Remember when I measured the UHI in Reno, NV? It seems the normally alarmist “Climate Central” is just now getting around to recognizing UHI, but of course, they have to put in the obligatory disclaimer that it cannot possibly contribute to the global warming signal. Well, they are just flat wrong about that, but that’s what they are paid to say.
New Study on Urban Heat Islands and Climate Change Shows Most Large U.S. Cities Getting Hotter Faster than Rural Areas
Since 1970, summer temperatures have been rising. While exact rates of warming differ between regions, most cities have been heating up faster than adjacent rural areas all across the United States. The concrete and asphalt surfaces in city buildings, roads, and infrastructure hold more heat and release that heat more slowly than vegetation and organic surfaces. This is known as the Urban Heat Island (UHI) effect. Climate change then takes that heat and makes cities even hotter.
In a new report, Climate Central analyzes how UHI and climate change have affected 60 of the biggest American cities since 1970. The study examines the difference between average summer temperatures in urban areas and nearby rural areas. Some cities had much higher temperature differences: 23 different cities experienced single days that were an astonishing 20°F warmer than the rural areas around them.
With more than 80% of Americans living in cities, these urban heat islands, combined with rising temperatures caused by increasing heat-trapping greenhouse gas emissions, can cause serious health effects for hundreds of millions of people during the hottest months of the year. Heat is the number one weather-related killer in the United States, and the hottest days, particularly days over 90°F, are associated with dangerous ozone pollution levels that can trigger asthma attacks, heart attacks and other serious health impacts.
The study ranks the 60 cities by the intensity of their heat island effect, shows how heat drives air pollution (ozone levels) in nearly every city analyzed, lists cities that have far more days over 90°F than adjacent rural areas, and shows how most cities are warming faster than the surrounding rural areas.
analysis of summer temperatures in 60 of the largest U.S. cities found that:
- 57 cities had measurable urban heat island effects over the past 10 years. Single-day urban temperatures in some metro areas were as much as 27°F higher than the surrounding rural areas, and on average across all 60 cities, the maximum single-day temperature difference was 17.5°F.
- Cities have many more searing hot days each year. Since 2004, 12 cities averaged at least 20 more days a year above 90°F than nearby rural areas. The 60 cities analyzed averaged at least 8 more days over 90°F each summer compared to adjacent rural areas.
- More heat can increase ozone air pollution. All 51 cities with adequate data showed a statistically significant correlation between higher daily summer temperatures and bad air quality (as measured by ground-level ozone concentrations). Temperatures are being forced higher by increasing urbanization and manmade global warming, which could undermine the hard-won improvements in air quality and public health made over the past few decades.
- In two thirds of the cities analyzed (41 of 60), urbanization and climate change appear to be combining to increase summer heat faster than climate change alone is raising regional temperatures. In three quarters (45 of 60) of cities examined, urbanized areas are warming faster than adjacent rural locations.
- The top 10 cities with the most intense summer urban heat islands (average daily urban-rural temperature differences) over the past 10 years are:
- Las Vegas (7.3°F)
- Albuquerque (5.9°F
- Denver (4.9°F)
- Portland (4.8°F)
- Louisville (4.8°F)
- Washington, D.C. (4.7°F)
- Kansas City (4.6°F)
- Columbus (4.4°F)
- Minneapolis (4.3°F)
- Seattle (4.1°F)
- On average across all 60 cities, urban summer temperatures were 2.4°F hotter than rural temperatures.
Urban heat islands are even more intense at night. Over the past 10 years, average summer overnight temperatures were more than 4°F hotter in cities than surrounding rural areas.
Urban heat measured by satellite in Louisville, Ky. Click image to enlarge.
Several independent studies have shown that urban heat islands (in the U.S., and around the world) do not bias global warming measurements, ruling out the possibility that rising global temperatures have been caused by urbanization alone.
Research suggests that urban planning and design that incorporates more trees and parks, white roofs, and alternative materials for urban infrastructure can help reduce the effects of urban heat islands.
But rising greenhouse gas emissions are projected to drive average U.S summer temperatures even higher in the coming decades, exacerbating urban heat islands and their associated health risks.
Source: http://www.climatecentral.org/news/urban-heat-islands-threaten-u.s.-health-17919
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OMG! So Global Warming is obviously worse in the cities!!! Where most of the people live!!!
If you just watched the 11 pm local news, you knew all about this.
In Baltimore, where I grew up, city temps were always higher than surrounding Baltimore County. Indeed, the county often saw material snow accumulations during the winter, with little to none in the city.
I experienced this effect vividly in the early 1990s, when I lived in a brick building in Portland, Oregon. It became an oven at night in summer. The surrounding countryside by contrast could be downright cold after the sun went down.
When I flew into Vegas last month, it was 113 F at 9 PM. The surrounding desert was cooler enough for the plane to be buffeted by the thermal differential.
I have lived in Reno for 42 years. Believe me, Reno is no hotter than it was in any of the last four decades. Everybody here knows the Reno airport’s official weather station is the hottest place in the metro area – and why wouldn’t it be? The airport was built on a drained lowland wetland, essentially the lowest place around, and is now surrounded by hundreds acres of concrete, buffeted by jet aircraft exhaust, and also sits adjacent to a busy six-lane freeway.
My home outdoor thermometer, only two miles from the airport, reads consistently four degrees cooler than the official Reno temperature.
It is bad enough this contributes to the warming fantasy, but the adjustments for it are in the same direction, warmer.
Can you guys comment on the BEST papers and how they claim that these UHI account for little if not none of the recorded warming? Its obvious to me that UHI is a real thing, but what impact does it really have on the average warming trend, (or is warming still shown even with the UHI)?
Shouldn’t it be mentioned somewhere that this UHI needs to be backed out of the thermometer data when trying to show the primary and secondary effects of CO2 on climate change? It should also be pointed out that during bitter cold winters a little UHI (like incandescent lights) can be a good thing. My expensive LED lamps do nothing to blunt the chill of Old Man Winter.
I still have yet to be convinced by any study that removes UHI as a contributor to the observed warming over the past 150 years. The longest running sites are all based in and around the largest cities worldwide. This is not just a US phenomenon and anyone claiming such has not looked at the station sites. Ask why the warmist make UHI adjustments to current and past data when they build their models to support their alarmist position.
If ” Heat is the no. 1 weather -related killer in the US”, why do the actual death statistics show that more people die in Winter? Or is this merely normal post-modern science?
Frost Warnings have been issues for areas outside the city….a normal weather release in the fall….repeat each year!
Everyone agrees that the little warming the Earth has experienced over the past 150 years or so is very much concentrated in the northern hemisphere, where almost everyone lives and the vast majority of cities and towns lie. However, the devout warm-mongers continue to deny the connection. Anthony, I trust your are going to challenge the absurd assertion by Climate Central that the analysis of UHI is their original work.
So, as a side question, what would you think the thermometers actually measure; when a city grows arround a weather station over the course of a century ? What does it imply for the temperature records ? 🙂
Any motorcyclist knows all about UHI from practical experience. Perfectly comfortable in the city, freezing to death ten miles outside of town.
we’ll just adjust up for that…………..
Nothing new here. In the 1920’s, when it was hot in the summer, it was common for the “City folk” to take the streetcars to a large park (Swope Park, Kansas City, Mo.) south of the inner city to sleep… with mattresses and kids in tow.
It’s obvious BEST got it wrong on UHI. IIRC, they pretty much dismissed UHI out of hand with investigating it. Anthony’s surfacestation.org project shows that even climate reporting stations outside urban areas are being affected by local siting issues.
The more we learn about UHI, the more we know that the models underestimate it.
this is why meteorologists (at a higher percentage anyway) don’t believe in this GW crap.
On the BBC weather forecast the met office presenter will say something like “a bit chilly tonight, down to 10 degrees in the towns but even colder in the countryside – more like 6 or 7”
The real irony about UHI and climate change is that many “smart urban planning” guidelines seek to get rid of the suburbs and place more people in dense urban environments. Given how much greater UHI trends are than global temperature change, the urban planning “remedy” will subject people to 3x more warming than if they lived in the suburbs.
That’s because they don’t really care about people, they want them where they can control their lives. People need to fight these ‘planners’ so that they can retain the freedoms they are accustomed to.
Ronan Connolly has an excellent paper here, explaining how the GISS procedure for adjusting for UHI is wholly inadequate.
http://notalotofpeopleknowthat.wordpress.com/2014/05/20/is-the-giss-adjustment-for-uhi-adequate/
And remember what Richard Muller wrote:
“Urban areas are heavily overrepresented in the siting of temperature stations: less than 1% of the globe is urban but 27% of the Global Historical Climatology Network Monthly stations are located in cities with a population greater than 50000.”
Reno should be a poster child for UHI. The Reno/Sparks metro area experienced an explosion of growth and urbanization since 1970. The airport runway and taxiways have been much expanded and areas around the airport perimeter have been developed from what was farmland. The adjacent freeway has been widened considerably. Of particular interest is the huge Grand Sierra Resort complex (originally the MGM Grand Hotel) which was built adjacent to the airport in the mid-70s, adding 25 acres of asphalt plus a Vegas-scale casino/hotel.
Your graphic triggered a long-dormant memory from the early 60s of James Blish’s ‘Okie’ SF novels.
Coincidence, or similar tastes in reading?
“Several independent studies have shown that urban heat islands (in the U.S., and around the world) do not bias global warming measurements,…”
yet they are saying,
“This is known as the Urban Heat Island (UHI) effect. Climate change then takes that heat and makes cities even hotter.”
The heat from UHI either makes the climate warmer or it doesn’t.
If I remember correctly, the most recent paper on UHI and global warming found that since UHI had only increased by about 0.01C over the last century, there was no need to adjust city based sensors for UHI.
there is no [measureable] AGW and there is no [measureable] UHI either, when looking at a reasonably sized global sample of weather stations.
Namely, both would [mainly] affect minimum temperatures or at least seriously enhance them. Yet minima are falling and I find a natural curve…
http://blogs.24.com/henryp/files/2013/02/henryspooltableNEWc.pdf
last table, on the bottom