Air-con is including to the local weather disaster. Nevertheless it doesn’t must be

November 20, 2021   |   by Noah Franklin

All of this must be done without leaving people behind. We already live in a world marked by climate change – fires, floods, rising sea levels, extreme rainfall and drought, loss of crops and forests (the lungs of our planet), and deaths and diseases from extreme heat. We must invest to strengthen our resilience to the forces we have unleashed.

However, as we learned from the COVID-19 pandemic, our resilience depends on that of our neighbors and communities. In extreme heat, regardless of our socio-economic status, we need air-conditioned and safe healthcare facilities; fresh food and medicines – especially vaccines during a pandemic – are safely stored and transported within a cold chain that often spans the world; and our homes, schools, and workplaces are cool enough that we can work efficiently and sleep peacefully.

Since extreme, often damp heat is developing more and more frequently, we are faced with a dangerous irony: The need for cooling is increasing, but the cold as we know it contributes through its energy requirements and the use of super pollutants. The coolants required for this, partially halogenated fluorocarbons, are a type of greenhouse gas that is even more harmful to the climate than carbon dioxide.

But there is a positive cycle, with concerted action that we can take locally and globally. First, let’s change the way we think about heating and cooling. For example, we have to systematically recover the waste heat from cooling, such as the hot air in the alley behind the local store or supermarket. It contributes to the heat island effect by trapping heat in our urban, built-up environment.

Then international cooperation can help. We need to remove extremely environmentally harmful partially halogenated fluorocarbons from refrigeration and air conditioning systems. Much depends on success in implementing the 2016 Kigali Amendment to the Montreal Protocol, which would phase out HFCs. The United States signaled earlier this year that action under Kigali is a big part of its climate protection.

Increasing resilience to climate change and greening have a global dimension. US manufacturers are leaders in non-fluorinated refrigerants, and as the need for refrigeration and refrigeration, especially overseas, grows, this presents an opportunity for American companies.

In addition, our focus must be on passive cooling. A Primer for Cool Cities report published by the World Bank focuses on reflective roofs, walls and walkways; Adding permeable surfaces to buildings – green roofs and walls – and permeable walkways; and adding more parks and treetops. Combine this approach with urban design solutions that maximize natural wind flow and don’t trap as much heat, and cities could stay cooler outside and inside.

Heat maps of cities, including Boston, show deep inequality in access to cooling. For many, access requires new technologies and business models that work on off-grid renewable energy systems. The market for inexpensive, environmentally friendly and highly efficient cooling and cooling is large and growing. To get a feel for the potential for innovation, just look at the finalists and winners of the Global Cooling Prize and the partnerships that emerged from the Chill Challenge. The Million Cool Roofs Challenge and Fair Cooling Fund provided financial support to communities in developing countries.

Inspirations come from urban forests in Melbourne, mobile green living rooms in Frankfurt and white roofs for low-income families in Ahmedabad, India. Closer to home, microgrids provide reliable, clean energy for cooling in communities like Chelsea, which can be combined with passive cooling solutions like greening and cool roofs for greater impact.

This summer many of us became aware of the number of “wet balls”. As a measurement that combines temperature and humidity into one value, it represents the point at which the water no longer evaporates from a wet thermometer ball. For humans, this is the point at which sweat, our cooling mechanism, can no longer cool us. When the wet-bulb temperature reaches 95 degrees Fahrenheit, it exceeds a threshold at which a person can no longer lose any internal body heat (at less than 95 degrees, serious health consequences can occur).

Climate scientists have warned us about the dangers of our carbon-intensive economic models for more than 40 years. Now, with incredible unanimity and clarity, they have said that we have one last chance to change and that if we do, we can slow down and then stop the damage we are doing.

Realizing the importance of being cool, we need to act and act now. A small contribution would be for meteorologists to equip us with knowledge by talking about the wet bulb number in addition to hints about heat, pollen and clean air and making them part of our daily thinking.

Rachel Kyte is the dean of the Fletcher School at Tufts University. She is an advisor to the UN Secretary General on climate and energy issues. Send comments to

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