Saudi Arabia says more than 1,300 died during hajj pilgrimage due to heat

Well, for more analysis on what can be done to make events like that safer and how we're changing our attitude towards extreme temperatures, we can cross the Las Vegas and speak to Stefan Lehmann, who's a professor at the School of Architecture and director of the Urban Futures Lab. Thank you so much for speaking to us, Professor Lehmann. I mean, clearly the whole world is heating up. What sort of steps need to be taken from an infrastructure point of view to make sure a tragedy like the one at the Hajj doesn't happen again? Hi Tom, this is great to talk to you and it's such an important topic. Thank you for raising it. We can do a series of things. In fact, we need to apply multiple solutions here. And to be honest, most cities, not only Mecca, are inadequately prepared for the global rise of temperature. For instance, we need to plant trees re greening the cities. Urban vegetation is very important and it's the most cost effective way to cool down the microclimate and to avoid the urban heat island like we have seen it here in Mecca. There was poor tragic loss of life of those poor pilgrims in Mecca in 50°C. We need continuous shading. The most important in the desert city like Mecca or here in Las Vegas where we have 42° at the moment at noon is to have continuous shade. So either you have canopies or you have continuous trees planting that provide a continuous shade. So walking is more safe, but also we must avoid what's called the urban heat island effect. And so we need to have different materials that do not absorb and and trap and store the sun radiation and become a baking oven. Those poor people collapsing, of course, because they are maybe not dressed appropriately, they underestimate the heat and they don't have enough water. So planting trees would help. Continuous shading would help and cool roofs, facades, white colored reflective surfaces, avoid buildings and parking lots that become urban heat islands because black colored or the worst is black asphalt. So we need to use what's called the albedo effect that bounces back the solar radiation and avoid concrete and avoid everything that counteracts pedestrian comfort. I'm not surprised so many people are collapsing. That's quite expectant because the mortality rate in a heat wave goes up not just double, but four to five times of what it is before and after the heat wave. And so these are heat related mortalities that could have been avoided, I must say. And the urban heat island is a problem everywhere here. Las Vegas has already increased. It's the fastest warming city, but also Phoenix and Albuquerque and even to some extent in Paris. You, you experience it in the summer, the urban heat island. Yeah, it's definitely getting hotter here as well. I mean, the desert is of course, going to be the focus of some pretty major architectural projects, especially in Saudi Arabia. I mean, that does suggest, doesn't it, that we are as a as a species, getting better at adapting to extreme heat conditions and technology, of course, a very big part of that, yes, air condition, of course, since the 1950s made it more comfortable to live in desert cities. And in fact, desert cities, you're right, are some of the fastest growing cities in the world. Not just Cairo, Karachi, Tehran, but also Vegas, Phoenix, Lima. These are all fast growing cities. And the heat is a silent, invisible killer. But it's also the air pollution that comes with the heat. There is a strong link between the heat wave and less air quality. It's a serious health concern. You will know that when you are in a desert city then you're having a heat wave. People get asthma problems, they have breezing problems because the drop of air quality is significant and the air pollution like pollutants, ultrafine particles are stagnating in the air like we have at the moment here. It's a heat Dome. It's a high pressure system that traps and push the air down. And so the air doesn't clean itself anymore. There's no rain to to clean the air and the air quality is getting worse and worse. And so breezing is just becoming a problem and people get heat strokes very easy as heat all the time. We had tragic loss of life here already this year in the desert here in the Mojave Desert, where people completely underestimate the danger. And they think they can go hiking and and they may be dressed in black and they have a tiny water bottle and they go hiking and they realize they cannot make it back. And then they try to find some shade. And this is where they dehydrate and end up often getting a heat stroke, unfortunately. So that's very common in desert cities, but also more and more in other places. You know, at the moment we see wildfires in Portugal, in California. We have heat waves in India. We have disappear disappearing tourists in Greece, we have collapsing tourists on the Las Vegas Strip and we have, of course the Muslim pilgrims in Mecca at this very hot time in summer in 50° and many of them are perishing unfortunately. It's tragic. It could have been avoided with multiple solution strategy that I mentioned. Planting trees is the most cost effective, Sure. I mean, it can be done in a sustainable as a sustainable way as well, can't it? Because you think about that infinite source of heat coming from the sun, you'd have thought that could generate considerable power, which in turn could run AC units and and keep people cool, certainly indoors. Absolutely. Tom, you're spot on here. And also we need ideas of new products, new building products. It's a time for innovation, entrepreneurship and companies creating new products that are more heat resilient. We don't need ideologies. This is really about entrepreneurs creating better products for the construction building market to face to future proof. Our cities facing a hotter future. We're going to have longer, more intense, more prolonged heat waves. It becomes very common in many cities. We see it in Los Angeles too, and in many, many cities here in the Southwest where we have at the moment 100 million people in 30 cities. The heat watch and same happened last year and the year before. And it seems like it has become the new normal. At the moment we have 42° here in Las Vegas at 12:00 and it's going to go up to probably 4344. Last year we had even 47° in June. It was a new record for Vegas. And it's just every year we see new heat records beaten. It's pretty frightening. Some people joking or are cynical, saying that the Southwest in the US cannot be inhabited in future, in the end of the century 2100 it might just simply too many days about 40°, making it harder and harder. Of course, we can use air conditioning, but air conditioning is creating also a peak demand of energy. And if the energy is not provided from the clean solar power, we have a problem again burning coal, oil, which doesn't help. Again, it's a vicious cycle we have engaged in. We are engaged in this circularity, this loop that could spin off and create worse conditions if we're not counteracting. So, yeah, So that's a serious problem. And thank you so much, Tom, for raising it. And the guy is just an example where we can see the terrible consequences if we build cities in the wrong way. And we have urban heat island, and thousands of people come there to do their pilgrimage. And it's just not ready, not, not made for this heat. Yeah, That's absolutely tragic. We're going to have to leave it. I'm so sorry to cut you short, but we're out of time, I'm told. But thank you very much, Professor Stefan Lehmann. Thank you for speaking for us having me. Thank you, Tom.