With climate change it will probably get even warmer in the city – but the heat has long since arrived. In a study for the “Green City of the Future” project in summer 2020, scientists determined whether, how and where people in Munich are already experiencing heat. And it shows: In certain places and in certain neighborhoods, people have long been suffering from heat stress – and some residents are more affected than others.
To do this, the researchers didn’t just go through the city with thermometers: They were not only interested in the objective temperature, but also in the perceived temperature. Therefore, they interviewed residents from across the city; 731 households took part. And the streets feel particularly hot for them, followed by the workplace. More than two thirds of them stated that they felt “somewhat” or “very much” exposed to heat in the street; In contrast, green spaces feel cooler, where it was less than ten percent. On the other hand, the majority of those questioned were satisfied with the temperatures in their own homes – at least as long as it was not more than 30 degrees Celsius outside. During heat waves, 53 percent of those surveyed also complained about heat at home.
The people of Munich have very different individual experiences. Heat does not affect everyone equally. For example, in addition to their surveys, they measured the temperatures in the bedrooms in 342 households. They determined: In some of them it was up to 37.5 degrees Celsius. In others, however, it was never more than 20 degrees. A maximum of 24 degrees Celsius is recommended.
In general, it is warmer in the city center than on the outskirts. “There is a connection between heat and heat perception as well as the density of the city,” says Julia Mittermüller from the Institute for Sociology at the Ludwig Maximilians University in Munich. The more buildings, the more crowds and the more traffic, the hotter the city would appear to people. “Conversely, the more green there is in the area, the less people complain about heat.” It is enough to see trees and plants to reduce heat stress.
People who live on upper floors are also particularly affected by heat. It doesn’t have to be the top floor, says Mittermüller: The floor is more important. “The height is more important than the roof.”
But the data suggests that other factors also play a role. For example, respondents complained less about high temperatures the larger their apartment was and the more square meters each resident had to himself. Conversely, the sensation of heat was stronger in cramped and crowded conditions. Residents of multi-family houses suffered more often from heat than those in single-family houses. Tenants complained more often of heat than owners, and those who lived alone more often than people in community. People with previous illnesses suffered from heat more often than healthy people, and younger people complained more often than older people – which, according to the study, is based on the fact that the older people surveyed tended to live in cooler apartments.
The psyche also obviously plays a role: Those who were dissatisfied with their own financial situation complained more often of heat than people without money worries – without there being any significant differences in the objectively measured temperatures. And those who felt unsafe in their living environment complained more often than Munich residents, who felt they lived in a safe area.
According to the study, it is also important whether people feel exposed to the heat or not. Those who feel that they can control the temperature in their home complained less often of heat than others. The differences could also be measured objectively. “In the southern part of the station, for example, many people cannot open the windows at night because it is too loud and too warm,” says Mittermüller. “Nightly ventilation would be the most effective way of lowering the temperature.”