Why in news
In a paper published in Science, researchers from the University of Chicago detail a new wearable fabric that can help urban residents survive the worst impacts of massive heat caused by global climate change, with applications in clothing, building and car design, and food storage.
Urban areas usually experience the urban heat island effect, that is, they are significantly warmer than surrounding rural areas.
The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak, under block conditions, noticeably during the summer and winter
Its Implications
In tests sun, the new material kept:
2.3°C cooler than broadband emitter fabric used for outdoor endurance sports.
8.9°C cooler than commercialised silk commonly used for summer clothing.
The team hopes this material will help reduce heat-related hospitalisations and deaths.
Existing cooling fabrics for outdoor sports reflect the sun’s light diffusely to avoid blinding onlookers.
In urban heat islands, thermal radiation from buildings and pavement adds to the heat.
97% of clothes are heated by thermal radiation from sides and below, which broadband emitter fabric does not combat.
Many materials that perform well in lab tests are ineffective in real urban heat conditions like those in Arizona, Southeast Asia, and China during massive heat waves.
Applications of the new fabric extend beyond clothing:
A thicker version, protected by polyethylene, could be used on buildings or cars to lower internal temperatures and reduce air conditioning costs and carbon impact.
The material could also be used for transporting and storing milk and other perishable foods, reducing refrigeration's environmental impact.
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