IMO solving overheated cities is not just more trees but less population density. Less buildings, less concrete, less asphalt. Less generation of heat and pollution in the first place. Less is more essentially.
Smaller, denser cities are more walkable and have more room for parks.
Small, single-family buildings are incredibly energy-inefficient. Large 5-story apartment blocks are way more efficient.
I moved from Perth, Australia to Berlin, Germany - the difference is astounding. Living in Perth without a car was painful. Living in Berlin without a car is normal. The hot water heating is communal, even in some areas provided for entire city blocks, while every house in Perth has its own reverse-cycle air conditioning setup. High density living is just more efficient per person.
on our street there are countless trees that were likely planted decades ago, but a lack of care by the residents makes them mere shadows of their potential.
and for anyone interested, LA's a great example of how trees provide a return on investment (actual dollar return outside the tremendous ecological benefits). go onto google maps and look at the satellite view. people who have never been here can point out the expensive neighborhoods because they are the greener ones.
as for planting the trees without the permission of the resident responsible for that parkway, like I said in that previous comment, it doesn't do much good if the folks don't take care of them. we've also learned the hard way that doing things that seem additive to the hood are not always taken that way by neighbors and can cause conflict. been on the end of that a couple of times already. that said, maybe I'll stop talking about doing this and actually try it and see what folks say.
This is normal in many cities.
Trees can mean high status because
(a) you need excess land to have trees.
(b) old wealthy suburbs often have old trees (a massive old oak tree implies something).
(c) single dwelling houses that are near the city often have very old trees due to the age of the location, and can have high value because the location has now become central (due to city outskirt growth).
(d) maintaining trees costs time and money, as mentioned, so that also implies wealth (and status).
Aside: lawns are another status symbol - that is why so many people care about them so much! Think of a huge old English estate with manicured lawns, and why that is a strong symbol of wealth.
Edit: and I should say I love trees and I think they are really worthwhile, independent of any associated status!
Yep, check out a satellite view of Atherton, CA vs Redwood City next door. A huge contrast.
That's all I got after 5 minutes on Google maps.
My guess would be evapotranspiration, not photosynthesis.
Or maybe they do know what they are doing. Trees need trimming.
> not to contemplate consequences or consider other options.
Like?
Often urban trees are struggling, but I've seen workers still prune them heavily.
We have a lot of old trees around and the pavement around them is bulged, cracked and deformed.
https://www.npr.org/templates/story/story.php?storyId=561579... (2006)
If that type of tree is known to have extensive roots, perhaps you could use smaller tiles on the pavement nearby and let the roots find their way.
The eventual result might look unsettling to some, though[0] (I know it does to me).
I guess it does make part of the pavement inaccessible for wheelchair users… But then I believe that must be a massive old tree there.
We aren't separate from nature, killing it is killing ourself.
I'm not saying we shouldn't do this. I really like seeing plant life in cities and I think it really makes a psychological difference (I _love_ living in a city with a lot of green spaces and trees everywhere). But it is nowhere near as simple as placing a tree in the ground and cleaning the leaves.
Dude, we have rats running around, pigeons nesting and pooping, what biological contaminants?
We need to have less takeaway left on the street and garbage bins that are cleaned up on time.
And I have never heard of trees contribution negatively to "biological contaminants", whatever that means. Rather, trees contribute to a cleaner and healthier environment.
A big one regarding more trees is more maintenance, you've already pointed out how terrible maintenance can be, and lawns alone are an incredible example of just how inefficient we handle plants in the name of some arbitrary aesthetic, tons of water wasted, many hours spent trimming things to some ideal size that turns out to be terrible for the plant itself, etc.
Of course my paranoia doesn't ignore cool pavements either; the reflectivity does bring some mild worries: some skyscrapers are known to cause large amounts of concentrated reflective heat, but those are due to the more mirror-like reflective properties of glass rather than the diffusive matte grey/whites of these pavements. I also worry about visibility, could we end up having a "snow blindness" effect? Would driving be affected as the harsh unnatural dark contrast of a typical road is very easy to spot compared to...everything else. I'm ofcourse aware not all roads are this black but you can't deny bright yellows and whites of road markers on a deep black road would be easier to pick up on than on a greyish road.
This of course applies mostly to areas that are hot for a good portion of the year.
And I have the same concerns as you about the reflective pavement.
That is, constructed shade structures that provides shade without being unpredictable living things.
There are probably real problems with that approach too. What are they?
Note that buildings are also shade structures but they contribute to the heat island effect.
Tree trimming and eventually removal can cost 500-1000+$ for older trees which you eventually need to do to avoid having limbs and eventually trees fall on nearby cars. Roots damage local pavement again if you let the trees grow large enough. They also start taking up significant space requiring much wider sidewalks.
Of course you can remove them and add new trees regularly, but that’s another cost and tends to upset locals. Etc. granted his is usually in comparison to an empty sidewalk as it’s unusual to have other forms of public shade.
this is one of the reasons why i'm an advocate for street trees, and urban foliage in general (cuts down both incident and reflective radiation), and why i'm maddened when i see urban trees cut down or cut back (as been happening quite often in my urban neighborhood in LA). the tree trimmers i see doing this have no idea what they're doing, being low-paid laborers paid only to run a chainsaw/trimmer, not to contemplate consequences or consider other options. trees take decades to become effective shade, and minutes to butcher irreparably.
that's not to put down cool pavements, which are really cool (haha), but that trees can provide all the same benefits and more, which makes it the better first option, with cool pavements being reserved for where tree shading is difficult or impossible (like roadways and parking lots).