07/22/2022
"The cooling problem" By Somini Sengupta, Global Correspondent, Climate
FROM: New York Times Climate Forward
"Air-conditioners are a lifesaver — and a culprit. Yes, they are vital in times of deadly heat. But they’re also an important source of greenhouse gases and a prime example of how global warming is unfair.
In today’s newsletter, I’ll explain why it’s crucial to improve cooling and how we can do it. Many fixes are already within reach.
One 2019 research paper estimated that between 1.8 to 4.1 billion people may need air-conditioning to avoid heat-related stresses under current conditions but do not yet have access. In Africa, where more than half the population lives in a hot climate, only 5.6 percent have an air-conditioner.
There are also almost 1 billion people worldwide who don’t have electricity at all. So, no fans either.
As Radhika Khosla, co-director of the Future of Cooling program at the University of Oxford, told me, “equity is a central issue to the future of cooling.”
Meanwhile, those of us who can afford air-conditioners are using them much more on these intensely hot days. That’s sharply raising demand for electricity.
Air-conditioners have other problems. They spew hot air outside, making the surrounding area hotter. And, they use dirty refrigerants. Cooling is one of the fastest growing sources of greenhouse gas emissions, destined to grow especially fast in developing countries.
There are ways to improve cooling and make it more fair. They would not only make heat waves less oppressive, they could even make our communities more livable.
There are many ways, old and new, to reduce or eliminate altogether the need for air-conditioning inside buildings. Architects and urban planners are trying many of these things already.
A museum in Rio de Janeiro draws in water from a nearby bay for cooling. Similarly, but at a bigger scale, Toronto’s downtown core has a cooling system that uses cool lake water to absorb heat from city buildings. A hospital in rural Bangladesh uses courtyards and canals to create a cooling microclimate. Architects in Singapore, the air conditioning capital of Southeast Asia, are angling buildings in ways that allow wind to flow through city blocks and using vertical gardens to cool high-end hotels and office buildings.
And then, there’s paint. Researchers are competing to develop white paint that reflects nearly all sunlight. The ones in use now still absorb around 15 percent of sunlight and the heat that comes with it.
Efforts to cool city neighborhoods aren’t always immediately popular. In Paris, a plan to cool the area around the Eiffel Tower is facing fierce opposition because it means knocking down trees, as my colleague Constant Méheut wrote.
Now more than ever, energy-saving innovations are needed. The Toronto cooling system saves enough electricity to power a town of 25,000 through a year, while the Rio museum’s cooling system consumes 50 percent less energy than a conventional one. In fact, a recent United Nations report estimates that a global, coordinated effort to make cooling more sustainable and efficient could avoid eight years’ worth of global emissions, based on 2018 levels, over four decades.
The Rocky Mountain Institute, a research group whose Colorado-based office generates more energy than it consumes, runs a competition to spur innovations in cooling. The two companies that won last year, Daikin and Gree, developed air-conditioners that use much less energy.
Why doesn’t every company do that? Electricity standards don’t require it yet, explained Iain Campbell, a cooling expert at the Rocky Mountain Institute, . Plus, it’s more expensive upfront. The prototypes developed by the two companies were two to three times pricier, Campbell said. “But over 10 years, using these machines would cost you half,” he added. They would simply use less electricity.
The average efficiency of air-conditioners sold in the market now, Khosla said, is typically one-third of the most efficient technology available.
Some hydrofluorocarbons that are used in most air-conditioners, known as R134a or R404a, are like greenhouse gases on steroids. They warm up the Earth’s atmosphere much more than, say, carbon dioxide. So, as more people buy air-conditioners, Khosla points out, “a new source of global temperature rise is essentially being introduced.”
Alternative refrigerants are out there, according to the European Commission, which has its own regulations to reduce the climate impact of air-conditioners. To scale up adoption globally, governments will need to urge their use, in order to protect the health of their people.
