speaking, how can this passionate hatred of a people be explained? a gold hon. go. a history of anti semitism is a history of stigmatization and exclusion of religious and political power struggles. it's a history of slender, of hatred and violence. even 77 years after the holocaust hatred towards jews is still pervasive. oh, a history that you semitism this week on d. w. ah, welcome to a new edition of tomorrow to day coming up. could vintage technology help reduce airplane emissions? can you make environmentally friendly concrete, out of carbon dioxide and reports it finds out and we show how

harnessing the wind could help cities cope with climate change tomorrow to day. but d w. sun show heat waves in the northern hemisphere, reco temperatures around the globe from dubai to delhi, to paris. 2015 was the hottest. yes. with reco it's began. according to the world material, logical organization, it could soon get even more sweltering. but before we take a look at ways to keep cities livable, despite rising temperatures, we hear what our fee will have to say. i do you live in a city or a region where it gets really hot? how do you cope what to local authorities to you to tackle the problem?

that's what we asked you on social media. ah, inside rights in el salvador, nothing is being done. everyone just buys their own air conditioner. mm. audrianna in pakistan, columbia says the city is always been hot, so you need to keep hydrated with sunscreen. use clothing and sandals. unfortunately not much has being done to protect the environment. in another place from the south american country, mary lou's right. i live in katerina columbia, it gets unbearably hot here and there are no initiatives to compensate for the high temperatures. i keep lance inside and out use them all curtains and a fan. ego from answer from indonesia is planning on planting, shade trees in the yard, and suggests it would help if everyone planted a tree. others sebastian is thinking along similar lines and is going to install the pond and the god from mexico. chavez, gregorio,

7 or 8 rides i live in a city in northern mexico, with temperatures can reach 40 degrees and they rising every year. an additional problem is that water is very scarce. neither previous governments nor the current one have launched any reforestation programs. as far as i know, instead of planting trees, they built more streets and shopping malls, reducing public space and making the city bigger. thanks for your comments. in our 1st, we thought we had to hamburg to find out and win, serve as a natural inclination to keep cities cool. a gust of wind can quickly turn into a bad hair day. urban residents usually only think about wind when it bothers them . but a fresh breeze can also help us feel good in an urban setting. city planners and scientists across germany have been taking a closer look at the complicated place between wind and architecture. because wind

is an important parameter for an urban climate. bethesda, sooner thus didn't, a nice thing is that everyone can benefit from the wind, but wind, you can also be difficult in the city and very a lot, but you have to make sure you don't design. i should be in a way that know when a can get through it all into like us, that'd be fine in winter or during autumn storms. but in the summer, you'd have a buildup of heat with no air circulation from the surrounding area. minimum lansing also meteorologist akio hansen is collecting data and hamburg port area of, of his focus is on wind. comfort of the idea is that an area needs to be ventilated, but not have wind corridors which make life unpleasant for residence. when this district was planned, wind comfort clearly didn't play a key role. lesson in length, we're measuring along this street with the port area because it has interesting

wind conditions at all. i know i am fight, there's an entree path for the wind, as well as a complex building structure which completely influences the wind complaint binds on. duffy see that on the street corner, the wind gusts are up to 3 times as strong as the average wind speed here. i model navy the middle of of it. on a typical autumn day, wind gusts here can quickly reached up to an uncomfortable 120 kilometers per hour . the data ratings are used to create a computer animation. it shows the high wind speeds and extreme turbulence that develop small changes could help improve the situation. it would, i would try to plant a significant amount of greenery along the key wall. adding trees would help to slow down the wind generally in so name i brooklyn's, cuz you can see that all over the world's got herb and greenery has many advantages

. it doesn't only influence the wind, but also helps with other phenomena like particulate matter of, you know, minute be fine. but of course it would make more sense to factor in the wind when planning the construction of buildings. that's what kristof clunker from the carlswell institute of technology is working on. he's aiming for optimal ventilation of entire cities. unobstructed corridors are important, so air from the surrounding area can flow into the city at night. im stuck, if you'd say bottom in the urban area itself, you have warm air was lower density which rises at the same time. a cooler air from the surrounding area is sucked in from the sides of it all. that's very important. so we can all sleep well at night when it's too hot, we all sleep badly and laughing on reflection. in general, the la and you're a city is the hotter it gets densely built up areas slow down the wind and store

heat. at night, the temperature difference between the city and the surrounding area can be as much as 10 degrees celsius. new housing developments can put the necessary fresh air corridors in jeopardy. we turned to another german city, mannheim. almost $1600.00 new residential units are to be built there on the site of a former military barracks. but how well will the quarters behind them be ventilated? following construction. to find out, christoph clunker simulates the night time flow of cold air with a model of the city decay croft. emily simulate cold air using a heavy gas mixture. cold air has a higher density than hot air gods while much. so we take normal air and mix it with heavy guess to disgust. then we add a miss to it to make it visible. lennon flow slowly into our models, lung from yard. his research shows that demolishing the old military barracks has

actually improved the inflow of cold air into the city. the new buildings by contrast won't block the cold air flow. that's an important factor for efficient ventilation. he marvin the kite goofed off. i'm, whenever a cold air meets an obstacle hoof such as a building and you don't, it can either floor around the building would or hoards, deflected upwards and then flows over the building voided. if it's deflected upward building, there is a possibility or risk of the colder will mix with the warmer air above it and then the colder will be diluted or the flow stopped fine for doing it so far. so it's all buildings on the edge of a city should certainly be avoided, who are good boy on that hunt, that often fights with allied global warming and increased urban density pose major challenges for the city. planning of the future scientists are currently receiving funding from germany's research ministry to develop a computer model for wind forecasts designed for use with new building projects. it

features small scale climate models to identify problems early on, so that city planners and architects can factor in wind and ventilation during the design phase. with climate change advancing, we can't afford to repeat the mistakes of the past and was rejection to alpha. we have to make sure when we build that we take the future into consideration and ensure the buildings can withstand the changed climatic conditions about height. not too dense, not too hot, not to drafty. it's clear that analyzing when conditions in the planning phase is essential to making cities livable in the future. how to best adjust to climate change and rising temperature, the unit, the u. n. z environmental program for instance, recommends plants and trees to provide shade and low in air temperature for housing . but storms and heavy rain are another result of climate change. so houses and

roofs in particular need to be secured against extreme weather and in regions that are vulnerable to cutting, it makes sense to build more houses on stilts. another recommendation of the un environmental program. but maybe it makes sense to get to the root of the problem. concrete is the most commonly used building material in the world. it's been used for more than 2000 years. it's basic components of cement, water, and sand. but the drawback is cement production is a major source of global c o 2 emissions 3 d printing is one solution. 3 d printed buildings made with real concrete are now a reality. but they're all conflicting opinions on whether or not the process really does cut carbon emissions. either way,

research is eager to find ways to reduce the carbon footprint of the cement industry. d, w reporter off my collage. he investigates the new technology being pioneered by canadians data. hey, ever heard of this? you can build, haul through with god. ah, no joke. you can make concrete auto, carbon dioxide. well, that's what i heard from a start up in canada. wait, did i hear that her? hey madison, can your company really make concrete out of thin air? we can't actually me concrete out of out of been here. but we do is we have a ceo to you, embedded or enhanced supplementary seminar history materials, the very long worry. but essentially it's an additive that can replace a portion of cement in a concrete mix. okay? not really concrete, auto see or tool, but something that replaces

a part of the cement confused. let's break it down. concrete is basically made out of the ingredients, cement, sand, and water. and it seems to me that it is everywhere. right madison colgate right now is the 2nd house you substance on earth other than water. currently, the rate of growth in the built environment is about equivalent to building one new york city every month while building houses and infrastructure. the great thing with a little problem, this is the bad guy. the production of cement, emits enormous amount of t o 28 percent of all greenhouse gases are caused by the construction industry. that's huge. madison said her company has a solution. a substitute made out of surprising ingredients,

industrial waste like ashes and c o 2. when you have time to process technology and that kind of comes in the form of a very large reactor, especially how it works is we put our solar heat into the vessel. and then we pressurized that with c o 2. and we rotate the vessel for a number of hours. okay, let's go industrial risk like asha. and you are to ah, what's happening in the chemical process? the c o 2 molecule minute alive with the industrial arches. it is as if the greenhouse gas force eliza a completely different material comes out and it can replace up to 40 percent of the semen. the production does not emit greenhouse gas,

it absorbs it. oh, in other words, the climate damage in greenhouse gas is dropped in the concrete madison. you want to build the future with the waste of today. we project that by 2030 will be able to achieve 600, make tons of carbon reduction. good luck. using cement substitutes can't make the construction industry completely green, but it can at least make it a bit greener. the cement industry is responsible for even more carbon emissions than flying. but that doesn't let the ation industry of the hook, international air traffic increases every year. even during the global pandemic, over $20000000.00 flights took off worldwide.

the more flights there are, the more carbon emissions are produced. one way of making aviation more sustainable is switching to alternative fuels. reduce the amount of fuel used in the 1st place is another option. and that involves the thinking engines. boosting airplanes, fuel efficiency is taking far too long. minor technical improvements have led to a mere one half per cent drop in fuel consumption. up until the pan demick annual passenger numbers were rising by 5 percent. growth has led to 10 times more emissions than modern aviation technology can conserve. professor dita schultz at the hamburg university of applied sciences thinks that the industry does far too little to protect the climate. elizabeth taking a v gigs plant. we must counter this with technology for it's not as if there weren't enough ideas or projects. the question was simply whether everything is

targeted enough and whether there's enough technological openness, others can new technology, offline, up moved. it may be that we even need to look to the past. i had cocoa in salzburg airport. hanger 7 is the last authorized dc, 6 passenger plane and inter continental airplane. we want to know which advantages the asian technology of the 1940s had. and if there's anything we can learn from it this douglas dc 6 was yugoslav. dictator tito is a government plane until 1980 to day a soft drink producer uses it for air shows and the formula one team uses it for travel. this cynthia, here we are inside our dc 6, which is furnished quite luxuriously with somewhat heavier seats and heavier interior furnishings. to enable more comfortable travel, which we've limited to 35 passengers and crew that uh,

this plane used to carry up to 108 people and it's furnished like today's economy class. so me growth. the d. c 6 has a range of 8000 kilometers and a crew speed of 500 kilometers per hour. for its time, it was an outstanding technological achievement. the dates of x with careful the dc 6 has fallen by 2 pilots and an on board engineer who sits in the middle and who specializes in operating the flight instruments and who also fine turns the unlocked here. the good list here we have the mix regulator law. we can simply set it to fly very efficiently, busy if by some latent to day fuel consumption in aviation is passenger oriented. modern airplanes use on average $3.00 leaders of kerosene per passenger for 100 kilometers. the dc 6 was much more efficient than planes to day because piston engines and propellers use the fuels energy much more effectively. did i

disney movies? i shall see if it's in for that. most people are amazed at how efficient flying was back then you thought porpoise about $1.00 leaders per person for 100 kilometer. he said he hit the frontier. that's about half of today's fuel use less heat. oh, and you can see how much was done in the 1st 30 years of flying. and how little was done in the following 80 or 90 years in the, in the, at least in terms of fuel efficiency. 6 nights examples. read aircraft in western germany has rediscovered the advantages of the piston engine for airplanes. instead of using jet engines, read aircraft uses ultralight turbo diesel engines. they are twice as fuel efficient as jet engines. and they have an important advantage over turbo jets, which are only efficient and high altitudes. diesels turbo charger also makes it highly efficient during take off and landing. at the moment $25.00 diesel

engines are built here each year. even though each engine is built by hand, they are 7 times as efficient as comparable turbo jets this diesel technologies full potential has yet to be realised. the red motor shows what it can do with just $95.00 leaders of aviation fuel per hour. this diesel engine is 60 per cent more efficient than a turbo jet. within a season, we see the diesel engine as future proof and because we can always increase the fuel efficiency before we can immediately deploy sustainable fuels. and in order to do justice to the expensive fuel, we can switch to hydrogen combustion. if we can hybridize, we have all these options. diesel is to motion. propellers can also be improved as this bavarian company shows it's multi blaine propellers have earned it

a global reputation. they're coming up on, we go from loud vibrating to blade propellers to 4 to 5 blade ones that are quiet the lice. if we don't use energy to make noise anymore, but to boost thrust full of and we're working on 79 and 11 blade concepts off to move the whole idea forward to hypo, to putting a discount to clinton. high tech propellers are a serious competitor to jet engines. a victim of our estimates and simulations sure will be able to deploy propeller airplanes sufficiently up to a speed of about 800 kilometers an hour. given that we're developing this technology, this propeller has potential in terms of the future propulsion systems. pip systemic auto aviation and los angeles shows just how much airplanes using diesel engines and propellers can be improved. company founder william auto uses red diesel engines from western germany and an empty propeller from bavaria. he also

optimize as his plains aerodynamics autos. celera $500.00 l permits inter continental flights at 740 kilometers per hour. and on top of that, it seems 80 percent more fuel than the competition the element to the roof, but at the legacy and hum the elements that we've seen with the celera what can absolutely be transferred to large passenger planes. here's an example of such an airplane with 180 passengers. what's crucial is that this large plane now has a propeller engine, with a few other technical refinements nestled. he's in that really it was, of course it's somewhat slower while a nuisance was, but in particular it flies deborah doesn't have contracts and therefore avoids global warming to a very great extent available in 0 stack. and last, 3 small companies are showing the mighty aviation industry how to build fuel efficient airplanes with modified but familiar technology,

a giant leap forward for climate protection. have you ever wondered why plains need to be de iced in winter? well, frozen contaminants can add weight and interfere with the aerodynamic properties of the plane. take off and landing when the plane passes through clouds are especially critical. 10 kilometers and more above sea level, the outside temperature is a freezing minus 50 degrees celsius. and that means there's no more moisture in the atmosphere that can turn to ice on the plane surface. and that leads to the question asked by avila hans d to dawson from tanzanian. oh, why is it colder at high altitudes, even though we're closer to the sun? let's take a closer look at the earth's atmosphere. it's made up of 5 layers. the lowest one

is the troposphere. it's up to 7 kilometers high at the poles and 17, near the equator. all it's temperature drops by around 6 degrees celsius per kilometer. and that's due to the composition of the air around 99 per cent of the atmospheres. water vapor is found in the truck was sphere, the water vapor, aplus, carbon dioxide, methane and other greenhouse gases, keep temperatures constant on earth. without them we'd be looking at an average of 18 degrees celsius below 0. the further way we get from sea level, the thinner the air gets, so that means it 1st gets colder. but the mountaineers need to bundle up to survive at high altitudes. the top of mount everest gets to minus 60 degrees celsius. so far, at least the higher you are, the colder it guess. now,

lips head to the stratosphere, 50 kilometers above earth. here things start to warm up again. that's because the ozone layer absorbs the sun's uv rays and turns them into heat. so temperatures can climb back up to 0. the stratosphere is also where weather balloons take their measurements. and some volcanic eruptions are so powerful that their gas in debris reaches far as the stratosphere next comes the mezzo sphere. there are hardly any ozone molecules here. so the temperature drops again at the top edge of them as a sphere. you can get to minus 120 degrees. the cold is spot in the earth's atmosphere. but the arrows still dense enough to protect the earth. the friction of the gas molecules burns up all but the biggest mead yours and most

commissions spacecraft and satellite, also incinerator on re entry. and it's like turning in the thermos sphere and exit sphere temperatures sore all the way up to 1500 degrees celsius. so the higher the colder isn't a universal rule. mm. what matters is the different physical conditions at the point in the atmosphere and the chemical composition of the gases there. if i was let is read why i gave you, if you have a science question, you'd like us to answer, then send it in. if your question is chosen for the show, you also receive a small surprise from us as a thank you. come on just dos. and

if you're interested in more stories on science and tag, you can find us online at d, w dot com slash science. and on twitter, that's it for this week. so thanks for watching and see you next week for another edition of tomorrow to day. until then, goodbye with ah, ah, ah ah

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