The global cold chain relies on refrigerated containers to keep fresh products moving across continents. The Greener Reefer Transition Alliance developed a simulation tool that helps shipping companies and cargo owners comparing synthetic and climate-friendly systems using natural refrigerants, across real trade routes, showcasing how greener choices can not only reduce emissions but also be the better business choice.
More than 2,4 million refrigerated containers in 2018 are in operation worldwide with a 8% growth rate, transporting food and medical products across oceans. As maritime transport accounts for around 80% of global trade by volume, reliable refrigeration is essential to preventing losses, health risks, and economic damage. When refrigeration fails, up to 30% of perishable food can be lost, driving higher prices, waste, and unnecessary emissions.
At the same time, refrigeration itself has a climate impact. Refrigerated containers consume large amounts of energy and often rely on climate- and environmental damaging and ozone depleting refrigerants, contributing to emissions from a shipping sector responsible for about 3 % of global CO₂ emissions.
The importance of the cold chain becomes clear when looking at export-dependent economies. In Costa Rica, refrigerated logistics underpin exports of bananas, pineapples, and other fresh produce to North America and Europe. In 2024, the country recorded US$23.68 billion in exports, with agricultural goods alongside high-value optical and medical equipment—many of which also require controlled transport conditions. Any disruption to the cold chain would directly affect export revenues and global supply reliability.
A similar dynamic exists in South Africa, a regional export hub for citrus, grapes, apples, and other perishables shipped through ports such as Durban and Cape Town. Although the country’s exports—valued at approximately US$9.8 billion in 2025—are dominated by platinum, gold, vehicles, and chromium ore, cold-chain systems remain essential for agricultural exports. Precise temperature control over long distances is critical to maintaining product quality and meeting international standards.
Lower Emissions, Lower Costs: The Case for Natural Refrigerants
Natural refrigerants such as propane and CO₂ can significantly reduce the climate impact of refrigerated transport. Unlike many hydrofluorocarbons (HFCs), they have near-zero global warming potential and do not release PFAS (per- and polyfluoroalkyl substances), so-called “forever chemicals.”
Beyond environmental impact, greener reefers can reduce costs — especially by using natural refrigerants. But how significant are these savings, and how can they be quantified for real shipping routes? To support decision-making, the Greener Reefer Transition Alliance presented the new simulation tool "Reefer Emissions & Cost Saving Simulator" which helps shipping companies and cargo owners compare old vs. climate-friendly reefers across real trade routes.
In this webinar "From Emissions and PFAS to Earnings: The Case for Natural Refrigerants", we focussed on the economic case for switching to natural refrigerants in maritime refrigeration. Mark Major (Kuehne Climate Center (opens in a new window)) started the webinar by sharing the main idea and how the Greener Reefer Transition Alliance supports stakeholders in moving the maritime freight agenda into new horizons. Using the different examples of goods transported by reefers, Prof. Dr. Gordon Wilmsmeier, Director Center for Shipping and Global Logistics (CSGL), Kühne Logistics University (KLU), Germany and Kühne Professorial Chair in Logistics, Universidad de los Andes, Colombia showed how natural refrigerants can turn decarbonization into a strong business case, with different refrigerants affecting:
- Energy consumption and electricity costs
- Greenhouse gas emissions
- Total operating costs over a voyage
- The cost per kilogram of CO₂ avoided
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Simulation tool
Greener Reefers: making cold chains more sustainable
As demand for refrigerated transport grows, so does concern about its environmental footprint. The Greener Reefers project, implemented by GIZ Proklima, addresses this challenge in Costa Rica and South Africa. It is commissioned by the German Federal Ministry for the Environment, Climate Action, Nature Conservation and Nuclear Safety (BMUKN) in the context of the International Climate Initiative (IKI).
The project promotes refrigerated containers using natural refrigerants, such as propane and CO₂, which have a near-zero global warming potential compared to conventional HFCs. It also focuses on training technicians and operators, ensuring that cleaner technologies can be safely adopted and maintained.