When Hurricane Ida hit Louisiana with catastrophic flooding and high winds in August 2021, more than 1 million people Loss of energy. Then came the heat wave. Temperatures soared above 90 degrees Fahrenheit — a terrible blow to those who were sweltering in their homes, unable to turn on their air conditioning as power outages stretched on for days.
It was the heat that proved to be the deadliest in New Orleans, responsible for at least nine of the city’s 14 hurricane-related deaths.
The combination of a hurricane, heat wave and multi-day power outage is a nightmare scenario, but it is expected to become more common as humans continue to heat the planet, fueling devastating extreme weather. And it reveals an uncomfortable truth about the vulnerability of humanity’s ultimate protection against heat: air conditioning.
The air conditioning is far from perfect. It devours energy, most of which still comes from planet-warming fossil fuels, meaning it exacerbates the very problem it is used to mitigate. Furthermore, it is only available to those who can pay, further increasing social inequality.
But it’s also a lifeline against increasingly brutal heat, the deadliest type of extreme weather. Allows people to live in places where temperatures come close to the limits of survivability and where extreme heat persists even at night.
Demand for AC is exploding, expect to triple across the world by 2050 as global temperatures rise and yields rise.
The problem is that, without electricity, you lose access to air conditioning. And many power grids are being pushed to breaking point due to increasingly frequent extreme weather conditions and growing demand for cooling.
Climate was responsible for 80% of major power cuts in the U.S. between 2000 and 2023, according to a report by Climate Central, a nonprofit research group. “Every aspect of climate is affecting the already vulnerable grid and really testing it,” said Jen Brady, senior data analyst at Climate Central.
In the U.S., the aging grid was designed “for the climate of the past, not the climate of the future,” said Michael Webber, a professor of mechanical engineering at the University of Texas at Austin.
The main threat is storms, which can knock down transmission wires and poles. But the heat is also having an impact. If it is too hot, the system works less efficiently. Webber likens it to how someone would feel running a marathon in the heat – “we just collapsed.” The grid can also buckle under the weight of demand as everyone turns on their air conditioning at the same time to deal with high temperatures.
The number of major outages in the U.S. — which affected more than 50,000 customers and lasted at least an hour — doubled between 2017 and 2020, said Brian Stone Jr., a professor specializing in urban environmental planning and design at the Georgia Institute of Technology. “Most of the increase is during the summer months, which tells me these systems are not resilient,” he told CNN.
Rising demand for cooling during an August 2020 heat wave in California led the state’s main grid operator to cut power to hundreds of thousands of homes in continuous blackouts for the first time in 20 years.
In 2021, during the scorching heat wave that scorched the Pacific Northwest, power equipment gave way to the heat, triggering rolling blackouts for tens of thousands of people as temperatures rose. above 100 degrees Fahrenheit.
It’s not just the US that’s in trouble. In June, when temperatures in southern Europe surpassed 104 degrees Fahrenheit, parts of Albania, Bosnia, Croatia and Montenegro experienced hours-long blackouts as electricity demand soared.
Even short power cuts can be dangerous. “If the grid fails while there is a heat wave, it goes from uncomfortable to deadly very quickly,” Webber said.
Heat can affect vital organs and cause heat exhaustion, heatstroke, and even death. If the power goes out when it’s really cold, people can add layers, build fires and huddle together. “If it gets too hot, there’s only one way to cool it down: with electricity,” Webber said.
The combination of a heat wave and power outages “is the deadliest weather event we can imagine,” Stone said.
He and a team of scientists explored the potential impacts of a heat wave coinciding with a multi-day outage caused by extreme weather or a cyberattack. Focusing on Atlanta, Detroit and Phoenix, they looked at exposure inside people’s homes, a leading cause of heat-related illnesses during a power outage.
The numbers were particularly harsh for Phoenix. During a heat event and a three- to four-day outage, half of the city’s population — nearly 800,000 people — would require hospital treatment for heat-related illnesses, according to the discoveries. More than 13,000 would die.
A power outage in Phoenix causes a “very dramatic change in heat illness,” Stone said, because the city’s climate is so extreme and people struggle to adapt. In an unfortunate irony, widespread air conditioning may actually make residents less resilient because they are so used to cooling in their homes and workplaces, Stone said.
Phoenix officials say the city is well prepared. Kate Gallego, the city’s mayor, said Stone’s research was based on an extremely unlikely scenario. “The study does not take into account any existing emergency response plans, nor the fact that our electrical grid is consistently ranked among the most reliable in the country,” Gallego told CNN.
Arizona Public Service, one of the utilities that provides power in Phoenix, said it has robust plans to avoid large-scale outages and regularly maintains the grid.
But while the chances of a combined multi-day power outage and heat wave in Phoenix may be low, Stone said, it is still possible and becoming more likely as the climate crisis worsens.
Drastically reducing planet-warming pollution is the best long-term defense against heat and extreme weather, but the world is already committed to several decades of rising temperatures, Stone said.
In the short term, there are ways to limit vulnerabilities.
Making the network more robust and resilient is one of them, Stone said. This includes repairs and upgrades that take future climate into account. Expanding and modernizing the grid, including adding more power plants and securing a diverse range of energy sources, will also help strengthen it, Webber said.
“But we also need to recognize that these networks will fail, and are failing more frequently, and so we need to have backup plans,” Stone said.
This means rethinking cities, where concrete, steel and asphalt, which retain heat, have replaced trees. Designing urban areas to be greener and cooler “can actually increase grid resilience without investing in the grid itself,” he said.
Climate Central’s Brady pointed to community solar projects, which can keep local power on when the grid goes down. Babcock Ranch in Florida – “America’s first solar-powered city” – managed to keep the lights on in 2022 when Hurricane Ian passed, unlike nearby cities.
Making homes more efficient will also help, Webber said. Homes better adapted to extreme weather conditions can help reduce electricity demand when temperatures rise.
Ultimately, “we are vulnerable because we built our lives around air conditioning,” Webber said, living in places where life would be impossible without it. The stress that extreme weather conditions are putting on the grid shows that “climate change is here and we need to deal with it”.
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