Painting roofs white can reflect the sun's heat and prevent thousands of deaths in cities during heatwaves

Cities can heat up by an extra 9°C (16°F) compared to surrounding areas  


 

Cities can heat up by an extra 9°C (16°F) compared to surrounding areas - an effect called the 'urban heat island'. But painting roofs in colours that reflect heat back into space, like in Santorini, pictured, can keep buildings significantly cooler


Painting roofs in bright colours can reflect heat back into space 

This keeps the cities cooler than if the heat from the sun was absorbed  

Around half of deaths during heatwaves - mainly the elderly - are thought to be caused by the extra heat in cities




 

흰색 지붕, 태양열 반사 효과...폭염 사망자 줄일 수 있어


옥스포드대 연구결과


지붕을 하얗게 칠하면 매년 폭염으로 수천 명의 생명을 막을 수 있다고 새로운 연구결과가 나왔다.

도시는 주변 지역에 비해 9°C(16°F) 더 뜨거워질 수 있는데, 이것을 '도시 열섬'이라고 한다.


지붕을 흰색으로 칠하는 것은 건물을 매우 시원하게 유지할 수 있다는 연구 결과가 나왔다.

폭염에 사망의 절반 정도 차지하는  주로 노인들, 이는 도시에서의 폭염에 의한 것으로 기인한다.


옥스포드 대학의 연구는 '열섬' 효과는 도시의 수분과 식물의 부족과 도시 건축 재료가 열을 저장하기 때문에 발생한다고 말했다.




과학자들은 2003년과 2006년의 무더운 여름에서 볼 수 있는 열 수준을 시뮬레이션하면서 버밍엄 시의 기온이 얼마나 떨어질지를 계산했다.


국제환경 조사에 따르면 도시의 지붕을 흰색으로 바꿀 경우 약 3도의 열을 저하시킬 수 있다고 한다. 이는 도시의 상업 및 산업시설 절반이 이를 이행해야 가능한 수치다.


이런 경우 폭염으로 인한 사망자수를 25% 정도 줄일 수 있다.


황기철 콘페이퍼 에디터 큐레이터

Ki Cheol Hwang, conpaper editor, curator


edited by kcontents


By COLIN FERNANDEZ SCIENCE CORRESPONDENT FOR THE DAILY MAIL

PUBLISHED: 13:41 BST, 5 April 2019 | UPDATED: 14:02 BST, 5 April 2019

Thousands of lives lost each year in heatwaves could be prevented by painting roofs white, new research suggests.


Cities can heat up by an extra 9°C (16°F) compared to surrounding areas - an effect called the 'urban heat island'.

But painting roofs in colours that reflect heat back into space can keep buildings significantly cooler, research has found.




Scroll down for video  


Around half of deaths during heatwaves - mainly the elderly - are thought to be caused by the extra heat in cities.

Experts calculate how many people die during heatwaves, compared to how many would die normally.


For example, the 2003 heatwave is thought to have caused the deaths of 2,000 people in England and in July 2009 a four-day spell of hot weather killed 300 people.


The Oxford University study said the 'heat island' effect is caused partly by a lack of moisture and vegetation in cities compared with rural landscapes, and because urban building materials store up heat.


The scientists calculated how much temperatures would drop in the city of Birmingham, simulating heat levels seen in the hot summers of 2003 and 2006.


The study, published in Environment International, suggested that implementing cool roofs across the city can reduce peak daytime local temperatures by up to 3c during a heatwave.


To achieve this reduction would require around half of the commercial and industrial buildings in the city to paint their roofs.


This reduction in temperature could potentially offset around 25 per cent of the heat-related mortality associated with the urban heat island during a heatwave.


 

Around half of deaths during heatwaves - mainly the elderly - are thought to be caused by the extra heat in cities. For example, the 2003 heatwave is thought to have caused the deaths of 2,000 people in England and in July 2009 a four-day spell of hot weather killed 300 people (stock)


Applied worldwide it would lead to reductions of thousands of deaths, the research suggests.


The urban heat island effect is most pronounced at night time, because urban materials slowly release their stored heat overnight, however, the biggest benefits of cool roofs were seen to be during the hottest part of the day where sunlight was reflected away.


Co-author Dr Clare Heaviside, of the University of Oxford's Environmental Change Institute comments: 'Climate change and increasing urbanisation mean that future populations are likely to be at increased risk of overheating in cities, although building and city scale interventions have the potential to reduce this risk.


'Modelling studies like this one can help to determine the most effective methods to implement in order to reduce health risks in our cities in the future.' 


View Full Text

https://www.dailymail.co.uk/sciencetech/article-6890601/Covering-roofs-light-colours-reflect-heat-sun.html


kcontents


 
 
 
Posted by engi, conpaper engi-