Which cooking oil should I use to reduce my carbon footprint?

NEW YORK – A splash here, a splash there. You might not think your cooking oil matters much for the climate and the environment. But it does.

Farming accounts for about one-third of global carbon emissions. And, according to a major study published in 2022, nearly 20 per cent of the planet’s total farmed land goes towards oil crops.

But that does not mean that all oils are bad. Some are much better than others. And, in some cases, they might even provide a net benefit in terms of planet-warming carbon.

Here, in a nutshell, is what you should know.

The global rankings

Just four crops make up more than 85 per cent of the world’s edible oil: palm, soya, canola and sunflower.

Peanut, coconut and olive oils are the next biggest. All the others, including corn, grapeseed and avocado, make up just a sliver of the global market.

According to that 2022 study and another recent assessment, canola and sunflower oil are the two best bets for the climate, on average, around the world.

After those, the top tier looks something like this, from best to worst: olive, coconut, soya and peanut.

Soya loses points because so much is grown on deforested parts of the Brazilian Amazon. Peanut and coconut oils also have high land costs.

Palm oil is rarely used for cooking in the United States and Europe, but it is found in countless consumer products. Its environmental effects depend hugely on where the oil was produced. The problem is, it is often difficult or impossible to know where the palm oil in your chocolate bar, lipstick or soap came from.

The six major oils fall in a slightly different order when biodiversity is the main consideration. From best to worst by that measure, omitting palm, the top ranking goes to sunflower. Olive and canola are in a near tie for second place, followed by soya and coconut in another near tie, and last, peanut.

But there is more: Location matters.

Global averages are a good guide, but oils can have a very different environmental footprint depending on where they came from and where you live.

A case in point: those ubiquitous bottles in US shops labelled “vegetable oil”.

What does that mean? It is “usually soya bean oil”, said Dr Eric Decker, a professor in the department of food science at the University of Massachusetts Amherst.

Check the label and it might show a blend, commonly of soya and corn, though sellers are not required to provide a breakdown.

But most major brands – including Wesson Vegetable Oil, Crisco Pure Vegetable Oil, Walmart’s Great Value brand, Target’s Good & Gather brand, and Lowe’s 100% Pure Vegetable Oil – show soya oil as the only ingredient.

Crucially, nearly all of this oil is grown in the United States, according to the American Soybean Association, a non-profit group that advocates on behalf of farmers.

And the 2022 study found that US-grown soya is associated with relatively low carbon emissions. That makes vegetable oil one of the top environmental options in the United States, as long as it is pure American-produced soya.

Canola can also be a good choice, but its origins matter too.

The soil of the prairie ecozone where almost all North American canola is farmed has “a relatively low storage potential”, said Dr Stephen Ramsden, an agricultural economist at the University of Nottingham in England who was an author of the 2022 study.

That means using the land for agriculture does not represent a big loss of carbon-storage capacity. “You’re not really giving up that much,” he added.

That gives canola its edge. In fact, according to the study, canola from these native grasslands is the only oil that can have net negative emissions, meaning it absorbs more planet-warming carbon dioxide from the atmosphere than its production generates.

An important note: Canola earns a top-tier rating only when the soil is not tilled. When farmers till, turning the soil over and releasing carbon, the oil’s related emissions more than double.

As with soya, those in North America can probably rest easy if they are buying canola grown there. Around two-thirds of the farmland in question is no-till, and 90 per cent is at least low-till, according to the US Canola Association and Canada’s national statistics agency.

The name, by the way, is derived from “Canadian oil, low acid”. In Europe, it is called rapeseed oil.

Canola oil is also one of the healthiest oils to cook with because, among other things, it has the lowest saturated fat content of any oil.

Understanding cooking oil in the rest of the world, where it tends to be sourced from more places, is more difficult. To be safe, stick with canola, sunflower and olive oils.

Reducing oil use

Ultimately, to decrease the environmental footprint of the oil in your life, you can try to eat less processed food, do not go overboard on cosmetics and use oil sparingly when you cook.

One of the biggest advantages of plant-based oil is simply the fact that it is plant-based.

“We need to get the calories from somewhere,” said researcher Robert Beyer, who helped write a major oil comparison study while at Cambridge University.

“If you reduce vegetable oils, and suddenly everybody starts cooking with butter or goose fat or something, environmental impact will definitely go through the roof.” NYTIMES