- 2 days ago
Innovative projects involving bricks made from soil, urban greenery, superblocks and solar power show how climate action is setting new standards – even if conservation measures don’t always win public support.
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00:05From building with wood to recycling concrete, the construction industry is looking for ways
00:12to reduce its massive carbon footprint.
00:17But it's still early days for change in the sector.
00:23One new sustainable approach and much more coming up on Tomorrow Today.
00:33Could this soil be the answer to the construction sector's dirty little secret?
00:38We have to really speed up things and we have to drastically transform the way that we handle
00:44and consume resources on all levels.
00:48Every week a truckload of soil lands in an old aircraft hangar in Berlin.
00:52It looks just like regular dirt, because it is.
00:55But squashed into blocks, it becomes something potentially revolutionary, compared to traditional
01:01clay bricks, making the soil blocks emits 97% less carbon dioxide.
01:06A revolution is needed because in environmental terms, the construction industry is filthy.
01:11The building sector is the world's biggest polluter.
01:14According to the UN, between 2024 and 2025, it accounted for 34% of total global CO2 emissions.
01:22Over the same time period, that's more than the automotive and aviation sectors combined.
01:27One reason is the way traditional building materials are made.
01:31To make them strong enough to use, clay bricks are baked in furnaces
01:34that hit temperatures exceeding 1000 degrees Celsius,
01:37and they have to spend several days in the oven.
01:40Those kilns are typically powered by fossil fuels
01:43and release massive amounts of soot and carbon dioxide into the atmosphere.
01:48It's very cheaply and very fastly built, with no intention of lasting longer than 40 to 50 years, which is
01:55insane.
01:59As soon as they're no longer wanted, buildings are often razed to the ground,
02:03and a lot of that debris just ends up in landfill.
02:09Christian Gaeter, earthbound, hopes his blocks could change this.
02:13The soil for them is taken from excavation waste on a construction site on the outskirts of Berlin.
02:19Germany's Federal Environment Agency reports demolition and construction waste like this
02:23comprises the country's biggest waste stream.
02:26But this earth has a different destiny.
02:29We were very interested in this sort of devalued chain of excavation material
02:33being moved from the construction site and then just deposited in landfill as a waste.
02:39So we thought there was great potential in actually using this resource.
02:42After reaching Christian's site, the soil is first dried and broken up,
02:47then mixed with a tiny bit of water and compressed.
02:53There's two things that really come together here.
02:56One is that the production process doesn't use any other chemical binders,
03:01which on the one hand means that it's very, very low in terms of CO2 emissions.
03:05And on the other hand, it also means that there are no toxic gases
03:08or any toxic substances released in the process
03:11when a building is constructed from the material.
03:14The eco bricks compete with their traditional counterparts
03:17in terms of their ability to bear loads
03:19and can support a building of up to 17 metres tall,
03:22four or five storeys high.
03:24Each brick can withstand roughly 29 metric tonnes of pressure before breaking.
03:29That's roughly the weight of 15 cars.
03:32The blocks can be laid with mortar and plaster also made from earth.
03:36Rooms in houses made from them are cooler and more humid.
03:39I really hope that we can sort of take on
03:42the conventional masonry construction sector
03:45and substitute a significant share
03:47of what nowadays is built with carbon-intensive
03:50and also materials that are not recyclable at the end of the life cycle
03:54with the earth blocks that we are producing
03:56which are 100% made from waste materials,
03:59very low in terms of CO2 emissions during the production
04:02and at the end of the life cycle, most importantly,
04:05we can recycle them to new earth building products
04:08without any loss of value or without having to add any new materials.
04:14This is Siene Janssen, a researcher at the Natural Building Lab
04:18at Berlin's Technical University.
04:20She helped design Germany's first building
04:22to use recycled wood in a load-bearing capacity.
04:26But using reclaimed materials is only part of the picture.
04:29Every part of construction is always needing
04:32and you always extract new materials,
04:34you always invest more energy,
04:36you reinvest resources and you also cause emissions
04:41and that's something I think we have to keep in the back of our heads
04:44that even the most sustainable construction
04:48is still causing all these things
04:50and the actual most sustainable kind of construction
04:55is not constructing at all.
04:56Siene's project will be a minerals museum for her university.
05:00She hopes the use of second-hand wood
05:02will spare property developers to follow suit.
05:06I think what's also good about circular economy
05:09is that it's supporting also maybe the development
05:13of business models that are focusing more on refurbishment
05:16and more on transformation
05:18instead of new construction and demolition.
05:21So this may be also then an opportunity
05:23to drive industries and economies
05:28into a more sustainable direction.
05:33Preventing demolition, repurposing buildings
05:35and using eco-friendly materials
05:36are hallmarks of circular construction.
05:40At scale, the practices could help sustainably house
05:44the 2.5 billion more people
05:46the UN says will live in urban areas by 2050.
05:52But what about air quality in those cities?
05:55There are different ways to improve it
05:58one of them surprisingly simple.
06:04Jia Chen from the Technical University of Munich
06:07and her colleague Li Junwei
06:09are in one of the city's parks.
06:11Over the course of several months
06:13they've been taking measurements here
06:15and elsewhere in Munich
06:17to verify their calculations.
06:19They showed that urban green spaces
06:22can absorb surprisingly large amounts of carbon.
06:28We found that urban vegetation in Munich
06:31offsets about 2% of the annual
06:35human-induced carbon emissions
06:37produced by the city's inhabitants.
06:40However, during some summer hours
06:42natural vegetation can completely compensate
06:45for the emissions produced by human activities
06:48or absorb even more than that.
06:52But not all vegetation is equally effective.
06:56Using this device
06:57the researchers can, for instance,
06:59measure photosynthesis activity in grass.
07:02In other words, how much CO2 it absorbs.
07:05At the same time,
07:07they look at how much of the greenhouse gas
07:09is released back into the atmosphere
07:11through soil respiration.
07:14Their findings show
07:15that over the course of a year
07:17lawns are actually a net source of CO2
07:20contributing more emissions than they remove.
07:24Trees are more effective carbon stores
07:27while shrubs and bushes
07:28can also offset at least part of a city's emissions.
07:34We also developed a model
07:36to determine the flow of CO2.
07:38In other words,
07:39where carbon dioxide is absorbed
07:41and where it's emitted.
07:43You can think of it as a map
07:45showing exactly where in the city
07:47CO2 is being taken up
07:49and where it's being released.
07:55Based on their detailed findings,
07:58Chen and her colleague
07:59recommend more greenery in cities,
08:02especially more trees,
08:04because they also offer other benefits
08:06beyond carbon storage.
08:10We've shown that urban vegetation
08:12can absorb CO2.
08:15But trees can also cool cities down,
08:19help clean the air,
08:21and they have positive psychological effects.
08:24My children are always happier
08:27when they're outside in green spaces.
08:32Her recommendation?
08:34City planners should pay more attention
08:37to urban greenery.
08:38It improves the quality of life for residents
08:42and also helps improve a city's carbon balance.
08:49Barcelona showed it can work.
08:52Paris, Vienna, London,
08:55and Ghent in Belgium followed suit.
08:57Now it's the German city of Nuremberg's turn
09:01to experiment with super blocks
09:03when standard city blocks are grouped into zones
09:06that emphasize car-free public spaces.
09:10A jungle gym going up on a playground in Nuremberg.
09:15Gohan Fede is a member of an initiative
09:17to reshape the Gostenhof neighborhood.
09:20The city supports the project
09:22and in the summer of 2025
09:24introduced street closures
09:26and pedestrian zones.
09:28Since then, the challenge
09:30has been to bring
09:31the newly created public spaces to life.
09:35The goal is to significantly improve
09:37quality of life for everyone in the neighborhood
09:40by keeping out through traffic
09:42and creating little oases
09:44for the people who live here.
09:49A year ago,
09:51a community picnic
09:52in the middle of the street
09:53would have been impossible.
09:56Now,
09:57people meet up here to chat.
10:00Elke has been living here for over 20 years.
10:03She welcomes the changes.
10:08It creates new space
10:10for people who don't have a garden
10:12or a balcony.
10:14You especially notice it
10:16on streets
10:16where many families
10:17with immigrant backgrounds
10:19live in cramped conditions.
10:21And now,
10:21there are suddenly 20 children
10:23out playing in the street.
10:27Superblock projects exist across Europe.
10:30Social scientist Lise Ruhrort
10:33from the German Institute of Urban Affairs
10:35has studied them.
10:38The central idea
10:39behind the Superblock concept
10:41is to restrict vehicle traffic
10:43within a neighborhood,
10:45especially through traffic.
10:46At the same time,
10:48it creates more space
10:49for active mobility,
10:51such as walking and cycling,
10:53while often making them
10:54nicer places to spend time.
10:58Improving the quality
11:00of public spaces,
11:01making it more comfortable
11:03for people to spend time
11:04on their streets.
11:06That's why additional seating
11:07is being installed,
11:09with 59 parking spaces
11:11having been removed
11:12for the project.
11:14Markus Heller
11:15is among those helping out.
11:19People who benefited
11:20from free on-street parking
11:22all the time
11:23now find things
11:24less convenient.
11:25I can understand
11:26why that's frustrating.
11:27Whether or not
11:28it's fair
11:29is a different question.
11:32The original Superblock concept
11:34was born in Barcelona,
11:36but smaller cities
11:37like Nuremberg
11:38can benefit as well.
11:40A successful forerunner
11:41can be found in Belgium.
11:44One particularly interesting
11:46example is the city of Ghent.
11:49It reorganized traffic
11:51in a pretty radical way
11:53by basically dividing
11:54the inner city up
11:55into several different sectors,
11:57then preventing cars
11:59from traveling directly
12:01from one sector to another.
12:06As a result,
12:08through traffic there
12:08fell by 60 percent
12:10while cycling increased
12:12by the same amount.
12:13Public transport use
12:14rose by 12 percent
12:16and the effects
12:17weren't just short-term.
12:20In Ghent,
12:21car ownership declined
12:23over several years
12:24from 1.2 cars per household
12:27to roughly one car per household.
12:29These are effects that emerge
12:31when people rethink their habits
12:33in the medium to long term
12:34and then decide they may not
12:36actually need a car anymore
12:38because they use other means
12:39of transport.
12:43Supporters in Gostenhof
12:44hoped for a similar success story.
12:46They organized an association
12:49and raised over 7,000 euros
12:51through crowdfunding.
12:52A flood of volunteers followed.
12:56An incredible number of people
12:58suddenly wanted to get involved
13:00because they realized
13:02they could create something tangible
13:03with their own efforts.
13:05Something that wouldn't just disappear
13:08into a filing cabinet somewhere
13:09but something solid and real
13:11for themselves and their neighbors.
13:13That motivated a lot of people
13:15to join.
13:18Jean-Francois Drojac also lives
13:20in Gostenhof.
13:21He believes the concept
13:23hasn't really been thought through.
13:26A superblock is basically
13:30the same thing as a balcony.
13:32The idea is that people
13:33spend time outdoors.
13:35But how often are people
13:37actually out on their balconies?
13:38Maybe six months a year.
13:40After that it grows too cold.
13:42So for half the year
13:44the superblock will probably
13:46just empty out.
13:49He wants representation
13:51for every interest group
13:53in the neighborhood.
13:56We need to look at what
13:58different social groups
13:59make up society here
14:01and perhaps set up a round table.
14:03One where families,
14:06seniors, singles,
14:07and people with or without
14:09an immigrant background
14:10are all represented.
14:12We should first ask
14:14how the idea
14:14is being received.
14:16What does each group
14:17actually need
14:18in order to accept
14:19the superblock?
14:22Whether a superblock
14:23succeeds or fails
14:25depends largely
14:26on public acceptance.
14:28So who should take
14:29the initiative?
14:30Residents
14:30or local authorities?
14:32Experts say
14:33there's no
14:33one-size-fits-all solution.
14:37On the one hand
14:38it strengthens legitimacy
14:40when residents themselves
14:42demand these kinds
14:43of changes.
14:45On the other
14:46it can mean
14:47that neighborhoods
14:47that have lots of
14:49politically articulate
14:50and active residents
14:51benefit most
14:53because they make demands.
14:55At the same time
14:57areas that might be
14:59in greater need
14:59of improvements
15:00in quality of life
15:01may not be able
15:03to make a superblock happen.
15:09Daniel Ulrich
15:10heads up Nuremberg's
15:11Urban Development Department.
15:13He wants to see
15:14fewer cars
15:15and more buses,
15:16bikes and pedestrians.
15:17To him,
15:18the superblock
15:19is a forward-thinking
15:20experiment.
15:22If we want
15:23our cities
15:23to remain liveable
15:24and to ensure
15:25a high quality of life
15:26even 50 years
15:27down the road
15:28we'll have to change
15:29the physical structure
15:30of those cities.
15:31We still have
15:33too much asphalt
15:33and concrete
15:34and too much parking.
15:37Projects like this
15:38create room
15:39for playing,
15:39outdoor dining,
15:40trees
15:41and for all the cultural
15:42and social activities
15:44people need.
15:46In September 2026,
15:48the decision will be taken
15:50on whether the temporary
15:51changes will be made
15:52permanent.
15:53Its proponents
15:54will do all they can
15:55to ensure
15:56this new public space
15:58will in the future
15:59remain filled with life
16:01rather than cars.
16:05And how are landscapes
16:06changing outside cities?
16:08Germany's countryside
16:09is no longer devoted
16:11just to farms.
16:13Renewable energy
16:14is now harvested there as well
16:16and that can be controversial.
16:19around 60 kilometers
16:21east of Berlin
16:22you'll find the
16:23Merkische Schweiz
16:24an idyllic nature park
16:25that's a popular
16:26recreational destination
16:27for the city's residents.
16:29The question is
16:31for how much longer?
16:32Renewable energy developers
16:34are moving aggressively
16:35into the region.
16:37If investor plans move forward
16:39large solar farms
16:41will be built along
16:42the park's edges.
16:43Opposition has been growing
16:45in the nearby town
16:46of Muncheberg
16:47where an initiative
16:48has stepped up
16:49its campaign
16:50against the project.
16:53We need the energy transition
16:55and we need to
16:55protect the climate
16:56but we shouldn't be
16:57doing it everywhere
16:58and regardless of the cost.
17:00Some gems
17:01like nature parks
17:03need to be preserved
17:04kept free
17:05of large technical
17:06installations
17:07in the landscape.
17:09Though understanding
17:10the concerns
17:11the local chapter
17:12of a nature non-profit
17:14warns
17:14that pitting climate
17:15protection against
17:16nature conservation
17:17is a bad idea.
17:20Jan Sommer
17:21is also active
17:23in the initiative.
17:24His farm
17:25borders one of the sites
17:27being considered
17:28for a solar park.
17:32He's harvesting kale today.
17:34Together with his partner
17:36Sommer grows produce
17:37for the Berlin market.
17:39The farm was their dream
17:41and one they had long pursued.
17:44The couple moved
17:45to Muncheberg
17:4617 years ago
17:48to be as close
17:48as possible
17:49to nature.
17:50They use horses
17:51instead of tractors.
17:53That keeps the soil
17:54from compacting
17:55allowing it to retain
17:57more water.
17:59Organic farming
18:00on 70 hectares.
18:02Sustainable practices
18:04that work.
18:05But plans for solar parks
18:07could now change things.
18:14Our landlords
18:16have been approached
18:17and asked
18:17whether they were interested
18:19in rededicating
18:20the land we lease
18:21to photovoltaic use.
18:24When investors
18:25come and say
18:26I've got a great idea.
18:28I'm taking your field.
18:29And then they go
18:31to your landlord
18:31of many years
18:32and offer him
18:33so much money
18:34that he'd throw in
18:35his grandmother for free.
18:36That's when I'd had enough.
18:39It makes it hard
18:41for me as a citizen
18:42to look at those
18:43vested interests
18:44and say
18:44yeah, you have a great idea.
18:47No, I don't think
18:48it's a great idea.
18:51The farmer fears
18:52for his livelihood.
18:54We tried to speak
18:55with the investors
18:56about his accusations
18:58but received no response.
19:00The utility company
19:02initially agreed
19:03to an interview
19:04but later told us
19:05it had withdrawn
19:06from the project.
19:08For Jan Zoma,
19:10the playing field
19:10is anything but level.
19:12According to him,
19:14the investors
19:15offered his landlord
19:16twenty to thirty times
19:17more than he could
19:18ever afford
19:19as a farmer.
19:20From his point of view,
19:22the future
19:23of the nature park
19:24itself is at stake.
19:27When farmland
19:29is repurposed
19:30from food production
19:31to electricity generation,
19:32farmers stop being part
19:34of their partners.
19:34Young people
19:35will no longer
19:36have the opportunity
19:37to cultivate this land
19:38in a meaningful way.
19:40That doesn't bring us
19:41together.
19:41It'll drive us apart.
19:45Hendrik Wehndorf
19:46also understands
19:48how profoundly
19:49Germany's energy transition
19:50is changing
19:51rural areas.
19:52He runs a farm
19:53in a neighboring village
19:54and represents
19:55a local farmers association.
20:00It creates additional pressure
20:02on farm businesses
20:04because landowners
20:05now have alternatives.
20:08the energy transition
20:10has made those
20:11alternatives
20:11very lucrative.
20:14They can lease land
20:16not to farmers
20:17but to energy investors.
20:21Economist Ralf Michael Markwart
20:23says the issue
20:24goes beyond
20:25just changes
20:26to the landscape.
20:27It's also about
20:28the energy transition
20:29creating winners
20:30and losers.
20:33For example,
20:35if someone leases land
20:36for a wind turbine
20:37they can earn
20:38around 50,000
20:39to 70,000 euros
20:41per turbine
20:42each year
20:43simply by allowing
20:44the turbine
20:45to stand there.
20:46That's an excellent
20:48source of income.
20:49These landowners
20:51are beneficiaries
20:52of the energy transition.
20:53But someone also
20:54loses out,
20:55the farmer
20:56who doesn't own land
20:58and has to lease it.
21:00Jan Sommer hopes
21:02his landlord
21:03will reject
21:03the investor's offer
21:05and allow him
21:06to stay on the farm.
21:07And he'll continue
21:08fighting to leave
21:09the nature park
21:10as it is.
21:12Why, he asks,
21:13should solar arrays
21:14be built
21:15in a protected area?
21:17The beauty
21:18of solar power
21:19is that the panels
21:20don't care
21:20where they are.
21:21They just need
21:22to face the sun.
21:24That means
21:24renewable electricity
21:25can be generated
21:27on sealed surfaces,
21:28rooftops,
21:29and parking lots.
21:30There they don't
21:31cause problems.
21:32On the contrary.
21:35Officials in Münchenberg
21:37say they're carefully
21:38reviewing all the arguments
21:39and that a decision
21:41has yet to be taken.
21:43Conservationist Björn Elner
21:45has seen similar
21:46disputes elsewhere
21:47and how they end.
21:51In Brandenburg
21:53there's a law
21:54stating that
21:55municipalities
21:55have to receive
21:57financial compensation
21:58when solar farms
21:59or wind turbines
22:00are built.
22:02And since
22:03public budgets
22:04are tight
22:04almost everywhere,
22:05there's a strong
22:06incentive for
22:07local authorities
22:08to make land
22:09available for
22:10these kinds of projects.
22:15It's a tough
22:16balancing act,
22:17not only for
22:18local authorities
22:19but also for farmers,
22:21says Henrik Weindorf.
22:22Many of them
22:23would also like
22:24to go into
22:24electricity production
22:26with their own
22:26solar projects.
22:29As people involved
22:31in agriculture,
22:32we're in a difficult
22:33position.
22:33On the one hand,
22:35producing food
22:36is our primary
22:37responsibility,
22:38and only farms
22:39that are economically
22:40stable can fulfill
22:41that responsibility.
22:45And that also means
22:47agricultural businesses
22:48need to consider
22:50how they can
22:51use the land
22:51they own.
22:52I'm specifically
22:53talking about
22:54land owned by farmers
22:55to strengthen
22:56their economic
22:57stability.
22:58And that can include
23:00investing in
23:01renewable energy.
23:05For now,
23:06Jan Sommer
23:07has to just
23:08wait and see
23:09what the authorities
23:10decide.
23:11Land ownership
23:12plays a crucial role
23:13in the issue,
23:14both for him
23:15and for
23:16Germany's energy
23:17transition.
23:22Speaking of renewable
23:24energy,
23:24here's a great question
23:26from our viewer
23:27Bernard in Ghana.
23:32How do solar panels work?
23:36Solar panels,
23:38also called
23:38solar modules,
23:40are made up of a number
23:41of solar cells
23:42linked together.
23:43About 95 percent
23:45of all solar cells
23:46are currently made
23:47from silicon
23:47obtained from quartz sand.
23:50It's melted
23:51and cleaned
23:51in a complex process.
23:53The resulting silicon
23:54is cut into thin slices
23:56called wafers.
23:58To make the cell
23:59electrically conductive,
24:00the silicon is
24:01intentionally contaminated
24:03or doped.
24:04Some wafers
24:05with boron,
24:06others
24:07with phosphorus.
24:10When the wafers
24:11doped with boron
24:12and phosphorus
24:13are placed together,
24:14excess electrons
24:16migrate
24:16from the phosphorus
24:17silicon layer
24:18into the boron
24:19silicon layer.
24:20This leads
24:21to a surplus
24:22of electrons
24:23at the bottom
24:23and a shortage of them
24:24at the top.
24:25Similar to a battery,
24:27solar cells have
24:28positive and negative
24:29poles.
24:30When sunlight
24:32strikes the cell,
24:33electrons are released
24:34in the silicon
24:35boron layer.
24:36Since they're
24:37negatively charged,
24:38they're drawn
24:38to the positive pole.
24:40Solar cells
24:41also have metallic
24:42conductors
24:43at their top
24:43and bottom.
24:44The free electrons
24:46travel along these
24:47tracks, generating
24:48an electrical current
24:49as long as the sun
24:50is shining.
24:56When more light
24:57strikes the surface,
24:58more power is generated.
25:00To increase yield,
25:02solar modules
25:02are usually connected
25:03in series
25:04and linked up
25:05to form larger systems.
25:08But even small
25:09modules can generate
25:10enough electricity
25:11for everyday needs.
25:13More than 11%
25:14of all renewable energy
25:16already comes from
25:17solar energy,
25:18an increasing trend.
25:20It's a form of energy
25:21with almost infinite potential.
25:27What are stars made of?
25:30How many colours
25:31can butterflies see?
25:33Could robots
25:34have babies one day?
25:36Do you have a science question?
25:38Then send it to us
25:40as a video, text
25:41or voice message.
25:43If we answer it
25:44in the show,
25:44then we'll send you
25:45a little gift
25:46as a thank you.
25:47So, just ask.
25:52That's all we have time for,
25:54but we hope to see you again soon
25:56on Tomorrow Today.
25:57Bye for now.
26:05Bye for now.
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