The American West is figuring out how to keep cool

https://www.bbc.com/future/article/20240613-how-to-cool-down-urban-heat-islands-in-americas-heatwaves

by pseudolus • 2 years ago

50 170 2 years ago

gedy• 2 years ago

Space sun shade? https://en.wikipedia.org/wiki/Space_sunshade

NickC253• 2 years ago

Don't know, but such cities shouldn't be encouraging urban sprawl, should be insisting for solar panels on every roof possible, and at the same time shouldn't be incentivizing people to move there.

I've lived in AZ, and it is nice in the winter, sure. But that's only a few months. It is hot as fuck in the warmer months and I to this day have no idea why people actually live there. the urban sprawl plus the fact that you have to drive everywhere, just blows my mind.

throwaway220325• 2 years ago

Arizona is a bit too warm for me, but a lot of people consider driving to be a positive.

I would rather spend 15 mins in my car than 15 mins on a bus. I'd rather live in a place that is sprawling because then everything is bigger - I'd rather have a large house than a small one, a large garden than a small one, and I'd rather shop at a big box store that is more likely to allow me to be hands on with everything I need vs. a teeny high street shop and ordering online.

I currently live somewhere quite urban and barely spend any time in the walkable/public transportable centre because there's not much I want to do there other than pubs and restaurants.

edit: The responses to my post are kind of weird, I'm not telling you to adopt my preferences.

birdman31312• 2 years ago

At least where I am 10 mins in a car can be up to 1.7 hours in a bus. And the same back.

If it was an apples to apples comparison then I would rather be driven than drive. But its not.

QuercusMax3• 2 years ago

How does that work if everyone wants that? We don't have enough Earths to support 8 billion people living in sprawl.

PaulDavisThe1st6• 2 years ago

Reworded:

I love that my car lets me travel alone and without paying the full cost of the miles I log. I'm either terrified of public transit and/or the experiences I've had on it have generally sucked. I prefer bigger everything because I rarely think about the downsides and externalities, and was told from birth that bigger is better. I prefer a large house as long because I can afford somebody else to clean and maintain it, along with the utility bills and property taxes. I prefer a larger garden under the same conditions. I prefer stores that dominate and distort the market and allow me to avoid human interactions.

bcrosby952• 2 years ago

I'm curious, do you feel the same for places that reach 40F? 30F? Because heating is a bigger problem than cooling when it comes to contributions towards climate change. Why do I only ever see people railing against people living in hot places, rather than people living in cold places?

jedberg4• 2 years ago

It's a lot easier to add heat to survive in a cold place than take away heat in a hot place.

Kinda like how people complain in an office "Can we turn down the thermostat? You can put on a coat but I can't take my skin off".

ssl-36• 2 years ago

I mostly only see people railing against living in hot places that are also deserts.

Unlike Arizona, I don't ever see backlash about people living in Mississippi.

NickC253• 2 years ago

30F or 40F ain't bad. My familial roots are in Western NY, where 30F or 40F in the winter is outrageously hot...effectively T-shirt and shorts weather.

People rail against those living in the desert because there's often no water and the water needed to sustain a growing metropolis just isn't available without spending a ton of money and diverting it away from other population centers. Most cold places do have access to water in much larger quantities. (Most, but certainly not all)

Honestly we should all just live in San Diego, where it's never below 65 and never above 85. Perfect weather.

SoftTalker2• 2 years ago

No real issue with installing solar, but the panels are dark. Won't that contribute to the heat island effect, especially considering that among the remediations proposed are white roofs and pavement?

brianshaler2• 2 years ago

A decade or two ago there was a push to paint as many roofs white as possible, which is why you may intuit dark is bad. Black surfaces convert absorb light energy and convert it into heat. Solar panels do get hot, but part of the point is to turn as much of that light energy as possible into electrical energy.

dyauspitr4• 2 years ago

I much prefer hot af to an icy hellhole. Heating takes up a huge amount of energy and you can’t really do it in an environmentally friendly way unless you get creative. The good thing about the heat is when it’s the hottest, solar panels generate the most energy. It’s a cooling solution that scales itself with the temperature.

PaulDavisThe1st6• 2 years ago

The good thing about the heat is when it’s the hottest, solar panels generate the most energy.

Incorrect. Peak PV efficiency occurs at relatively low temperatures.

Perhaps you mean "when it is hot, there tends to be lots of sunshine, and so there's lot of PV generation" ? That's true of some places (Southern CA, AZ, NV, NM) but less true of others (Louisiana, Alabama, Mississippi, Georgia etc).

accrual• 2 years ago

when it’s the hottest, solar panels generate the most energy

That's not true.

It may seem counterintuitive, but solar panel efficiency is negatively affected by temperature increases. Photovoltaic modules are tested at a temperature of 25° C - about 77° F, and depending on their installed location, heat can reduce output efficiency by 10-25%. As the solar panel's temperature increases, its output current increases exponentially while the voltage output decreases linearly. In fact, voltage reduction is so predictable that it can be used to measure temperature accurately. [0]
Home solar panels are tested at 25 °C (77 °F), and thus solar panel temperature will generally range between 15 °C and 35 °C during which solar cells will produce at maximum efficiency. However, solar panels can get as hot as 65 °C (149 °F), at which point solar cell efficiency will be hindered. [1]

[0] https://www.greentechrenewables.com/article/how-does-heat-af...

[1] https://www.energysage.com/solar/solar-panel-temperature-ove...

hosh12• 2 years ago

I live in Phoenix now. My wife and I are planning to move away from here in two years. We were only here because of circumstances outside of our control and now those circumstances are no longer applicable.

Phoenix's main economic driver is real estate development and speculation since the 60s. It has very little in the way of real wealth that serves as a foundation (other than ASU and the two silicon fabs that are there now). A lot of people come here thinking it is affordable cost of living (and it is not that affordable in 2024), but I don't think many residents here really know why they live in Phoenix either.

toomuchtodo• 2 years ago

Best time to get out of a market is before everyone else is running for the door. Lots of stranded assets and sadness ahead for folks who held on to assets too long in the wrong places.

https://www.marketplace.org/2024/05/28/are-we-in-the-midst-o...

http://www.deltaterracapital.com/

voisin3• 2 years ago

The answer is trees everywhere in numbers that you don’t find in western cities. Like 100x the number of trees normally found in a city. The benefits aren’t just in temperature but also air quality, biodiversity, etc etc.

Edit: for those saying “But there’s not enough water”, I strongly suggest reading “Rainwater Harvesting in Drylands and Beyond” written by Brad Lancaster in Arizona. For those who don’t want to read the book, check out his TED Talk here (warning: his enthusiasm is infectious and you’ll want to read the book afterward): https://m.youtube.com/watch?v=I2xDZlpInik

turnsout2• 2 years ago

Works really well as long as you can find trees that don't consume water.

The challenge in these western cities is that they don't even have enough water to run the taps. The reality is that the western US should not be this populated, period.

ch4s32• 2 years ago

That's exactly what Phoenix is doing[1], well not no water but they're native and use very little.

[1] https://www.phoenix.gov/oepsite/Documents/Tree%20and%20Shade...

vhost-• 2 years ago

I live in Portland, a place covered in trees and there’s definitely plenty of water for them. When I travel through parts of East Portland, it’s very noticeably hotter and there’s a noticeable lack of trees. The problem seems to be part political, part budget and part passing the buck (BUT WHOS GONNA TAKE CARE OF THEM??). It’s very frustrating.

estebank2• 2 years ago

The vast majority of water in western US goes to agriculture. You can of course make the obvious argument about local food production being necessary, but if the choice is more people can drink water at the cost of more expensive almonds and alfalfa, I'm ok with that. The idea that the west has done anywhere close to enough to optimize water consumption is not right, there's quite a bit of headroom left (that should be used to replenish aquifers).

NoMoreNicksLeft• 2 years ago

Treated wastewater is almost waste itself, because at least in the United States we're reluctant to use it for agriculture for the obvious reasons. And trees aren't particularly large consumers of water, because the irrigation methods are non-lossy. Not spraying sprinklers up in the air so half is lost to evap. Or flooding little furrows in between the rows of a crop. It's not that big of a challenge, at least water wise. Infrastructure, if anything, is the problem... cities would have to go digging up a fuckton of sidewalk, and spend extra on maintenance every time there's a leak. Worse still, is having two separate water systems (can't connect to the potable water mains).

eep_social2• 2 years ago

Which cities? Metro Phoenix non-agricultural water usage is flat over the past 30 or 40 years despite experiencing double digit population growth for most of that time. Agriculture is the majority consumer and incentives and stewardship norms are evolving.

oceanplexian• 2 years ago

The desert has always been a place humans needed technology to thrive in, since the ancient Gardens of Babylon or the Phoenix canals constructed by the Native Americans. The challenge is we need to invest in technology (Did you know the AZ border is only 60 miles from the Sea of Cortez?).

There are lots of solutions that don’t involve throwing our hands up and saying “aw shucks it’s too hard to build infrastructure so I guess we should go home”

somenameforme2• 2 years ago

Yip I've lived in many places where you have months of 40C+ (~104F), but when you past through a nice forested area the temperature just instantly plummets.

jedberg4• 2 years ago

Water is the problem. You don't see a lot of trees in southwestern cities because we don't have the water to keep them alive.

DoctorDabadedoo• 2 years ago

I would argue that the problem is maintenance. Trees need to be pruned, watered, checked for pests, can get into sewer lines, waterways, etc. To sum up, they require work and one thing that governments hate is extra work.

somenameforme2• 2 years ago

Something I've seen in many cities around the world (though never once in the US) is cities that essentially integrate literal forests into their layout. It's not the typical aesthetic or small-park type setting with a few dozen neatly sculpted and organized trees that would shortly give way without constant attention, but literal overgrown and completely self-sustaining forests. The closest I could find with an image search was apparently in Melbourne. [1] Imagine something like that, but somewhat more chaotic and natural. It works really well, but runs contrary to the sort of sterile aesthetic that most Western cities generally aim for.

[1] https://i.pinimg.com/originals/ec/c3/09/ecc309a7ebfb8f2235f1...

digital_sawzall• 2 years ago

Yet places like Arizona are famous for their lush green lawns and golf courses.

the__alchemist• 2 years ago

Mendoza handles this by guiding water into the city from nearby mountains. Of course, you have to have suitable nearby mountains to do this... But the city, in a desert, is filled with trees!

SoftTalker2• 2 years ago

Sam Kinison had it right in the 1980s. DON'T LIVE IN THE DESERT!!! OOOHHHH!!!!

dyauspitr4• 2 years ago

We absolutely need to massively scale solar powered desalination plants in hot places. I realize there are issues around releasing high salt content water back into the ocean but there has to be ways to do that effectively. For instance, heavily dilute the high salt outflow with a lot of ocean water before releasing it back into the ocean.

hosh12• 2 years ago

In the case of Tuscon, where Brad Landcaster lives, it is the upper Sonoran desert. You go look at the wildlands, and the trees do fine. There are plenty of water to support the life that is there.

There are lots of ways to work with that problem and Brad Landcaster pioneered them in Tuscon, including curb cuts. You use eddie basins (and other design patterns), along with native perennials. In the case of Tuscon, those would be the native trees of Sonoran -- palo verde, mesquite, cholla, prickly pear, etc.

The curb cuts he pioneered inspired municipal laws, and Tuscon started implementing those and their own basins.

The mesa that Tuson sits on top of used to have an aquifer. That's been depleted and the city has been pumping water uphill. It does not have to be this way.

citrin_ru• 2 years ago

Drip irrigation and trees adapted to dry climate (eucalyptus?) should not increase region water use significantly.

bamboozled2• 2 years ago

There was some research posted on here a while back which suggests trees can someone encourage rain.

browningstreet• 2 years ago

Phoenix uses twice as much water as NYC with half the population.

https://www.youtube.com/watch?v=AjQuZfkU1jI

the_snooze• 2 years ago

Where do you put the trees when 1) many cities require a certain amount of parking for buildings and 2) surface parking lots are the cheapest form of parking? Cities lack trees because the requirements and incentives directly lead to paving the whole place over.

masklinn• 2 years ago

There's plenty of measures e.g. buildings close together so they can shade passages and funnel wind, literally look at middle eastern cities and you'll see it.

UniverseHacker• 2 years ago

Most of the US Southwest is naturally desert. There are only a few kinds of trees- such as the native palm that can live in these harsh conditions, and they naturally would only occur in arroyos or places where water accumulates and wind speeds are lower during storms. The soil is also just sand, and cannot support a large tree. The Los Angeles area is filled with non-native trees that are planted in sand and watered at great expense, but they fall and destroy houses and cars everytime it gets windy.

hosh12• 2 years ago

Brad Landcaster lives in Tuscon and has successfully been able to implement the rainwater harvesting methods to provide substantial shade in his neighborhood. It's not just planting trees, but changing the conditions to support a forest ecosystem.

Water retention has a lot to do with whether water gets absorbed into the ground, and the best way to do this is provide organic matter.

Here is an example, this one from Andrew Millison talking about how the central canal project of Arizona accidentally created a condition that naturally supports a forest along the canal structure. It isn't because the canal leaked, but because the canal forms a berm structure, which then accumulated enough organics to retain the monsoon rains, that then jumpstarted the succession to a forest:

https://www.youtube.com/watch?v=jf8usAesJvo

hi-v-rocknroll2• 2 years ago

Property value is typically proportional to tree density.

The US should go on a federally-subsidized, concrete-busting, native tree-planting bonanza.

Also, it should be possible to identify structures with insufficient trees by satellite to offer property owners a suggestion and a partial subsidy.

thisisauserid• 2 years ago

Those Japanese Air conditioned suits are starting to sound practical.

azinman2• 2 years ago

link?

jedberg4• 2 years ago

One law that passed after the 1994 earthquake in LA was that not only did new construction and remodels have to have all the latest earthquake safety features, but any house sold did too. You couldn't sell a house without doing the earthquake retrofit.

They should pass a similar law with some environmental requirements. The same ones that they are requiring on new construction and retrofits should also be required on sale. That would at least help.

Marsymars• 2 years ago

Maybe, but I think the minimum code standards are in general too low.

e.g. I bought a house 2 years ago where they'd replaced all the windows with double pane windows prior to selling. I'd have happily paid the marginal difference to get top-end windows, but now that I've got all new code-compliant windows, it doesn't make sense for me to upgrade them again for at least another decade.

fckgw• 2 years ago

They are passing those laws. As of 2020 all new construction homes sold in California must have a solar system installed. Also in many parts there's strict requirements on what type of landscaping they can have (no grass, only specific plants and drip irrigation allowed).

ordinaryradical• 2 years ago

I find this article extremely ironic and one-dimensional because LA is currently having a record setting year for cold.

As someone convinced by the science of climate change, I’m now increasingly skeptical of how the media portrays its nuance and uncerainty, particularly at the localized and regional level.

It would not surprise me at this point to find out in years’ time that a place like LA cools dramatically because of second and third order effects on precipitation that were not accurately accounted for while the planet overall still warms.

And I think that’s what makes the kind of prescriptivism of this article a bit nauseating.

I’m down to prevent the poor and elderly from dying of heatstroke but I question the rhetoric of this article in the way it is argued.

brisketbbq2• 2 years ago

I’m down to prevent the poor and elderly from dying of heatstroke

And i also assume from freezing to death?

First hand experience tells me that living outside in a large metro city during the summer was easier than trying to stay warm in the same city during the really cold nights.

I'm not saying it was _enjoyable_ during the summer, but I didn't have the concern of hypothermia during those really cold early mornings.

hprotagonist• 2 years ago

https://reasonstobecheerful.world/green-corridors-medellin-c....

plant vegetation.

greekanalyst• 2 years ago

This is a big problem we are facing in Greece too, especially in our concrete jungle (Athens).

Summers are not just unbearable, but becoming dangerous too.

Extreme weather events are here to stay and we need to find smart ways to handle them. We also need to prepare for a way of life that is different than what we are used to, including the social/economic ramifications of these environmental changes.

dublinben• 2 years ago

There's a lot of talk about painting pavement white, but no mention of ripping it out and replacing cars with other forms of transportation. Internal combustion engine vehicles themselves turn 100% of the energy from gasoline into heat, localized to the roads they are driving on. This pumps billions of BTUs of heat directly into a city on a daily basis.[0] We could start cooling these cities down by not unnecessarily heating them up in the first place.

[0] https://www.treehugger.com/cars-add-heat-to-cities-ban-them-...

resource_waste2• 2 years ago

The rich move to the city, the poor are squeezed out. The poor take long dreaded commutes that make them pay premiums for early/late daycare times and the long commute makes it difficult to find time to look for new jobs.

I make tons of money, I'd do great in your fantastic city. I stopped caring about the lower class last year. Your proposal is fine to me.

Just don't do a bunch of terrible bandaid things that mess up the economy in 20 years because you created a socioeconomic divide.

threatofrain• 2 years ago

Because public transportation would be the enemy of the poor?

lifeisgood99• 2 years ago

All our energy usage turns to heat. Best to stay immobile.

anamexis3• 2 years ago

Is there any evidence that the heat from cars directly contributes meaningfully to temperature in cities? I’m genuinely curious (but skeptical).

Edit: Some back of the envelope math:

Article says cars add 1.2 * 10^6 BTU of heat per day to Manhattan.

Some rough math on my part suggests that Manhattan gets about 5.6 * 10^11 BTU of heat per day from the sun, 5 orders of magnitude more. The heat directly generated by cars is a rounding error.

atomicnumber3• 2 years ago

I always think it's kind of fun when we're reminded that the sun is literally a huge fusion explosion constantly going off in the sky. Using science to further appreciate the beauty of nature strikes me as very human.

coldbrewed• 2 years ago

The heat from vehicles isn't distributed spatially across rooftops/walls/trees where the heat might be dispersed; instead the heat from vehicles is concentrated and radiated adjacent to sidewalks (impacting pedestrians) and asphalt (which is effective at storing and re-radiating heat). Nor is it dispersed evenly throughout the day; congestion during rush hour will cause a spike of heat during the hottest part of the day with greater numbers of pedestrians experiencing that heat. Idling vehicles are also running air conditioning, and all of those idling/air conditioned vehicles will be creating an ambient atmosphere where their AC systems will have to run harder to create the same level of cooling.

As you note solar heating likely dominates the overall heating of the city but I would fully expect that idling vehicles contributes meaningfully to the pedestrian and driver perceptions of heat.

milkytron2• 2 years ago

Not sure how much heat is directly contributed by cars. But regarding the original comment, having dirt or vegetation will be less heat absorbing than even white or gray asphalt. Also it helps with runoff amongst other things.

Even if cars directly aren't contributing all that much, the amount of empty parking spaces likely make their direct surroundings less hospitable than whatever the natural vegetation would contribute.

TomK323• 2 years ago

Do cars cease to exist when they are not driven? No. They sit in a parking space, most likely in the open air where they take away space for trees. Cars is why cities heat up. Put them into expensive parking houses or underground parking to have more surface space for trees.

happiness_idx• 2 years ago

While the raw numbers might suggest that the heat from cars is negligible compared to solar radiation, that overlooks the Urban Heat Island (UHI) effect and the synergistic feedback loops that make urban areas hotter. The UHI effect shows that cities are warmer than their rural surroundings because of concentrated heat sources like cars, buildings, and human activities. This local heat really impacts urban microclimates.

Plus, the heat from cars creates feedback loops. More heat means more use of air conditioning, which releases even more heat exhaust, making the area even hotter. This cycle just keeps adding to the overall heat load in the city. So, even if the direct heat from cars seems minor on its own, it actually plays a significant role in making urban areas warmer.

TheOtherHobbes• 2 years ago

If Manhattan is getting 5.6 * 10^11 BTU of free heat energy every day, there isn't much of a reason to import more from outside.

You could lose 4 orders of magnitude to inefficiency and still have plenty to run your cars.

AnimalMuppet2• 2 years ago

Almost nowhere in the American west has high enough population density to make public transportation very practical.

Sure, you could say "don't live like that". But in practice, that's saying to tear down and rebuild an absolutely massive amount of infrastructure.

On the other hand, if it gets too much hotter, a lot of people might leave, and the rebuilding project would get smaller...

wcarron• 2 years ago

Nonsense. There are multiple clear corridors that public transportation makes perfect sense for. A high-speed rail line from Fort Collins down south through Denver, to Colorado Springs, and potentially as far south as El Paso, seems obvious.

The Utah North-South corridor, as well. A line going from LA-LV-St.George-SLC area also makes enough sense. Not to mention a line connecting Tucson-Phx-Prescott-Las Vegas (potentially going to Reno as well). A Seattle-Portland train makes sense. A whole PCH line makes sense.

KorematsuFredt2• 2 years ago

Meh. Why should we reduce our quality of life ? We can always use AC in cars and and at home.

tzs2• 2 years ago

Internal combustion engine vehicles themselves turn 100% of the energy from gasoline into heat, localized to the roads they are driving on.

Let's consider a thought experiment.

We have an ICE car at the bottom of a hill. The car has a trailer attached and there is a weight on the trailer. The mass of the trailer and the weight combined is 500 kg.

The car is started, drives to the top of the hill which is an elevation gain of 100 m, drops off the trailer and weight, and drives back down to the bottom of the hill and is shut off.

The trailer and weight has gained 9.8 m/s^2 x 500 kg x 100 m = 490 000 J of gravitational potential energy, which is not heat.

If all of the energy from the car's gasoline became heat where did that 490 000 J of non-heat energy that the car gave the trailer and weight come from?

jeff_tyrrill• 2 years ago

100% of the energy becomes heat eventually. For a typical trip, this happens by the trip conclusion. (And also each time the car pauses, such as a stoplight.)

For the trailer-on-hill example, it concludes when the trailer (eventually) is towed or rolls down the hill and comes to a rest from friction.

The weighted trailer is being used like a battery and modifies the situation in the same way as if it were a hybrid car (non-plug-in battery that recharges through regenerative braking and/or directly from the ICE).

hi-v-rocknroll2• 2 years ago

That would be sacrilegious to the American identity of requiring driving to do anything.

sparker72678• 2 years ago

Have you ever been to the American West? It's nearly all suburban. You would literally have to raze what's there and start over if you wanted to be able to efficiently transport people with public transport.

brisketbbq2• 2 years ago

How much heat to jets generate?

andrewmcwatters2• 2 years ago

Why would anyone willing trade 2 12 minute drives to and from somewhere, anytime you want, immediately air conditioned, in the privacy and comfort of your own vehicle, with 2 32 minute dirty bus commutes that you have to plan in advance, walk to in the heat, and ride with other people-some of which are homeless.

What a stupid idea.

eddd-ddde2• 2 years ago

The stupid idea is believing public transit always implies longer and worse.

In most of the world where residential areas don't need highway-sized roads and you don't need 2 acres of parking lots for a grocery store, you can just walk for most activities.

Destinations are closed enough to your house that you can walk to the park or the bar. For activities that require hauling such as your groceries bikes tend to be enough. And for the people that do require a vehicle such as a work truck, there's so much less traffic on the road that it actually benefits them as well.

The issue is the US is stuck in a local minimum that is way worse than what's possible. They need cars because they build for cars because they need cars.

In reality you could _not_ need cars, because you don't build for cars, because you don't need cars.

sandworm101• 2 years ago

All this talk about re-zoning, increasing green spaces and limiting sprawl is not helpful. Imho such long-term planning considerations are just a means of delaying action. Cities need things that can be implemented and show results in years, not decades. We must adapt the cities largely as they stand today. Quick solutions are things like painting surfaces white, insulating buildings and connecting spaces via enclosed walkways to minimize loss of AC air. Other options can be more regulatory, such as allowing people to install shades over windows irrespective of local zoning rules.

vl• 2 years ago

This article talks a lot about “cool roof” but doesn’t actually tell what it is.

A "cool roof" is a roofing system designed to reflect more sunlight and absorb less heat than a standard roof. Cool roofs are typically made of materials or coatings that have high solar reflectance (the ability to reflect visible, infrared, and ultraviolet wavelengths of sunlight) and high thermal emittance (the ability to radiate absorbed or non-reflected solar energy).

It makes me wonder what is a good roof design for more northern areas - i.e. in Seattle you want “cool roof” in the summer and “hot roof” in the winter.

HeyLaughingBoy3• 2 years ago

Nope. You'd just want enough insulation that it didn't make a difference.

8f2ab37a-ed6c• 2 years ago

Come to SF, we're freezing most of the year here.

gmuslera• 2 years ago

There is a bigger problem going on that is still not thoroughly addressed. Heat domes, heavy rain floods, strong winds and other extreme weather effects are becoming more disruptive and frequent, and mitigating just one of the today symptoms without addressing the core problem may be pretty shortsighted.

The American West is figuring out how to keep cool

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