The way you dispose of old kitchen appliances and air conditioning units can have a huge impact on the climate.

Whether you are a farmer in Kenya transporting milk to the local market, the owner of a London cornershop or a patient undergoing chemotherapy in Japan, we all rely on devices that keep us, and the things we consume, cool. Without fridges our food would quickly go off, milk would rapidly sour and food poisonings would likely skyrocket.

In the coming months, refrigeration is likely to play a vital role in the current pandemic too. As vaccines begin to roll out, they will need enormous cold-storage supply chains for them to be manufactured, distributed and stored until they are administered. Many other life-saving medications – from insulin to antibiotics – also need to be stored in this “cold-chain” to prevent them from degrading and becoming useless.

In schools, offices, shops and homes in many parts of the world, refrigerants also play an important role in the air conditioning systems that keep these buildings comfortable.

The cooling industry is important, but it is also incredibly polluting – accounting for around 10% of global CO2 emissions. That is three times the amount produced by aviation and shipping combined. And as temperatures around the world continue to rise due to climate change, the demand for cooling will increase too.

With countries and companies under pressure to slash their contribution to climate change, the cooling industry is facing a radical overhaul to the way it produces and disposes of refrigerants. Over the past three decades, governments around the world have pledged to crack down on the potent climate-warming chemicals used as coolants, while companies have started seeking natural, less polluting alternatives. But environmental campaigners say changes must be made much faster if international climate goals are to be met.

Consumers too can play their part through the devices they buy, how they use them and what they do with refrigerant-filled equipment once finished with them.

But what is it about refrigerants that makes them so bad for the climate?

Refrigerators and air conditioning units certainly use a fair bit of energy, especially when they are running continuously in hot climates. But they also contain chemicals that readily absorb heat from the environment as they turn from being a cool liquid into a gas. As they transition back to liquid, they release the heat into the outside – either outside a building or outside a fridge – before being cycled back to begin the cooling process again.

These same chemicals are also used in some types of insulation foam and as the propellant in aerosol spray cans.

Their capacity to warm the atmosphere is thousands of times greater than carbon dioxide, with some being up to 11,700 times more potent

The most common type of refrigerant used to be chlorofluorocarbons, more widely known by their acronym CFCs. But after CFCs were found to be depleting the ozone layer, there was a worldwide effort to phased them out. The 1987 Montreal Protocol – a landmark environmental agreement signed by over 200 countries – means these environmentally harmful chemicals are no longer produced.

But the effort to get rid of CFCs resulted in many chemical manufacturers choosing to replace them with two groups of chemicals with a different problem – hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs). These refrigerants do not break down ozone molecules, but are instead extremely potent greenhouse gases. Their capacity to warm the atmosphere – measured as global warming potential – is thousands of times greater than carbon dioxide, with some being up to 11,700 times more potent. This is because HFCs and HCFCs – and to a lesser extent CFCs – trap heat inside the atmosphere rather than allowing it to escape back into space, creating a greenhouse effect that warms the planet.

Although these chemicals are used for a number of different purposes, by far the largest source of emissions is from refrigeration and air conditioning systems. Over time they can leak out into the atmosphere from damaged appliances or from car air conditioning systems, for example.

“The industry as a whole has had a huge impact on global warming,” says Clare Perry, senior campaigner at the Environmental Investigation Agency (EIA), a non-profit that investigates and campaigns against environmental abuse. She says taken together CFCs, HFCs and HCFCs have accounted for close to 11% of total warming emissions to date.

In 2016, officials from over 150 countries signed the Kigali Amendment, agreeing to reduce HFC consumption by 80% by 2047. If achieved, this could avoid more than 0.4C of global warming by the end of the century – a sizeable amount in our efforts to reduce the effects of climate change.

As HFCs are potent gases that can remain in the atmosphere for up to 29 years, there is an urgent need to phase them out, says Doug Parr, chief climate scientist at Greenpeace. “Once they are produced, they are problematic to deal with. You’re building a problem bank of chemicals,” says Parr.

But industry experts say these harmful refrigerants are still widespread and increasing rapidly due to a global surge in demand for air conditioning, sluggish innovation from industry and inadequate legislation around their disposal. All around the world, the demand for air conditioning is growing as temperatures rise and people become wealthier, according to the International Energy Agency (IEA). Recent heatwaves in Europe have also driven sales of air conditioning in areas where they were previously uncommon.

The number of global cooling devices is estimated to increase from 3.6 billion to 9.5 billion by 2050, according to a report by the United Nations Environment Programme (UNEP) and the IEA. Providing cooling to everyone who needs it, and not just those who can afford it, will require 14 billion devices by 2050, the report notes.

“As countries in the global south are starting to increase their wealth, their ability to purchase air conditioners and refrigerators is increasing dramatically,” says Brian Dean, head of energy efficiency and cooling at the UN-backed initiative Sustainable Energy for All.

Without radical changes to the cooling industry, HFC emissions are projected to contribute warming equivalent to 20% of CO2 output in 2050, the UNEP report warns.

Roughly 90% of refrigerant emissions occur at equipment’s end of life

There are ways to cool a home without the need for air conditioning. Traditional approaches use water features such as fountains to help cool the air passing through a building, while others use careful design to encourage natural air circulation. Even simple approaches like placing an earthenware pot of water near a window or drafty spot can help to cool a room by a few of degrees. (Read more about how to cool your home without AC.)

Part of the problem with refrigerants, however, is that much of the harm they cause is after we as consumers have finished using them. It occurs out of sight, and so largely out of mind.

Roughly 90% of refrigerant emissions occur at equipment’s end of life, according to Project Drawdown, a nonprofit that analyses climate solutions. This means that proper disposal is essential. If the refrigerant chemicals are carefully extracted and stored, they can be purified for reuse or turned into other substances that do not cause global warming.

Proper management and reuse of potent refrigerant gases could slash 100 billion gigatons of global CO2 emissions between 2020 and 2050, according to the EIA. But proper disposal of HFCs is not a mandatory requirement under the Montreal Protocol and is not properly enforced in many countries, according to UNEP.

The most common HFC found in domestic fridges is HFC-134a, which has a global warming potential 3,400 times that of carbon dioxide. A typical fridge can contain between 0.05kg and 0.25kg of refrigerant, which if it leaks into the environment, the resulting emissions would be equivalent to driving 675km-3,427km (420-2,130 miles) in an average family-sized car.

Consumers looking to get rid of their old fridge, freezer or air conditioning unit in a responsible fashion have a number of options open to them. In the US, old appliances can be disposed of through schemes approved by the Environmental Protection Agency. Many local authorities will pick up and recycle old appliances, while manufacturers and retailers of new devices often offer to take away the old item. Efforts to phase out HFCs in the US have been added to the recent energy innovation bill that is currently going through the Senate.

In the European Union, legislation already requires HFC gases to be recovered at end of life to prevent them from leaking into the atmosphere. If your fridge breaks in the UK, for example, you are required to take it to a licensed waste facility where a technician removes the gas. It is illegal to not reclaim the refrigerants before destroying an appliance.

But a recent study found that global emissions of HFC-23, which has the highest global warming potential of all HFCs, reached an all-time high in 2018 despite international efforts to reduce their use, suggesting that a large amount of gas is not properly recovered at end of life.

In many countries there are no proper regulations in place. This is especially a concern in developing countries, according to Dean.

“If [people] decide to keep [their appliances] and maybe smash them in the backyard, there's no regulatory mechanism that stops individuals from not disposing of refrigerants properly,” he says.

In some cases HFCs are also finding their way into products illegally, which is threatening to undermine efforts to phase them out. Following new regulations introduced by the European Union in 2014, prices of HFCs have soared. But the EIA claims there are discrepancies in export and import data of HFCs leaving China and arriving in the EU. In the second half of 2019, 54 tonnes of HFCs were seized, a ten-fold increase compared to the same period in 2018, according to unpublished analysis by EIA.

According to Perry, ineffective enforcement is allowing large-scale illegal HFC trade and some of these may end up in devices sold to consumers. "Probably the highest risk for your average consumer is that illegal HFCs could be used to service the air-conditioning in your car, she says. "So it’s worth asking your service garage how they ensure that the HFCs they use are from a reputable source."

Manufacturers have started turning to climate-friendly chemicals, known as natural refrigerants, which have comparatively low or zero global warming potentia

The chemical industry is taking steps to stop illegal trade in HFCs and consumers can find out which companies have pledged to take action on a website they set up. But more needs to be done, says Perry.

“If the illegal trade continues apace it will threaten the integrity of the HFC phase-down and EU climate targets,” she says.

For those already looking to replace their fridge or air conditioning unit with something that is better for the planet, there are a growing number of options available. Manufacturers have started turning to climate-friendly chemicals, known as natural refrigerants, which have comparatively low or zero global warming potential.

Major global brands such as Coca Cola, PepsiCo and Unilever have set goals to phase out HFCs and already started using alternatives. Ammonia, certain hydrocarbons and CO2 are the most popular options.

Coca Cola has pledged that all new cold drinks equipment it uses will be HFC-free and has already switched to using the hydrocarbon propane in many of its vending machines. Unilever ice cream brands, including Ben & Jerry’s and Wall’s, also use hydrocarbons in their freezers.

Most supermarkets in Europe now use CO2 in their fridges and freezers after EU regulations to phase out HFCs were introduced in 2015.

But safety concerns are hindering an industry-wide transition towards natural refrigerants. Ammonia, for example, is highly toxic meaning it would present a health risk should it escape through a leak while propane is a flammable gas. But relatively small amounts of these chemicals are needed in the sealed tubes that circulate them around fridges and air conditioning units.

Environmental campaigners say chemical manufacturers are also resisting the shift to these natural substances.

“They cannot patent CO2, hydrocarbons or ammonia because they are natural substances,” said Marc Chasserot, who founded Shecco, a market accelerator for natural refrigerants. “They will tell you that they are dangerous, [but] no Coca Cola vending machine using hydrocarbons has ever blown up. The flammability risk can be managed very easily,” he claims.

US chemical manufacturer Honeywell has invested in hydrofluoroolefins (HFOs) instead of natural refrigerants, producing a patented chemical called HFO1234yf. “In many applications, these solutions have a global warming potential that is equal to, or better than, carbon dioxide and as much as 99% lower than other HFC technologies,” says George Koutsaftes, Honeywell’s president of advanced materials.

But Perry says these substances are not long-term solutions as they produce toxic acid as they break down in the atmosphere which pollutes groundwater. “Natural refrigerants are the only [ones] that are basically future proof,” says Perry. “The phase out is going to continue and only be strengthened, [making potent refrigerants] more and more rare and expensive, and eventually illegal.”

Some countries have already introduced labelling to help people easily identify which fridges contain these more climate-friendly alternatives

One company that has committed to phasing out HFCs is Mabe, a major Mexican manufacturer that distributes appliances to over 70 countries. It has announced that it will completely phase out HFCs from its 11 production plants this year, replacing them with hydrocarbons.

“We want the world to know that the transition to new refrigeration alternatives is possible,” explains Pablo Moreno, Mabe’s head of corporate affairs. He claims the move could reduce the company’s CO2 emissions by 240,000 tonnes per year. Another manufacturer, Electrolux, has pledged to remove all HFCs from its fridges and freezers by 2023.

For consumers, however, working out which appliances contain natural refrigerants is not always easy. Some countries have already introduced labelling to help people easily identify which fridges contain these more climate-friendly alternatives.

But with so many HFCs sitting in kitchens and air conditioning systems around the world already, our desire to stay cool could make the world a lot hotter.