Part I

Cooling the Planet
One contributor to climate change is also essential to modern society. This is the story of the search for a sustainable alternative.

Part I

Cooling the Planet
One contributor to climate change is also essential to modern society. This is the story of the search for a sustainable alternative.

This is the first installment in a three-part reported series on the global effort to introduce more sustainable refrigerants. Click here to read Part II: Cold Warriors and Part III: The Future of Cool.

Nnaemeka Ikegwuonu comes from a family of farmers. In the fertile lands of southeast Nigeria, he and his children raise poultry, breed cattle, and grow fruits and vegetables.

But despite productive farms and harvests, most people in the region scramble to feed their families.

“Farmers lose 50 percent of their harvest due to spoilage,” says Ikegwuonu. “There’s no reliable electricity to keep food cool in storage at local markets.”

And while food is spoiling in the south, families are starving to death in the north. The UN has said that a potential famine in the region could prove to be the worst humanitarian crisis in 70 years, with more than eight million people at risk. The country’s current infrastructure and technological capabilities aren’t sufficient to link the two regions together.

The urgency of the issue pushed Ikegwuonu to look for a solution. In 2015, he launched Cold Hubs, which develops solar-powered refrigeration storage units. Today, there are 50 such units in southern Nigeria, and he hopes to have 100 by 2018, and 15,000 in the following decade.

The units have extended the shelf life of produce from two to 21 days, and the 150 local farmers who use the units have seen their income rise 25 percent. If technologies like Cold Hubs’ refrigerators were to spread across the country, countless families’ fortunes could drastically improve.

Nnaemeka’s story is just one example of how crucial cooling technology is to modern life.

And it’s not just playing a key role in developing countries, but across the globe. The transportation of food from farm to table, the delivery of vital medicines that fight diseases, the massive server farms that keep the digital world running, and our ability to safely inhabit the hottest regions, all rely on refrigerants to protect against withering heat.

But the very refrigerants we use to cool ourselves and life’s necessities can have an ironic and unintended side effect: they contribute to global warming and ozone depletion.

The irony of
keeping cool

To understand why, a little science is required. The compounds used to power air conditioners and refrigerators need to be chemically stable to be effective. But that means they have a longer lifespan, rising into the atmosphere after their job on Earth is done. Once they’re in the clouds, they contribute to the “greenhouse effect” that warms the climate. And when some of the older ones containing chlorine finally break down, they destroy the ozone layer.

A case in point was chlorofluorocarbons (CFCs). They seemed like the perfect refrigerants when they were first invented in 1928. “CFC 12 was a wonder molecule,” said Paul A. Newman, chief scientist for Earth Sciences at NASA’s Goddard Space Flight Center. “It wasn’t toxic. It wasn’t carcinogenic.” And it worked efficiently and effectively to cool our food and our lives.

But if left untethered, CFCs would have destroyed half of the ozone layer by 2045, and two- thirds by 2065, according to a study conducted by Newman and his colleagues at the Scientific Assessment Panel for the Montreal Protocol on Substances that Deplete the Ozone Layer. In mid-latitude cities like Washington, D.C., UV radiation would have been strong enough to cause sunburn in five minutes.

The world needed a coolant that was stable enough to work in air conditioners, refrigerators, and storage units, but not so stable that it damaged the Earth’s protective layers.

The hunt was on for a compound that struck the right balance.

How we
cool ourselves

Some turned to refrigerants like ammonia and CO2. They are still in use today, but widespread use is limited by toxicity, flammability and performance inefficiencies. In tropical climates, for example, some of these coolants aren’t efficient enough in oppressive heat and humid conditions.

CFCs were a much safer and more effective alternative, but the associated ozone depletion problems meant the search was still on.

A glimmer of hope surfaced in the late 1980s with the introduction of hydrofluorocarbons (HFCs). HFCs were powerful and efficient, and had no effect on ozone depletion. HFC use increased as developed economies like the U.S., Japan and EU carried out their transition from chlorinated refrigerants (CFCs and HCFCs) to meet their Montreal Protocol commitments. Even more significant HFC growth was expected in the future as growing economies in developing countries like China and India drove a demand for air conditioning and refrigeration in homes, cars and supermarkets.

But it was eventually found that while HFCs didn’t deplete the ozone layer, they still contributed to global warming. Once again, the technology that was protecting people from the elements and providing significant societal benefit needed to be further enhanced to minimize environmental impact.

A new kind of cool

Why one small change in how we chill our world could make all the difference

The global response

Recognizing the urgency of the issue and the need for a concrete plan to address it, the world community came together. After eight years of negotiations and discussions, a global summit was held in Kigali, Rwanda, in 2016. More than 150 countries agreed to the legally binding Kigali Agreement to phase down the use of HFCs.

While HFCs are still widely used and a critical part of many economies, the world is turning to better alternatives. Europe is leading the global charge with local laws like the F-gas regulation, which limits and, in some cases, bans the use of greenhouse gases with high global warming potential (GWP), and the EU MAC Directive, which regulates air conditioning systems used in light duty vehicles.

Progress in the U.S. has been mixed, but ultimately positive. Some states are adopting stricter measures than others, and executive branch messaging has shifted with administration changes. In California, for example, the Air Resources Board recently proposed a new strategy for phasing down HFC use to meet 2030 reduction targets.

Organs and medicine still needed to be transported to people whose lives were on the line, fresh produce still needed to be stored and shipped to those who were going hungry, and data centers still needed to be cooled. We needed a sustainable and effective answer.

The business sector has responded with an overwhelming vote of confidence for sustainability practices. Many corporate executives have issued renewed public commitments to action, while leading industry associations like the Air-Conditioning, Heating, and Refrigeration Institute have consistently supported regulatory frameworks that allow businesses to plan for the future.

In other countries, progress is being made but on different timelines based on agreed upon transitions from the Kigali Agreement. China promised to slow down HFC consumption starting in 2029, while India and Pakistan will start reducing consumption in 2028 to allow their economies more time to grow.

As the world aligned on regulations and laws to phase down HFCs, though, the need for a more sustainable alternative only grew more urgent. Organs and medicine still needed to be transported to people whose lives were on the line, fresh produce still needed to be stored and shipped to those who were going hungry, and data centers still needed to be cooled. We needed a sustainable and effective answer.


to the rescue

How long can each item below stay fresh without refrigeration?


How long does milk last without being refrigerated?

  • 2 hours
  • 4 hours
  • 6 hours


How long does insulin remain effective without being refrigerated?

  • 2 hours
  • 4 hours
  • 6 hours

Striking the
right balance

Auto manufacturers, chemical companies, and manufacturing suppliers began testing and development in earnest. SAE International, for example, held annual industry conferences in the early 2000s to organize tests among car makers, suppliers, and hardware manufacturers. The individual companies spent millions and tested every conceivable alternative.

Eventually, one contender rose to the top. Combining the best of both worlds, a hydrofluoroolefin (HFO), R-1234yf, maintained the performance of previous generations of refrigerants, with a low GWP and no negative impact on the ozone layer.

“We were looking for a refrigerant that we could use globally across a wide variety of conditions,” said Fred Sciance, of GM’s public policy center. “It needs to be compliant to global regulations, have the best balance of customer value, performance, and cost. R-1234yf is designed to perform at the level we needed.”

After rigorous industry testing, HFO production ramped up, and successful widespread adoption was underway. In mobile air conditioning, it is estimated that over 50 percent of the vehicles on the road will be using HFO-1234yf by the end of 2017, based on CO2 credits from the US EPA CAFÉ program.

If HFC growth is limited in the next three years and the transition to low-GWP alternatives continues, we could prevent up to 200 billion tons of CO2 equivalent emissions by 2050, according to the Institute for Governance and Sustainable Development. This could have a big environmental impact, lowering the predicted global temperature rise by 0.5°C by 2100.

Back in Nigeria, Nnaemeka is optimistic about the potential for his refrigeration units. In the coming years, he wants to expand the technology across Nigeria, boosting the income of the 70 percent of the country’s population that farms, addressing malnutrition and food insecurity, and even applying it to other fields like medicine and vaccines.

As the rest of the world expands its use of sustainable refrigerants, from cars to data centers to supermarkets and hospitals, the positive environmental and social impact will grow exponentially. Fresh food will be transported to famine-stricken families, life-saving medicine will be delivered to the sick, air-conditioning will cool those living in the hottest regions of developing countries. We have finally learned how to cool what we need to, without warming what we don’t.