one-fifth of tropical deforestation worldwide [9].

As forests go up in flames to make room for vegetable oil crops, one of the many negative consequences is an increase in harmful emissions–not only greenhouse gases but also more acutely dangerous air pollutants from smoke.

Emissions

Researchers at Harvard and Columbia Universities found that the smoke from one mass Indonesian blaze in 2015 to make room for palm oil production may have caused 100,000 premature deaths due to harmful air pollutants [10].

A few years later, it is estimated that the loss of primary tropical forest in 2019 resulted in the release of more than 2 billion tons of CO₂ or more than the emissions from all on-road vehicles in the United States in a typical year [11].

Partly due to their land requirements and role in deforestation, CO₂ emissions from vegetable oil crops are as much as 5–25 times higher than most other agricultural crops.

There are only five major food crops that emit more than 3 kg CO₂-equivalents per kg of food product, and four of them are vegetable oils [12]:

Chart adapted from Our World in Data. Note: Vegetable oil production also creates “meals” that are primarily fed to animals. For sunflower, palm, and rapeseed, 10–30% of the environmental impact is apportioned to animal products, increasing to ~60% for soy.

Combining the above emissions chart with the previous land use chart allows us to more easily visualize the environmental impact per kilogram of different foods, with the most environmentally friendly crops in the bottom-left (green) and the most environmentally harmful crops in the top-right (red):

High emission crops are defined here as greater than 3 kg CO₂-equivalent per kg food product and high land use crops as greater than 3 square meters of land use per kg of food product.

Although cocoa butter (the primary ingredient in dark chocolate) and olive oil are excluded here due to their relatively small volume as food crops, they would also be in the top-right (red) quadrant if included.

If we can avoid one category of crop-based food for the sake of the environment, vegetable oils appear to be it.

Biodiversity

According to the International Union for Conservation of Nature (IUCN), the foremost authority on species conservation, palm oil expansion alone could affect over half of the world’s threatened mammals and two-thirds of threatened birds globally. However, because other vegetable oil crops have lower yields than palm oil, “replacing it is not a solution,” says the IUCN [13].

While palm oil gets most of the global attention for its negative impact on rainforests, it is actually the most productive oil crop, producing more oil per land area than all other oil crops combined [14]. To illustrate, three times as much palm oil is produced globally compared to rapeseed (canola) oil, while requiring only half the amount of land:

The problem with palm oil is that it only grows near the equator and competes for land with biodiverse and carbon-rich tropical forests, where 2% of the Earth’s surface is home to 50% of our plant and animal species, threatening endangered species and emitting massive amounts of greenhouse gases [15].

While palm oil is devastating for the environment, it may be the lesser evil among other vegetable oil crops. If, for example, less productive soy was used to meet global vegetable oil demands, an additional 204 million hectares of tropical and subtropical land would be needed, or a 48% increase compared to now [16].

The chair of IUCN’s  palm oil task force describes the dilemma: “Palm oil is decimating South East Asia’s rich diversity of species as it eats into swathes of tropical forest. But if it is replaced by much larger areas of rapeseed, soy or sunflower fields, different natural ecosystems and species may suffer.” [17]

While palm oil is associated with more threatened species (321) globally than any other oil crop, other vegetable oils also threaten biodiversity. Soybean oil is associated with 73 threatened species and coconut with 66. With its relatively small production volume compared to other oils, coconut actually threatens more species per ton of oil produced than any other vegetable oil, followed by olive oil [18]:

There are also significant issues with rapeseed (canola) oil and its impact on bee populations, avocado oil causing environmental havoc in Mexico, and olive production resulting in the death of 2.6 million birds every year in Spain.

Nutrition

The cruel irony is that our planet pays a huge price in order to deliver us these oils, and they are devoid of nutrients. While many other food crops also contribute to species loss, deforestation, and greenhouse gas emissions, they at least bring us some nutrition.

Of all major food crops in the world, vegetable oils provide by far the least nutrition per kilogram, comparable only to sugar:

Vegetable oils account for up to 30% of global crop lands, but deliver less than 0.01% of the world’s important nutrients.

If we use nutrient-density as the denominator when looking at any of the above charts (e.g. emissions per nutrition, or land use per nutrition), vegetable oils are off-the-charts bad.

Sadly, even the vegetable oils that are perceived as better for health, like avocado and olive oil, have massive environmental and social issues.

Avocado oil, most of which comes from Mexico, is driven by poor working conditions and managed largely by cartels, which have been seizing farms and clearing protected woodlands to plant their own groves of avocado trees.

What’s worse, much of the avocado and olive oils purchased online and from store shelves are fraudulent and/or rancid.

In the case of olive oil, investigative journalist Tom Mueller found that “around 75 to 80 percent” of extra virgin olive oils sold in the U.S. are fraudulent, while the first extensive study of commercial avocado oil quality found that “at least 82 percent” of test samples purchased online and in stores were rancid or mixed with other oils like soybean oil.

While adulteration and toxic rancidity are unique to vegetable oils, all major food crops have environmental consequences, but some are better than others. Fruits and vegetables, for example, require significantly less land and emit significantly fewer greenhouse gases than most grains, nuts, and legumes.

Root vegetables in particular, which include sweet potatoes, turnips, parsnips, rutabagas, radishes, carrots, yams, and beets, are some of the most environmentally-friendly foods on the planet, producing the second fewest greenhouse gases and requiring the least amount of land per kilogram of food, while also faring pretty well in terms of nutrient density.

Similarly, there are certain food crops, primarily vegetable oils, that are not only devoid of nutrients, but also appear to be much worse for the environment, requiring large amounts of land, contributing to growing rates of deforestation, and emitting massive amounts of greenhouse gases.

Nutrient-sparse vegetable oils don’t just provide “empty calories” like iceberg lettuce or white rice; they are causally linked to disease and may be the largest driver of increasing rates of chronic diseases like heart disease and cancer, responsible for 7 of the top 10 causes of death worldwide [19].

While it may require some short-term environmental sacrifices to nourish a growing global population, we shouldn’t cut down our rainforests, threaten biodiversity, and accelerate climate change in order to grow foods that kill us.

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This is Part 4 in a series of posts investigating how vegetable oil impacts our health and our planet:

Part 1: What’s Driving Chronic Disease?

Part 2: Death by Vegetable Oil: What the Studies Say

Part 3: Why is Vegetable Oil Unhealthy?

Part 4: The Environmental Impact of Vegetable Oils (current post)

Part 5: Coming soon, sign up to stay informed

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