Article in AZ Republic re: ever increasing heat island (Phoenix: how much, neighborhoods)

[locolife]

Originally Posted by Prickly Pear

The only way to stop the heat island is to stop building cheap ugly cookie cutter single family homes in the exurbs and repeating those same cookie cutter homes for miles on end. If we had an urban growth boundary like Portland or something we wouldn't be having this discussion. Nor would we paying for over 500+ square miles of large parking lots and asphalt covered roads. It'd still be hot here, but not nearly as hot.

I’m all for density but that doesn’t fix the UHI problem, it’s well documented in every dense city Tokyo, NYC etc... we should be using material that doesn’t absorb and retain heat and there are a lot of interesting options and Phoenix should be leading the effort on these.

[newtoaz20172]

Problem is, people have to believe in climate change first before they want to accept that Phoenix is getting hotter. There is your battle.

[DetroitN8V]

Originally Posted by newtoaz20172

Problem is, people have to believe in climate change first before they want to accept that Phoenix is getting hotter. There is your battle.

That’s completely incorrect. The heat island effect has nothing to do with climate change.

[Potential_Landlord]

Before we get into a frenzy let's make sure the things we do actually work. For example trees will cool us down from the evaporation effect, but also increase humidity - which keeps temperatures higher overnight. I'd really want to understand the net effect for this and any other measure taken. They may be so marginal that it's not worth it. We have and can always live with the heat island effect. It's not the end of the world. There are much more pressing issues like homeless people, car accidents etc.

[Valley Native]

Originally Posted by Prickly Pear

The only way to stop the heat island is to stop building cheap ugly cookie cutter single family homes in the exurbs and repeating those same cookie cutter homes for miles on end. If we had an urban growth boundary like Portland or something we wouldn't be having this discussion. Nor would we paying for over 500+ square miles of large parking lots and asphalt covered roads. It'd still be hot here, but not nearly as hot.

Not only do concrete, asphalt, and sprawling cookie cutter development contribute to the heat island, but all the rock/gravel yards do as well. What's ironic is how grass lawns are often balked at by environmentalist types and those who think we have a water shortage, but manicured grass lawns have a way of offering a cooling effect. During the peak of summer, neighborhoods with rock lawns are still hot during the evening, but older greenbelt districts like Arcadia and north central Phoenix which still use irrigation are noticeably cooler.

Another reason for the increased temperatures is the lack of agriculture. If you look back on Phoenix weather records from 50 to 100 years ago, overnight low temperatures were distinctly lower while daytime highs were only slightly lower. The combination of a smaller population and abundant agriculture contributed to a drastic drop in temperatures between sunset & sunrise. Now that the Phoenix area has quadrupled in population, become a seemingly endless concrete jungle, and there is hardly any agriculture anymore, this makes a big difference in temperatures.

[hikernut]

Originally Posted by Valley Native

Not only do concrete, asphalt, and sprawling cookie cutter development contribute to the heat island, but all the rock/gravel yards do as well. What's ironic is how grass lawns are often balked at by environmentalist types and those who think we have a water shortage, but manicured grass lawns have a way of offering a cooling effect. During the peak of summer, neighborhoods with rock lawns are still hot during the evening, but older greenbelt districts like Arcadia and north central Phoenix which still use irrigation are noticeably cooler.

Another reason for the increased temperatures is the lack of agriculture. If you look back on Phoenix weather records from 50 to 100 years ago, overnight low temperatures were distinctly lower while daytime highs were only slightly lower. The combination of a smaller population and abundant agriculture contributed to a drastic drop in temperatures between sunset & sunrise. Now that the Phoenix area has quadrupled in population, become a seemingly endless concrete jungle, and there is hardly any agriculture anymore, this makes a big difference in temperatures.

Very true. We live in southern Gilbert where there's still irrigated farmland and some irrigated residential areas. The summer low temps are typically 5-8 degrees cooler than the official lows for Phoenix.

[AZ Manager]

Originally Posted by Prickly Pear

The only way to stop the heat island is to stop building cheap ugly cookie cutter single family homes in the exurbs and repeating those same cookie cutter homes for miles on end. If we had an urban growth boundary like Portland or something we wouldn't be having this discussion. Nor would we paying for over 500+ square miles of large parking lots and asphalt covered roads. It'd still be hot here, but not nearly as hot.

Density doesn't fix the problem, at best it shifts the source of the problem around. Taller buildings provide more surface for the sun to heat up and reduce airflow, the primary reason NYC has a UHI problem. Also, packing a lot of AC units into a small space will add an enormous amount of heat waste into that area. According to an ASU study a few years back AC use already increases night temps by almost 2 degrees fahrenheit.

If we went to reflective roads the heat would just be reflected off the roads and transfer into the buildings which would then increase AC/electricity demand which impacts both UHI and adds carbon emissions. You would have to address the road issues and the building issues at the same time to see any benefit and that isn't very cost effective.

If the solution was as simple as you try to make it then you would think there would be a single example in the world for others to follow. We aren't seeing outrageous temp differences so it really isn't as huge of a problem as some people try to make it and some of the contributing factors will solve themselves over time, buildings becoming more efficient for example.

[49erfan916]

Originally Posted by DougStark

https://www.azcentral.com/story/news...ys/1058557001/

Praise for the County supervisor for bringing this up and making it a priority. The writing is on the wall--We need to create a LOT more shade for future years if this metro is going to still be considered desirable.

I've posted previously about the steps the City of Sacramento has done with their "shade ordinances." I wrote the supervisor about Sacramento's Shade Tree efforts (supplied a link for him.) Haven't heard back from him yet tho.

We're not nearly as hot as you guys. Sacramento summers are not bad, but Phoenix's.....

[locolife]

Originally Posted by hikernut

Very true. We live in southern Gilbert where there's still irrigated farmland and some irrigated residential areas. The summer low temps are typically 5-8 degrees cooler than the official lows for Phoenix.

The raw desert cools off the most which isn’t irrigated or paved, you don’t need irrigation to be cooler.

[locolife]

Originally Posted by Valley Native

Not only do concrete, asphalt, and sprawling cookie cutter development contribute to the heat island, but all the rock/gravel yards do as well. What's ironic is how grass lawns are often balked at by environmentalist types and those who think we have a water shortage, but manicured grass lawns have a way of offering a cooling effect. During the peak of summer, neighborhoods with rock lawns are still hot during the evening, but older greenbelt districts like Arcadia and north central Phoenix which still use irrigation are noticeably cooler.

Another reason for the increased temperatures is the lack of agriculture. If you look back on Phoenix weather records from 50 to 100 years ago, overnight low temperatures were distinctly lower while daytime highs were only slightly lower. The combination of a smaller population and abundant agriculture contributed to a drastic drop in temperatures between sunset & sunrise. Now that the Phoenix area has quadrupled in population, become a seemingly endless concrete jungle, and there is hardly any agriculture anymore, this makes a big difference in temperatures.

You’re basically arguing that the UHI would still be a problem if nobody lived here as the natural vegetation is primarily rocks and gravel but we all know that’s not the case, drive 5 miles out in the desert and it’s much cooler at night. We need to use non-heat absorbing material suited for our climate, be it homes, roads or walls. Arguing the natural style landscaping used is the problem makes no sense.