This time of year when you opened the gate that separated the treed interior from the parking lot you felt like the air conditioning had been turned on. We have very fond memories of the place. Its only disadvantage for me was that spring caused my allergies to go crazy.
Totally worth it.
It's actually comfortable to be outside there. Even in the summer it's almost completely shaded. I was kind of surprised how extreme it is. I know trees make it harder to work and if you're hiring people they probably can't tolerate it but since I'm doing everything myself I don't have to clear everything and wait for it to grow back.
Of course it's Vegas, I wouldn't be surprised if we decided to make the downtown completely indoors so we could just run AC in the streets too. It's not exactly the city of practicality.
I think you meant to say *on top of shade* because blocking the sun is the main effect here (the geometry makes more sense too!)
Less confusing phrase from abstract which implies that the 0.5deg evaporative cooling is almost a rounding error:
during the day, trees provide significant shade by intercepting solar radiation, reducing mean radiant temperature (up to 16 °C) during the day, trees provide significant shade by intercepting solar radiation, reducing mean radiant temperature (up to 16 °C)
The main benefit over other solutions is that properly selected trees require very little upkeep from humans, unlike anything mechanical or requiring movement. Though I imagine that is less the case in Vegas.
Only ambient sunlight needed here, but they'd have to make the panels horizontal (indeed, curtained at night like you say) somehow:
https://www.thebrighterside.news/post/mits-high-tech-hydroge...
Edit I guess the low-maintenance option might be some kind of giant variegated Madagascan succulent
So ... a shopping mall? Many cities do this already, linking various public indoor spaces by walkways/tunnels. Also those cities where the air outside is too cold. A few canadian universities link buildings with tunnels so students can avoid going outside.
Mostly the benefit is instead of having the concrete under you absorb and emit the sun, the leaves above you do.
This dramatically reduces the heat we feel at human height.
Did I read that right? 16°C seems like an enormous effect.
Seems like trees would be a small investment to effectively get "outdoor AC-ish"?
EDIT: for those of us who are more comfortable with Freedom Units, that's like going from 104°F to 75°F!
Wrt. water consumption - Mediterranean species like say olive trees are kind of optimized for low water consumption, by for example having leaves covered with wax-like stuff decreasing evaporation.
they just need to figure a way to reorient their panels to provide shade?
[0] only sunlight needed
https://www.thebrighterside.news/post/mits-high-tech-hydroge...
Re: olives, hopefully the terpenes can also help cloud formation
The funny thing is, if you build a wall or canopy to avoid the water consumption plus literally waiting a decade for a tree to get tall.. now you're probably in violation of your HOA height restrictions, etc. Desert cities need to basically drop the idea of conforming to the typical expectations of visitors and newcomers by trying to add greenery. It's better to add shade, dig underground, build wind-catchers[1], salsabils[2]. There's tons of basic things like making sure roof surfaces are more reflective, and more strategic architectural things[3] that can be done to improve things and the techniques have been used forever
[1] https://en.wikipedia.org/wiki/Windcatcher [2] https://en.wikipedia.org/wiki/Salsabil_(fountain) [3] https://en.wikipedia.org/wiki/Passive_cooling
https://solar.lowtechmagazine.com/2025/06/dressing-and-undre...
Increasing *evaporative* cooling by 0.5deg requires 3x more water, but shade alone is the *main* mechanism,it doesn't require water.
>during the day, trees provide significant shade by intercepting solar radiation, reducing mean radiant temperature (up to 16 °C)
Right where I am sitting now I have an LED strip above my desk and when I have my shirt off (right now) I can very definitely feel the radiant energy when it is on, so if it is really hot I either turn it off or switch it to green because the eye is most sensitive to green light. In fact, as I'm writing this, I just set the backlight on the 55-inch TV I use as a computer monitor down so I'd feel more comfortable.
https://www.thebrighterside.news/post/mits-high-tech-hydroge...
The limited effect is that cities are dense and can't be made as forest so trees can't do nothing for buildings taller them them.
https://www.knpr.org/show/knprs-state-of-nevada/2024-08-29/w...
For instance where I live east of the Cascades, in the dry part of Oregon, only like 10% of the water used goes to the cities.
https://www.centraloregonlandwatch.org/update/2021/5/5/droug...
Street trees are hugely beneficial and if you want to cut something (ha ha), you want to look at things like lawns or golf courses.
Trees in cities are not about reducing water usage by any significant amount. They are still lovely, though.
I found this quote in this 2016 PDF from the EPA:
https://www.epa.gov/sites/default/files/2017-02/documents/ws...
Trees were the first thing planted. Fast growing trees, placed to cast shade on the house.
After a few years, those dirt lots transformed into some very nice properties where sitting outside in the shade with the desert zephyrs rustling the leaves provide a very nice, idyllic place for conservation or reading.
I agree growing things in the desert may be inefficient, but speaking for the CO river, that problem is in California and Arizona.
https://www.snwa.com/water-resources/where-water-comes-from/...
https://www.cleanwaterteam.com/about-us/who-we-are
> [Las Vegas] used 38 billion gallons less water in 2024 than in 2002, despite a population increase of approximately 829,000 residents during that time. This represents a 55 percent decline in the community’s per capita water use since 2002.
However, large scale commercial agriculture in desert areas without significant ground water - that's a new thing, and it's a problem.
Desalination that runs off of Solar panels makes it pretty viable for places like Dubai to exist. The cheap solar energy from the Desert, makes it attractive for future data centers to be placed there. Also, Ancient Egypt had slaves. A lot of the modern middle eastern states rely on cheap labour from India and Afghanistan. And Oil money ...
(also, I don't think the Central Valley is actually a desert?)
^ the rub ^
Since the point of the trees has been discovered to be just shade and not evaporative cooling, they just need to figure a way to reorient their panels?
[0] only sunlight needed
https://www.thebrighterside.news/post/mits-high-tech-hydroge...
OK, let's go full mad world: a vast web of PV for power. Is there a handy massive water resource deep underground? If not then moisture in the air will need redeploying. Tall towers and probably gobs of power are indicated for that.
There was.
We've been sucking them dry for a century or more, everywhere they exist.
If people were really serious about living in deserts in a sustainable way, they can't expect to have decorative greenery or classic architecture. A society as advanced as ours should be able to make compromises that allow modern comforts while adapting so well to their environment that the cities would look almost alien.
The architecture has existed for centuries, maybe even millenia. Some of us already live that way.
The irony is that the key thing - large thermal mass - has now become the province of only those with lots of money, or those with no money. Everyone in the middle is stuck with silly construction options for a desert climate.
In Europe we even assigned our first "Chief Heat Officer", which makes total sense.
Air temperature is already high (e.g. 36C at my location just now), and radiant heat from sun and concrete can make the felt temperature more like 60C.
It's sad that new real-estate layouts continue to be approved, which will only be good for this type of dense concrete hell.
Las Vegas is embracing a simple climate solution: More trees (npr.org) 21 days ago | 143 comments https://news.ycombinator.com/item?id=44231151
Nights in Las Vegas Are Becoming Dangerously Hot (nytimes.com) 10 months ago | 1 comment https://news.ycombinator.com/item?id=41223831
Fuck off.
Then that vanished and another even more vapid effort appeared.
Fuck off.
If you need to piss around with this sort of nonsense, you probably shouldn't be entrusted with a website.
looks like the archivers have trouble with it too; reminds me of the behavior of a virus with all the redirects lol
edit: for those with custom filterlists via ubo:
- ||iop.org
There's also a direct PDF link https://iopscience.iop.org/article/10.1088/2752-5295/ade17d/... that also prompts for captcha (unless you arrive there via the web version)
Looping redirects on archive.XX urls often traces back to the use of Cloudflare DNS resolver .. the archive folk have some beef with Cloudflare over (?) handling privacy (?) and loop redirects on connections that arrive via that path.
It's a new captcha type for myself also. Interesting as it requires spatial reasoning and a bridge of understanding between text request and objects in images - although it falls to the usual farm of human captcha solvers.
This seems to be the offending product being used, although the captchas themselves are standard hCaptcha.
The sky is rarely cloudy and solar just blasts all day every day here.
I covered my backyard in Vegas with ground panels and now I charge my EV off of a 100% off grid solar system. The sun provides enough energy in my small yard for 2-3x my driving needs.
Do we all need to run an AI browser plugin now that auto-fills cloudflare captchas ?
What happens if you import northern US trees, the ones that produce a lot of shade, into southern states? Has this been tried?
It is also why there is very little shade in, say, Florida. Only occasional parts of the Martin Grade “scenic” highway look like a regular scene in the north.
But it is more complicated than that, of course. It's not just "how hot does it get", but also how much water is available, how windy it is, how cold it gets, and a million other environmental factors. That's why there is such a wide variety among the plants on earth.
(and yes, it has been tried. Check out the youtube channel "crime pays but botany doesn't")
Edit: And cooling only works inside buildings or cars. Part of a comfortable city is being able to go outside and have a social life outside of a casino.
If the US' alfalfa exports to Saudi Arabia went down by 10%, we would never have a municipal water shortage in the American West in the next century.
For Las Vegas, Cottonwoods are native and grow pretty quickly. Like many poplars they were used to grow shelterbelts.
We pump oil via pipelines vast distances, we can do the same with water.
We have virtually unlimited energy locked in Uranium which could power desalination plants, or heck you could power them with solar.
There’s plenty of water for the whole planet. There’s also plenty of clean energy (see nuclear and solar point earlier). But tapping these resources requires a functional government or at least a bureaucracy willing to allow companies to build.
...just not so much in May-August.
Very few municipalities are willing to deny new residents, either. It wouldn't be anywhere on my list of viable places to live, but population growth in the Las Vegas metro area has been consistently large since 1910 until recently (only 10% growth from 2010 to 2020). The municipalities should likely invest in livability and comfort where possible.