Cities around the world are getting hotter as the planet warms, and the consequences can be deadly. Researchers have linked heat waves like the one that hit Russia in 2010killing 55,000 peopleto climate change. And even without global warming, cities tend to bake when the weather gets warm. Surfaces such as asphalt roads and concrete buildings absorb and then radiate a lot of solar energy, which can leave urban areas 6 to 8 degrees Celsius warmer than rural regions.
Although some people can just crank up the air-conditioning amid increasingly brutal heat, many cannot. Urban decision makers need to know where to focus resources as they plan their adaptation strategies, potentially as a matter of life and death. But how can they pinpoint the most vulnerable populations? In a recent study researchers answered this question for Philadelphia by mapping the places where residents are most at risk.
For their paper, published in Applied Geography, researchers at the Earth Institute at Columbia University and Battelle Memorial Institute studied air temperature data from weather stations, land surface temperatures measured by satellites and socioeconomic data. First they used the weather station data to determine how temperatures in Philadelphias urban and surrounding rural areas had changed over time. They found the number of extreme heat event days in the city had risen threefold from about four in 1980 to nearly 12 in 2013. The nearby rural areas experienced no change over the same period, remaining at five extreme heat event days per year. The authors defined a heat event as three or more successive days in which the 24-hour daily mean temperature rose above a certain historical average high for July and Augustin Philadelphias case, 27 degrees Celsius. That means that it is staying hot all day and all night, with no relief for three or more days, explains Stephanie Weber, a principal research scientist at Battelle and one of the study co-authors. Its not the hottest temperature, but something that when it is sustained and without relief during the night [and] early morning can pose serious health risks.
The researchers also found the urban areas experienced a huge increase in the number of hotter than normal nightswhich actually decreased in the rural areas over the same period. This is significant for city dwellers health, says Alex de Sherbinin, one of the study authors and associate director of science applications at the Earth Institutes Center for International Earth Science Information Network. Whats perhaps the most important for heat stress in these urban environments is what goes on at night, he explains. Its the cooling at night thats important for the elderly and others who are not living in air-conditioned circumstances. De Sherbinin notes the research did not tease apart how much these trends were caused by the urban heating effect versus climate change.
De Sherbinin and his teamWeber, Natasha Sadoff and Erica Zellthen mapped where Philadelphias most heat-sensitive populations live. They looked at factors including income, education level and households of people over age 65 who live alone. They combined this information with the land surface temperatures measured by satellite and found that more than half a million peopleabout 10 percent of the populationinhabit neighborhoods that are most vulnerable to heat event health impacts.
Experts who were not involved in the project note it did not consider some factors that might better identify the most vulnerable populations. I would have encouraged someone doing this type of study to look for indicators of social cohesion and connectionsfor institutions like churches, whose members, for example, might have social contacts who can shelter them in emergencies, explains Jason Corburn, who directs the Institute of Urban and Regional Development and the Center for Global Healthy Cities at the University of California, Berkeley. In a heat event those factors matter for vulnerability. They also matter for people getting information about whether a heat event is coming. Corburn also thinks the researchers should have included city-level health data in their assessment.
Another expert, Brian Stone, director of theUrban Climate Labat Georgia Institute of Technology, thinks satellite land surface temperatures are not a reliable measure for the heat people experiencethese measurements gauge the temperature at the sidewalk level, rather than a meter or two above it. The difference can be significant. Sherbinin, however, believes his teams method is reasonable. Using land surface temperature [data] to define themost heat-exposed neighborhoods I believe is completely justified, since this is a relative measure of the most heat-impacted neighborhoods, he wrote in an e-mail. Matei Georgescu, associate director of the School of Geographical Sciences and Urban Planning at Arizona State University, explains that even though satellite-measured land surface temperatures may not be an ideal indicator, this limited data can still help answer research questions. I think the work is a useful step in trying to understand where and how cities should be managing their particular neighborhoods, in terms of who is exposed and what the sensitivities are, he says.
De Sherbinin and his team also worked with local officials, academics and others for their study, and presented their results to a Philadelphia advisory group at the end. Equipped with this sort of information, city planners can better design cities by creating green spaces or building cooling centersplaces where those lacking air conditioners can shelter during extreme weatherin the most heat-vulnerable neighborhoods. They could also offer better social services to the most sensitive populations. In the future de Sherbinin hopes to apply this approach to other parts of the U.S. and beyond, in cities such as Shanghai and Mumbai.
Read more here:
Too Sunny in Philadelphia? Satellites Zero in on Dangerous Urban Heat Islands - Scientific American
- Water Purification Island - November 8th, 2009 [November 8th, 2009]
- Private Islands: South China Sea Style - November 8th, 2009 [November 8th, 2009]
- The Best of Fiji - November 8th, 2009 [November 8th, 2009]
- High Cay: Bahamas - November 8th, 2009 [November 8th, 2009]
- The World: Back on the Market - November 8th, 2009 [November 8th, 2009]
- The Island Market is Back - November 8th, 2009 [November 8th, 2009]
- Haunted Halloween Island - November 8th, 2009 [November 8th, 2009]
- Ambergris Island Property - November 8th, 2009 [November 8th, 2009]
- Paradise Sinking - November 8th, 2009 [November 8th, 2009]
- Parrot Cay: Own a Piece of Privacy - November 8th, 2009 [November 8th, 2009]
- An Icky Day - November 8th, 2009 [November 8th, 2009]
- It's a Cory's! - November 8th, 2009 [November 8th, 2009]
- There she blows! - November 8th, 2009 [November 8th, 2009]
- Bye bye Whale - November 8th, 2009 [November 8th, 2009]
- No Bunting Mistake - November 8th, 2009 [November 8th, 2009]
- Whale of a time... - November 8th, 2009 [November 8th, 2009]
- Leaving day - November 8th, 2009 [November 8th, 2009]
- Look who's back... - November 8th, 2009 [November 8th, 2009]
- Lanced... - November 8th, 2009 [November 8th, 2009]
- Migrants role in... - November 8th, 2009 [November 8th, 2009]
- Pups away! - November 8th, 2009 [November 8th, 2009]
- Double take - November 8th, 2009 [November 8th, 2009]
- Northerly wind blows - November 8th, 2009 [November 8th, 2009]
- Northern visitors - November 8th, 2009 [November 8th, 2009]
- Siege! - November 8th, 2009 [November 8th, 2009]
- Storm time - November 8th, 2009 [November 8th, 2009]
- Storm season - November 8th, 2009 [November 8th, 2009]
- Storming over - November 8th, 2009 [November 8th, 2009]
- Sealing mission - November 8th, 2009 [November 8th, 2009]
- Still no go - November 8th, 2009 [November 8th, 2009]
- Over they go! - November 8th, 2009 [November 8th, 2009]
- All change - November 8th, 2009 [November 8th, 2009]
- Welcome back storms - November 8th, 2009 [November 8th, 2009]
- Fight club - November 8th, 2009 [November 8th, 2009]
- V Australia to Fiji - November 8th, 2009 [November 8th, 2009]
- Tahiti Sun Travel For Sale - November 8th, 2009 [November 8th, 2009]
- Cook Islands Travel Guide - November 8th, 2009 [November 8th, 2009]
- Perfectly Frank – Fiji - November 8th, 2009 [November 8th, 2009]
- Cook Islands Tax Hike - November 8th, 2009 [November 8th, 2009]
- Easter Island Travel Guide - November 8th, 2009 [November 8th, 2009]
- Surviving Paradise - November 8th, 2009 [November 8th, 2009]
- Canada Seal Hunt ‘09 - November 8th, 2009 [November 8th, 2009]
- Tuvalu Travel Guide - November 8th, 2009 [November 8th, 2009]
- Saudi Arabian Sojourn - November 8th, 2009 [November 8th, 2009]
- Laurent Pichot on Moorea - December 13th, 2009 [December 13th, 2009]
- The Largest Island for Sale in the World. - December 13th, 2009 [December 13th, 2009]
- Isla Kiniw: Incredible Island Rental - December 13th, 2009 [December 13th, 2009]
- Save at Sandals Resorts - December 13th, 2009 [December 13th, 2009]
- Marvelous Mediterranean: Skyropoula Island - December 13th, 2009 [December 13th, 2009]
- Branson Talks Necker Island - December 13th, 2009 [December 13th, 2009]
- Hog Island: Affordable Nova Scotia - December 13th, 2009 [December 13th, 2009]
- The Banyan Tree: Seychelles - December 13th, 2009 [December 13th, 2009]
- Celebrity Secret Vacation Spots - December 13th, 2009 [December 13th, 2009]
- Star Island - December 13th, 2009 [December 13th, 2009]
- 7 Islands in 7 Days - December 13th, 2009 [December 13th, 2009]
- Counting continues - December 13th, 2009 [December 13th, 2009]
- Life goes on - December 13th, 2009 [December 13th, 2009]
- Payback time - December 13th, 2009 [December 13th, 2009]
- No let up - December 13th, 2009 [December 13th, 2009]
- Game on - December 13th, 2009 [December 13th, 2009]
- Deal or No Deal? - December 13th, 2009 [December 13th, 2009]
- Food glorious food - December 13th, 2009 [December 13th, 2009]
- Mainland beckons... - December 13th, 2009 [December 13th, 2009]
- The tempest is coming - December 13th, 2009 [December 13th, 2009]
- Tought times ahead - December 13th, 2009 [December 13th, 2009]
- Tystie day - December 13th, 2009 [December 13th, 2009]
- Saying Goodbye...maybe - December 13th, 2009 [December 13th, 2009]
- Departure Day - December 13th, 2009 [December 13th, 2009]
- Seal pups - December 13th, 2009 [December 13th, 2009]
- Seabird Breeding Season 2009 - December 13th, 2009 [December 13th, 2009]
- Maritime Terminal Papeete Tahiti - December 13th, 2009 [December 13th, 2009]
- A splash of colour - December 14th, 2009 [December 14th, 2009]
- Tiger Woods Wife purchases Island Retreat - December 15th, 2009 [December 15th, 2009]
- New Flights to Fiji - December 18th, 2009 [December 18th, 2009]
- Five Star Fiji - December 19th, 2009 [December 19th, 2009]
- Go Farther in Nicaragua - December 19th, 2009 [December 19th, 2009]
- Zoo Island - December 21st, 2009 [December 21st, 2009]
- Seasons Greetings 2009 - December 23rd, 2009 [December 23rd, 2009]
- Green Ark Island - December 23rd, 2009 [December 23rd, 2009]
- Merry Christmas! - December 25th, 2009 [December 25th, 2009]