Rooftop Innovations: Cooling Cities and Resilient Crops

A rooftop revolution is quietly taking shape in the lab and in the desert — from plants that shield themselves from blistering heat to paint that can cool a city block and pull water from thin air.

At King Abdullah University of Science and Technology (KAUST), researchers have zeroed in on how plants keep photosynthesis alive when temperatures soar, a discovery that could reshape farming in some of the harshest climates on Earth.

Led by Professor Monika Chodasiewicz, the team uncovered a protective mechanism inside chloroplasts, the tiny powerhouses in plant cells that turn sunlight into chemical energy. Under high heat, a chlorophyll protein forms protective granules, a behavior whose purpose had remained murky. Those granules, the study shows, help preserve and restore the plant’s ability to photosynthesize when conditions turn hostile.

This is not a niche curiosity. Heat ranks among the most destructive forces for plant productivity, burning away yields and stunting growth. Guarding photosynthesis, Chodasiewicz noted, is central to keeping crops alive and productive as the mercury climbs.

The work does more than explain a clever plant trick. It opens a new line of attack for breeders and biotechnologists trying to toughen crops for desert and semi-arid regions. By understanding and potentially enhancing this granular defense system, scientists could engineer varieties that keep producing under the kind of temperatures that now wipe out harvests.

The findings also plug into a fast-growing field: phase-separated biomolecular condensates in plant biology. These tiny, dynamic clusters inside cells are emerging as key organizers of cellular life. Showing that such condensates help protect photosynthesis ties cutting-edge cell biology directly to global concerns — sustainable agriculture, climate adaptation, and food security.

While KAUST scientists probe the inner life of leaves, a different group of researchers is looking up — to rooftops.

In Australia, a team at the University of Sydney has turned a simple idea into a potentially transformative climate tool: a nanoengineered paint that can cool buildings and harvest water from the air.

For scientists Chiara Neto and Ming Chiu, the starting point was familiar: cities are heating up. Concrete, asphalt, and conventional rooftops soak in sunlight, store it, and radiate it back, creating urban heat islands where temperatures sit stubbornly higher than in surrounding rural areas. Add worsening water scarcity, and the challenge is brutal.

Their answer was deceptively modest — a rooftop coating. But not just any white paint.

Spun out into a startup, Dewpoint Innovations, in 2022, the project aims to rethink what a roof can do. If enough surfaces across a city could reflect heat and pull moisture from the air, rooftops would stop being passive slabs and start working as part of the climate solution.

“Our paint will significantly reduce the heat load the sun puts on cities,” said Chiu, now co-inventor and chief technology officer at Dewpoint Innovations.

The coating relies on passive radiative cooling. Specially engineered nanomaterials reflect most of the sun’s energy while sending heat away into the sky, allowing roof surfaces to stay cooler than the surrounding air — without consuming electricity.

Typical commercial white paint reflects around 70% to 80% of incoming sunlight, according to Distinguished Professor Baohua Jia, a nanotechnology expert at RMIT University in Melbourne, who is not involved with Dewpoint Innovations. That’s decent. But not game-changing.

Dewpoint’s coating pushed that figure dramatically higher. In a six-month outdoor trial reported in 2025, the paint achieved solar reflectance of up to 96%. The impact was immediate and measurable: with so much less energy absorbed, roof surfaces stayed as much as 6 degrees Celsius cooler than the surrounding air.

Cooler roofs mean less demand for air conditioning, lower energy bills, and reduced strain on power grids during heatwaves. In water-stressed regions, the paint’s ability to help collect moisture from the air adds another layer of resilience.

From chloroplasts shielding fragile photosynthetic machinery to rooftops bouncing heat back into the sky, the same story runs through both breakthroughs: survival in a warming world will depend on ingenuity at every scale — from the nanoscale granule inside a leaf to the citywide patchwork of reflective roofs overhead.