From Miami to Melbourne, a quiet revolution is underway

A quiet revolution is now underway to address a widely underappreciated climate challenge: extreme heat.

Local authorities have appointed several Chief Heat Officers (CHOs) in cities around the world in recent years to prepare residents for frequent and severe bouts of excessive heat.

“They call him the silent killer,” said Eleni Merivelli, who serves as global coordinator for the United Nations Human Settlements Programme, and previously worked in a similar role in the Greek capital, Athens.

Merivelli said she believes extreme heat is often overlooked because it lacks the visual drama of ripping roofs off homes or turning streets into rivers.

“I think heat, from the bottom of my heart, is going to be the number one public health challenge that we're going to deal with in the next decade. And we have to prepare for that now,” Merivelli told CNBC via video. “We can, but we really need to make it a priority.”

Heat is the leading cause of weather-related death in the United States. Data from the Centers for Disease Control and Prevention showed that more than 1,700 deaths were due to heat-related causes in 2022, nearly double the number of deaths five years ago. These are likely conservative estimates, the researchers said.

The CDC defines extreme heat as summer temperatures that are hotter and/or wetter than average.

Older adults, young children, and people with chronic diseases are among those most at risk for heat-related illness, such as heat exhaustion or heat stroke. The CDC warns that even young and healthy people can be affected.

The first person in the world to be appointed CHO was Jane Gilbert, who was appointed in 2021 to oversee Florida's most populous Miami-Dade County.

The CHO role was created through an initiative of the Adrienne Arsht-Rockefeller Foundation's Resilience Center (Arsht-Rock), a US-based think tank that aims to support 500 million people with heat resilience solutions by 2030.

“We have relatively high (air conditioning) penetration, but as our temperatures rise, our electricity bills are through the roof. Our electricity prices have also gone up. The price of an air conditioner can add up to more than 50% of their electricity bill so people can “They're choosing between air conditioning and putting food on the table for their families,” Gilbert told CNBC.

Miami, a coastal city located in the southern United States, is known globally for its vulnerability to sea level rise and hurricanes. However, community-led surveys have identified chronic heat as the most pressing climate concern, Gilbert said.

For six months of the year, Gilbert said temperatures in Miami exceed 90 degrees Fahrenheit (32.2 degrees Celsius) almost daily, which poses a particularly big problem for outdoor workers.

To help reduce risks to the province's 2.7 million residents, Gilbert said her team's action plan focused on informing and preparing people for extreme heat, helping cool homes affordably, and working to cool community neighborhoods to address the so-called “heat island effect.” . “- as the city experiences warmer temperatures than neighboring rural areas.

In practice, Gilbert said the actions included extensive marketing campaigns targeting ZIP codes and demographics known to be most at risk, and working with the National Weather Service and emergency management teams to update advisory and alert levels. It also included installing 1,700 efficient air conditioning units in public housing and ensuring that new affordable housing requires the most efficient cooling systems, such as cool and solar-ready roofs, to keep utility costs down.

“We want to address the root cause of this problem while helping people adapt,” Gilbert said.

“We all grew up here in a typically hot and humid environment,” Bushra Afreen, operations manager for Dhaka North, Bangladesh, told CNBC. “We are used to the heat, which makes it really difficult to differentiate between normal heat and unsafe heat.” Via video conference.

Afreen, who became COO of Dhaka North in May last year, said the stark income disparity in the country's largest city means extreme heat is not a similar experience globally.

“When you combine that with fragile urban systems like sanitation, power outages, poor health management, poor health systems, poor education systems, you get a very bad soup.”

Besides planting thousands of trees in informal settlements in Dhaka North and reintroducing water fountain culture in the city, Afreen said her team will launch a pilot project in a settlement in a city to create green nooks and crannies to mitigate the effects of disasters.

Afreen said it would be important to consider what type of trees would be planted, such as citrus or neem trees to ward off mosquitoes amid the dengue outbreak. She added that it will also be necessary to provide adequate lighting, a bench, surveillance cameras, a water fountain and signs urging priority for women and children.

“Right now, the reactions we're seeing the most are: 'Good job, keep it up, we need more awareness,'” Avrin said.

The other type is: “Oh, are you going to turn down the heat?” good luck”.”

Extreme heat kills more people in Australia than bushfires, floods and storms, Tiffany Crawford, Melbourne's deputy director of operations, told CNBC.

“There is a reason for this, which is the lag in the data,” she said.

Crawford, who works alongside Christa Milne as Melbourne's health director, said the true scale of heat-related deaths and illnesses often does not become clear until health authorities study hospital admissions and ambulance data.

The city of Melbourne in southeastern Australia, with a population of about 5 million, is known for its mild climate, but Crawford says it is vulnerable to summer heatwaves that last for days and provide little relief at night.

“There's a strong north wind blowing really hard. I liken it to being outside, like someone left the oven door open or the heater on all night and forgot to turn it off,” Crawford said.

Some of the short-term interventions implemented in Melbourne include extending public library and pool opening hours and rolling out so-called cool kits, which contain water bottles, neck towels and old-fashioned fans.

Looking to the future, Crawford said the city is in conversation with Google to provide voters with so-called “cool routes” mapped online, which help users navigate the city by taking advantage of existing shade or canopy cover.

“In places like Europe, the dialogue in the media is a little different, and the heat is shocking. Whereas in Australia, heat is something we've been constantly living with, and will continue to live with, but these are those variables. Like any climate response,” Crawford said. “It became clearer.”

“We need to plan for that.”