As the climate warms, increasing the frequency of extreme weather events such as heat waves, cities including Santiago de Chile, Los Angeles and Melbourne have taken the step of appointing so-called chief heat officers. Their job is to find ways to protect citizens from the dangerous effects of extreme heat.

Eleni Myrivili, who got the ball rolling in Europe when she was appointed to the role in Athens, Greece, says awareness around natural disaster risks is key. In that spirit, two years ago, she and her team began categorizing heat waves in terms of their effect on human health. 

"We now have a way of predicting the types of heat waves that are going to come next week, whether they're particularly dangerous for people or not so dangerous," she said.

Once it's apparent how bad a heat wave is going to be, those most at risk are told how to stay safe.

The initiative, which has since spread to other countries and cities, ties in neatly with a recent UN announcement to invest $3.1 ($2.8) billion to ensure everyone on the planet is covered by early warning systems by 2027.

"The idea behind the mission is that every person who loses their life due to weather, water, climate or related environmental hazards is one too many," said Johan Stander, director of the World Meteorological Organization (WMO) Services Department. 

What are early warning systems and how do they work?

Given the different weather extremes that require early warnings and the endlessly varying sets of personal circumstances to be taken into account, there is no one single fix for getting people out of harm's way.

But Kurt Shickman, director of extreme heat initiatives at the Washington-based climate resilience foundation Arsht-Rock Center, says messaging is key, "because there is a lot people can do with their own behavior to keep themselves safer."

Radio, TV and text messages can be powerful communication channels, according to the International Telecommunications Union (ITU), the UN agency for information and communication technologies. And text messages can even be targeted to specifically reach those in at-risk areas. But with more than 2.7 billion people on the planet still offline, such channels can only go so far. 

"That's a great concern," said Cosmas Luckyson Zavazava, Director of ITU's Telecommunication Development Bureau. "Out of the world's 46 least developed countries, 26 are in Africa. And these are huge countries where people live in remote areas, and it's difficult to reach them as they are lagging behind in terms of connectivity."

He says one solution is to launch satellites, especially low Earth orbit (LEO) ones, which are more affordable and make it possible for populations even in remote areas to be covered by a signal.

ITU is also betting on a multi-hazard approach which makes use of whatever is available. In many isolated places across the world, church bells, loudspeakers and sirens are still used as backup warning systems, for instance.

Back in Athens, the message about coming heat waves is spread via social media, telephone hotlines and an extreme heat app that's now also being used in Milan, Paris and Rotterdam.

"Our app Extrema Global shows you your personalized risk, depending on where you are in the city and your age and your gender and whether you have preexisting conditions," Myrivili said. "It also tells you on the map where to go to take cover, where the cool spots are around you."

Bangladesh built storm-resistant shelters ahead of time

Letting people know where they can take shelter is important. As is building those shelters. One country that has excelled in that field is Bangladesh.

Scarred by the 1970 Bhola cyclone — the deadliest recorded in human history — which killed as many as half a million people, the South Asian country has gone from 42 shelters in the 70s to more than 12,000 today.  

And that has paid off. When Cyclone Amphan hit in 2020, it claimed the lives of 128 people across India, Bangladesh and Sri Lanka. By comparison, almost 200 people died in Germany when major floods ravaged the country one year later. The rains were less heavy, the region much less populated and less low-lying, yet there were more fatalities.

"Bangladesh is streets ahead of any other country in the world in improving its ability to manage the risks of natural disasters," Saleemul Huq, director of the International Center for Climate Change and Development (ICCAD) and one of the world's leading experts on climate adaptation, told DW.

"We can typically warn and move 2 to 3 million people every time there's a cyclone warning and the deaths have come down very significantly."

Storm fatalities in Bangladesh have dropped from six figures to double digits in the space of a few decades.

More data, digitalization and local expertise needed

Early warning systems assess risks using meteorological data. The problem is that this can only be done successfully when weather data is openly shared among all member states, according to Stader.

"Weather systems move across borders. Our infrastructure and data from the ground is extremely important," he said.

In 2021, the WMO made a resolution that the meteorological services in UN countries have to share their weather information. But not every country has its own data — at least, not digitalized. In Tajikistan, for example, a century's worth of weather data only exists on paper. 

"Digitization of historic data is not an easy task," Stader said, but added that doing so could provide more precise weather forecasts or be applied to climate modeling.

What to do with the data when it's there?

In order to help experts improve the overall analysis of meteorological data with a view to predicting weather events, the WMO has opened regional centers that provide acces to training in severe weather forecasting.

But Zavazava says it is also important to offer the general public regular training and drills so they know how to interpret different signals and how to find the nearest escape routes or shelter.

"Once, an alarm was given through a siren and it was very musical. The small kids in the community were dancing, thinking that it's music when in fact it was an alert, but people didn't know and so they didn‘t seek shelter," Zavazava recalled.

"So we have to design alarms in a way that they irritate. The alarm also needs to be followed by a message in the local language explaining the next steps. That will automatically save lots of lives."

Edited by: Tamsin Walker