How Aldi is Tackling Extremely Potent Greenhouse Gases

As part of its efforts to reach net-zero carbon emissions by 2050, the retail grocery chain Aldi is eliminating its use of refrigerants that contain hydrofluorocarbons (HFCs) across its value chain. Aldi aims to stop using HFCs by 2035.

HFCs are extremely potent greenhouse gases. Commonly used in air conditioning and refrigeration systems, like cold storage in grocery stores, they can trap thousands of times more heat in the atmosphere than carbon dioxide. 

“At Aldi we’ve recognized that we have a huge responsibility addressing climate change, and still, obviously, providing affordable groceries to our customers. In doing so, we evaluated our greenhouse gas emission reductions and set really ambitious targets,” Amber Hardy, the director of systems and sustainability at Aldi USA, told TriplePundit. “Refrigeration is a huge contributing factor in emissions in retail grocery stores. That is essentially where some of these commitments have come from: our aim to target our annual reduction measures.”

To date, more than 700 Aldi stores use natural refrigerants, including carbon dioxide and propane. The grocery chain’s warehouses use ammonia as a refrigerant, Hardy said. Natural refrigerants have a much lower impact on global warming than HFCs and are currently considered the most climate-friendly alternative. 

“As one of the fastest growing retailers in America right now, we continue to make adopting natural refrigerants a priority in those growth plans,” Hardy said. “We’ve planned to continue buying all natural refrigerant systems for new and remodeled stores, and in doing that, we plan to replace all existing systems with those low global warming refrigerants.”

The use of HFCs increased globally after the Montreal Protocol, the international agreement adopted in 1987 to protect the ozone layer, which was being depleted by the use of chlorofluorocarbons. HFCs replaced chlorofluorocarbons under the protocol because they don’t contain chlorine, which destroys the molecules that make up the ozone layer.

Compared with greenhouse gases like carbon dioxide, HFCs remain in the atmosphere for much shorter periods of time. But while in the atmosphere, HFCs have a much larger impact on global temperatures than carbon dioxide. HFC-134a, a common refrigerant, is the most abundant hydrofluorocarbon in the atmosphere and has a global warming potential of about 1,430. In other words, it traps 1,430 times more heat in the atmosphere than an equivalent amount of carbon dioxide. Under the Kigali Amendment, 160 countries — including the United States — committed to cutting the production and consumption of HFCs by more than 80 percent during the next 30 years.

In addition to switching to natural refrigerants, Aldi is rolling out a building management and control system that will improve how the grocery chain operates its refrigeration systems on a day-to-day basis and reduce refrigerant leakage, Hardy said. 

“This is a huge piece of that puzzle, better controlling our systems and monitoring them,” Hardy said. “It helps us identify if we have risk for food spoilage that contributes to our waste stream.” 

The natural refrigerant used depends upon the climate where stores are located, she said. 

“We actually have strategically adopted natural refrigerants in some of the easier climate zones first, so there’s several in northern climates,” Hardy said. “When we moved into the California market, we went in immediately with a natural refrigerant carbon dioxide design. Knowing that the regulatory environment was, it was the right decision for that market.”

Aldi set carbon dioxide natural refrigerant systems as the standard for northern climates, primarily because carbon dioxide performs better in colder conditions, Hardy said. From there, the grocery chain began selecting sites across the country — typically new locations or those undergoing major remodels — to implement the natural refrigerant solution tailored to each climate.

In regions with high heat and humidity, such as South Florida, Aldi uses propane as a refrigerant but has been able to adopt carbon dioxide as a refrigerant in some southern climate zones as well, Hardy said. 

“Operating in 2,400 stores across 38 states, we need to find the right solutions for each market and climate,” Hardy said. “We work closely with our refrigeration partners to bring them on board with this new technology, which has presented some challenges, particularly around training and adoption. However, we’ve proven it’s possible.” 

Hardy cited one of Aldi’s first southern stores to adopt carbon dioxide as an example. Located in Decatur, Georgia, it earned a recognition of excellence from the U.S. Environmental Protection Agency for five years as a certified GreenChill store, meaning it uses an environmentally friendlier commercial refrigeration system. The store demonstrates that southern climates can successfully adopt natural refrigerants.

“We anticipate that as we continue leading the industry in emissions reductions, we’ll see similar buy-in, adoption, and reduction measures across our value chain. Our goal is to have all our suppliers engaged in carbon emissions reduction programs by 2050,”  Hardy said. “It’s critical that our environmental footprint doesn’t grow alongside us.” 

Editor's Note: An earlier version of this story indicated that Aldi's plan to eliminate HFCs would reduce its emissions by 60 percent. In fact, the stores already using HFC alternatives contribute to reducing Aldi's potential emissions by 60 percent per year. This story was updated on January 5, 2025, to correct the error.