The Green Paths to Future initiative in Dubai spans about 10 miles and stands as a groundbreaking eco-project to redefine Dubai’s urban landscape, spearheading a transformational change in sustainability, liveability and climate resilience.

Dubai’s Green Paths to Future initiative was conceived to address the pressing challenges of rapid urbanisation causing desertification, urban heat islands and high energy consumption. Desertification leads to arable land loss and biodiversity decline. Urban heat islands worsen scorching temperatures, impacting health and increasing cooling energy use. Some sources say that over the next century cities such as Dubai may become unlivable as they will be too hot to sustain human life.

Related: Neste works with Dubai for SAF

Industrial areas add air pollution, heat emissions, greenhouse gases and water stress. They disrupt habitats, worsen air quality and strain resources. For Expo 2020, Dubai planted over twenty thousand trees, covering 2.3 million m2, mitigating desertification, enhancing air quality and reducing soil erosion. Addressing industrial impact was crucial for a sustainable Expo and a better Dubai.

We’d like to see more trees planted. Although the Dutch company Airshades is a low-energy idea to provide shade for residents in Dubai, natural cover by trees will be better for beauty, climate change, and overall health.

Trees provide roots systems to absorb water that can dampen the effects of unprecedented, torrential rainfalls that put parts of the United Arab Emirates underwater last week, bringing Dubai to a standstill.

Green paths and tree planting mean sustainable, accessible green pathways that offer residents and visitors an enhanced quality of life while combating the urban heat island effect, boosting air quality, and fostering a more vibrant urban environment.

The initiative’s design draws from innovative strategies. It incorporates sustainable landscaping with drought-resistant plant species, integrates modular elements for adaptability, and employs intelligent irrigation systems for efficient water usage. The project is a balance of large infrastructure insertion in a city fabric blended with the landscape to balance and enhance a sustainable design approach.

The results of the Green Paths to Future initiative are both measurable and remarkable. Over 20,000 trees were planted, and more than four million seedlings are strategically placed around roadsides leading to the Expo 2020 venue, effectively creating a new green urban landscape. Beyond its aesthetic impact, the initiative has tangibly improved air quality and introduced sustainable urban mobility solutions.

With Expo 2020 Dubai being a catalyst, the initiative has addressed immediate challenges and created a legacy that contributes to Dubai’s long-term goals. The collaborative effort between governmental bodies, private sector stakeholders and the community showcases Dubai’s commitment to holistic sustainability. The initiative’s success has attracted global events like the UN Climate Change Conference of Parties (COP28), highlighting its impact on the City’s international standing.

Moreover, our landscape projects have a profound impact across social, economic and environmental domains, backed by air quality tests for quantifiable data. Socially, green enhancements improve air quality, enhancing public health and fostering community interaction, enriching the quality of life for all.

Economically, these projects raise property values, attracting tourism and commerce, bolstering local businesses, and reducing healthcare costs through improved air quality, leading to sustained economic growth. Environmentally, our initiatives combat air pollution, sequester carbon and mitigate urban heat islands, aligning with climate goals and enhancing biodiversity.

These projects align with Dubai’s 2040 Urban Master Plan, UAE’s UN Sustainable Development Goals, and national sustainability agendas, positioning Dubai as a pioneering green city.

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We’ve written about the benefits of white paint on a hot tar roof in the past, at least a couple of times. And the fact that they can’t slow global warming.  White paint is what people paint the roofs of their apartment buildings in Tel Aviv to keep the insides cool. It’s certainly something that designers and architects in the Middle East already know and that’s why mashrabiya were invented.

People in the Middle East or Texas who don’t want to enter an inferno 6 months of the year buy white cars. And if you have a black roof home or even a panel of glass windows that face the sun, expect to have your air conditioner bill go through the roof for 6 months of the year.

Some more research from Purdue and a “new” white paint, which is the whitest of the white paint, explores just how much you can save by painting your roof white. This is a great idea for energy savings on large industrial buildings, schools, hospitals, factories and government buildings looking to lower energy costs. They say that their experimental paint is so effective you might never need to turn your air con on. And after the new white roof? Maybe a rooftop garden? Solar energy panels?

Back over to the study: Purdue University engineers have created white paint that can keep surfaces up to 18 degrees Fahrenheit cooler than their ambient surroundings – almost like a refrigerator does, but without consuming any energy. We call this passive cooling. 

According to the researchers, the paint would replace the need for air conditioning by absorbing nearly no solar energy and sending heat away from the building. Without the building heating up, air conditioning wouldn’t have to kick on.

“It’s very counterintuitive for a surface in direct sunlight to be cooler than the temperature your local weather station reports for that area, but we’ve shown this to be possible,” said Xiulin Ruan, a Purdue professor of mechanical engineering.

The paint not only sends heat away from a surface, but also away from Earth into deep space where heat travels indefinitely at the speed of light. This way, heat doesn’t get trapped within the atmosphere and contribute to global warming. 

Sci Fi White Paint Video:

“We’re not moving heat from the surface to the atmosphere. We’re just dumping it all out into the universe, which is an infinite heat sink,” said Xiangyu Li, a postdoctoral researcher at the Massachusetts Institute of Technology who worked on this project as a Ph.D. student in Ruan’s lab.

Earth’s surface would actually get cooler with this technology if the paint were applied to a variety of surfaces including roads, rooftops and cars all over the world, the researchers said.

In a paper published Wednesday (Oct. 21) in the journal Cell Reports Physical Science, the researchers show that compared with commercial white paint, the paint that they developed can maintain a lower temperature under direct sunlight and reflect more ultraviolet rays.

Their proof is infrared camera images taken of the two paints in rooftop experiments.

“An infrared camera gives you a temperature reading just like a thermometer would to judge if someone has a fever. These readings confirmed that our paint has a lower temperature than both its surroundings and the commercial counterpart,” Ruan said.

Reflects most of the sun’s heat

Commercial “heat rejecting paints” currently on the market reflect only 80% to 90% of sunlight and cannot achieve temperatures below their surroundings. The white paint that Purdue researchers created reflects 95.5% sunlight and efficiently radiates infrared heat.

Developing this paint formulation wasn’t easy. The six-year study builds on attempts going back to the 1970s to develop radiative cooling paint as a feasible alternative to traditional air conditioners.

Making the whitest of the white from seashells

The researchers considered over 100 different material combinations, narrowed them down to 10 and tested about 50 different formulations for each material. They landed on a formulation made of calcium carbonate, an earth-abundant compound commonly found in rocks and seashells.

This compound, used as the paint’s filler, allowed the formulation to behave essentially the same as commercial white paint but with greatly enhanced cooling properties. These calcium carbonate fillers absorb almost no ultraviolet rays due to a so-called large “band gap,” a result of their atomic structure. They also have a high concentration of particles that are different sizes, allowing the paint to scatter a wider range of wavelengths.

According to the researchers’ cost estimates, this paint would be both cheaper to produce than its commercial alternative and could save about a dollar per day that would have been spent on air conditioning for a one-story house of approximately 1,076 square feet.

“Your air conditioning kicks on mainly due to sunlight heating up the roof and walls and making the inside of your house feel warmer. This paint is basically creating free air conditioning by reflecting that sunlight and offsetting those heat gains from inside your house,” said Joseph Peoples, a Purdue Ph.D. student in mechanical engineering and a co-author of the work.

Cutting down on air conditioning also means using less energy produced by coal, which could lead to reduced carbon dioxide emissions, Peoples said. The researchers have further studies underway to evaluate these benefits.

Environmental artist and designer Pablo Solomon lives in the hot and arid American state of Texas. He doesn’t believe that white paint could put air conditioners out of commission in Houston:

“While painting surfaces white does reflect sunlight, it will not replace AC in Houston, Texas. Having lived much of my early life there, the heat is made more miserable by the high humidity. Also, although Houston is 50 miles inland from the Gulf of Mexico, it is usually the first or second port by tonnage in the US due to it being accessible by the Houston Ship Channel being dredged from Buffalo Bayou and the San Jacinto River,” he tells Green Prophet.

He notes: “Houston’s weather is totally dominated and kept at subtropical warmth by the Gulf of Mexico. Normal humidity hovers around 80 plus percent. Downtown Houston is barely 50 feet above sea level and many of the suburbs toward the coast are less than that. Add all of the steel and concrete of America’s 4th largest city and AC is not a luxury, but a requirement.

“Thank heavens that new high efficiency AC units, double/triple paned windows and improved insulation cut energy use a lot. Also to put things in perspective, if you spin your home globe, you will see that Houston is the same latitude as Cairo and Saigon.”

___ 

Have a passive energy solution to report? Email me karin@greenprophet.com

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It can get hot enough in the Middle Eastern sun to fry an egg outside. If you’ve spent even a small amount of time in either Abu Dhabi or any other Gulf countries in summer, you know that it’s stifling hot outside and freezing cold inside just about every building. New paint may be able to reduce cooling loads by 20 percent – at least according to research from Watergy International Group.

Related: SolCold paint cools cars and buildings passively

Watergy is working with researchers at Masdar Institute just outside of Abu Dhabi to test a new paint that is applied to rooftops.

They applied the paint, which contains titanium dioxide (a material that is used in sunscreen) to a 2, 120 square foot area of roof at the Masdar Field station. Areas of the same roof were painted grey and one area was left uncovered.

At 9:30am, when it’s already blazing hot outside, the researchers found that the areas painted white measured just 76.82 degrees Fahrenheit, whereas the uncovered areas were unbearable to walk on at 116 degrees Fahrenheit.

Peter Armstrong, associate professor of mechanical engineering at Masdar Institute, told The National that white paint makes the most sense, but that grey and black paint containing the same chemicals would also be effective if it is required for stylistic reasons.

“It is best to have white on the roof because no one can see it up there,” he said.

In addition to reducing the heat island effect associated with buildings that have soaked up a great deal of solar energy and then radiate that heat, alongside cars and other energy sources, the paint could reduce the need to cool homes with air-conditioning.

Armstrong says that uninsulated concrete villas would benefit the most from the paint.

“Villas would benefit greatly. In a typical villa the AC unit is up on the roof so when you limit the heat on the roof you improve the performance of the AC because now where the AC is, it is a lower temperature,” he told the paper. “The higher the temperature is where AC is trying to reject the heat the lower the performance.”

A hangar in Sharjah and a supermarket in Italy already benefit from the cooling paint.

The next step in Abu Dhabi, for which Watergy has signed a letter of agreement to the tune of nearly $3 million, is to test two 50,000 square meter areas in the city.

After that, the paint could be applied to a variety of surfaces in order to bring down over all temperatures – even roads.

White cars, likewise, hold more value in hot countries (link). But before you go out and buy cans of white paint, you might want to think about the climate. According to this research we covered in 2011, white paint on roof tops contributes to more global warming. The advice from 2011? Put solar panels on your roofs instead.

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