Previous method refined<\/p>\n
It\u2019s long been known that using highly reflective materials for urban surfaces like roofs and pavement can help lower local temperatures and mitigate climate change. Brighter surfaces reflect more solar radiation back into the atmosphere, reducing building energy use and easing the urban \u201cheat island\u201d effect, which makes cities hotter than surrounding areas.<\/p>\n
This reflectivity is measured as \u201calbedo,\u201d on a scale from zero to one, where zero means no reflection and one means all incoming solar radiation is reflected. Most urban areas fall between 0.1 and 0.3, meaning they absorb between 70 to 90 per cent of the sun\u2019s radiation.<\/p>\n
A previous paper<\/a> cowritten by Akbari and professor Damon Matthews<\/a> and researcher Donny Seto<\/a>, both in the Department of Geography, Planning and Environment<\/a>, estimated that raising the albedo of one square metre of surface by 0.01 could offset about 2.5 kilograms of CO\u2082 emissions.<\/p>\n The new research, published in the journal Urban Climate<\/a>, refines this idea by accounting for local conditions such as sunlight intensity and cloud cover, allowing for more precise, location-specific estimates.<\/p>\n Global data for local knowledge<\/p>\n To develop the updated model, Akbari analyzed data from roughly 4,400 weather stations worldwide. By combining solar radiation measurements taken at Earth\u2019s surface with estimates of incoming solar energy at the top of the atmosphere, the researchers were able to determine how much sunlight is reflected back into space in different regions.<\/p>\n The method allows practitioners to estimate CO\u2082 equivalency using standard climate and weather datasets rather than complex simulations.<\/p>\n The findings show that the climate benefit of reflective surfaces varies significantly by location. On average, increasing albedo by 0.01 can offset about 1.8 to 2 kilograms of CO\u2082 per square metre globally, with some regions reaching up to 5 kilograms depending on atmospheric clarity. The effect is strongest in less cloudy regions, particularly around 20 to 30 degrees north and south of the equator, where more solar energy reaches the ground.<\/p>\n No negative impacts<\/p>\n Akbari says this simplified approach could help policymakers and planners better quantify the climate value of \u201ccool roofs\u201d and pavements. By translating reflectivity into CO\u2082-equivalent reductions, the method can be used in developing carbon accounting systems, climate policies and even carbon markets.<\/p>\n \u201cThe beauty of cool surface technology is that we have thousands of years of experience with it, and we do not know of any negative impacts associated with it,\u201d Akbari says. \u201cThere is very little incremental cost, it improves ambient conditions within the city while it cools the planet, and it puts money in your pocket.\u201d<\/p>\n This study received funding from the Natural Sciences and Engineering Research Council of Canada.<\/p>\n <\/a>Read the cited paper: \u201cA simplified method to calculate atmospheric CO2 \u00a0equivalency for changing surface albedo<\/a>\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"Previous method refined It\u2019s long been known that using highly reflective materials for urban surfaces like roofs and…\n","protected":false},"author":2,"featured_media":604826,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[49,48,66],"class_list":{"0":"post-604825","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-ca","9":"tag-canada","10":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/604825","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=604825"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/604825\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/604826"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=604825"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=604825"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=604825"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}