Earth’s material has a varied property of absorbing and reflecting sunlight. From the school’s science book we all have come across the term called the Greenhouse effect, it is the property of re-radiating the sunlight back to the Earth's surface and the gases like carbon dioxide, methane trap the heat which makes the Earth warmer.
The modern world became more comfortable in constructing more buildings for houses, industries, and other commercial uses and India is inhabited mostly in concrete houses. Cement is the essential element in concrete which has great absorbing property, causing heat-trapping in buildings.
Cement, a vital element in modern construction, also accounts for 1/12th of the CO2 released into the atmosphere every year. It is hard to reduce cement from practice, but we can reduce the heat entering down from rooftops into rooms. The way is effortless, workable and economical, which is to paint white on the rooftops.
We may wonder how white paint can protect us from heat. The little science behind the white coating is the Albedo effect. The Albedo effect gives a score for all kinds of a surface on Earth from 0 to 1. The regions with snow cover score 1, which means it is an entirely reflective surface. Painting white on our terraces reflects the entire heat incident upon the buildings.
Cities like Ahmadabad, Hyderabad, Gujarat and Bangalore have turned solar reflective. India uses a lot of air conditioning to maintain a cooler indoors, which increases more heat by releasing greenhouse gases and also hikes electricity bill.
A study conducted in Berkeley Lab showed that if the use of reflective roofing globally, could produce a global cooling effect equivalent to offsetting 24 Gigatons of carbon dioxide- the equivalent of taking 300 million cars off the road for 20 years. A minor change can bring a tremendous impact. People who can afford to paint white on the roof can take this little step towards reducing global warming. Families can also do painting white as a fun activity with kids before the hot summer begins.
White is the new green, so let us all convert our urban heat islands of India into the Islands of Santorini!
Written by: Manju Pargavi