I'm not sure I understand what it means to measure the "economic value of a tree". Yes, trees provide shade and reduce pollution, but does that really mean one can meaningfully attach a dollar value to a tree?
There are two statements that I think are meaningful: "this tree costs $X to plant and maintain", and "This tree provides benefits that would otherwise cost $X". But if you want to make the latter statement, are you really sure you've captured all the benefits? Including aesthetic ones? Because I'm not really convinced that's possible.
1. Has high reflectance in the infrared, so they reflect sunlight back to the sky before it is converted to heat. Built surfaces would absorb this radiation and heat up.
2. Reduce heat also by evaporating water.
3. Reduce ground level heat by providing shadow.
4. Remove pollution from air, such as sulfur oxide (SO2), nitrogen oxides (NOx), ozone (O3) and fine particles.
But yes, converting these to money is very indirect and involves a lot estimation.
The contribution of trees and albedo in general to climate change is huge. But I doubt that urban trees, specifically, contribute a significant effect. They do greatly contribute to avoiding the also-problematic urban heat-island effect, though.
It is tough to capture complete benefits and express it in a dollar amount, especially because it is already tough enough to measure the economic value of products that haven't yet competed in the marketplace.
The US Forest Service created algorithms to calculate ecological value based on rainwater each tree retains, the electricity conserved, and reduction of air pollution - that calculation just happens to be expressed in dollars. How they make that transition from ecological value to economic value is a mystery to me, but it is just something to keep in mind as you look over this. It is moreso a measure of ecological impact, not economic (though, of course, they are connected).
Natural Resource Economics is a whole field largely devoted to determining the market value of natural resources (trees, rivers, clean air, all sorts of stuff). It's messy work and difficult for reasons that others have pointed out. But it's certainly a real thing, and incredibly useful for policy-making, where being able to speak in dollar-amounts is crucial.
I take economic value to mean tradable/purchasable by another party. I'm basing that definition on the generation and sale of carbon credits in voluntary and regulatory carbon markets and the value power supply companies place on planting trees that reduce power usage (demand side management) like http://www.swenergy.org/Data/Sites/1/media/documents/news/AP...
> I take economic value to mean tradable/purchasable by another party.
Improving public health and reducing e.g. lung cancer can have value for the national economy, even if individual people do not perceive tradable value in things like buying a home on a street with less polluted air, or quitting smoking.
I guess I'm trying to differentiate hard values from soft. Hard values typically show a more direct path between the product and the action making that product. Like carbon markets that directly influence the planting of trees. There's a chain of custody between those two items that we can (read: should be able to) track.
Every value is a soft value. Everything has some usefulness, and we guess at the level of usefulness. You might think that something like an auction is good for defining hard value, but the winners curse [1] shows auctions are just good at finding people with the biggest error in their estimation. A food is another nice example. Might not be interested at all right now, but wait 24 hours without eating, and i'll be all over that meal.
Value is a slippery concept, and i think i'm willing to go out on a limb and say all value is subjective.
FTA: All these are formulated according to figures from U.S. Forest Service that estimate the total ecological benefits a tree gives in dollars. In the case of the tree in the image below, this one has a benefit for its population that amounts to slightly more than $500 USD each year.
You can't expect to get in-depth, exhaustive explanations of complex concepts in a short article, but you should looks the primary sources cited therein and critique those if you feel they fall short.
There was an article I read not too long ago that showed the areas in NYC with more trees and greenery also command higher rents.
Also on a completely anecdotal level I feel more "at ease" and less anxious when I'm in parts of cities that have a lot of greenery, especially compared to areas that are barren and nearly all concrete/brick/whatever.
I imagine I can't be the only one who feels that way.
It does fit with the other research that just seeing trees makes people subconsciously feel better.
If the affluent find it easier to keep trees that must be because they exert power to do so, which implies they want them for some reason. Same reasons they would pay more to be around them in the first place? The affluent would find it much easier to get rid of trees, even if protected by regulation, and the land value the trees take up is worth more.
I think the causation implied by this correlation is implied pretty strongly.
As you point out, it's usually fairly straightforward to calculate the costs attached to a given tree.
When you say you're not convinced that it's possible to be really sure you've captured all of the benefits, do you mean captured their exact value? Or a hard upper bound of such? Or a soft upper bound with a given confidence interval? Or even just enumerated all of the benefits?
I think calculating an upper bound with confidence interval for the value of a tree in a city would be a really interesting exercise. To do it properly you'd have to account for everything from tangible benefits (shade, reduced CO2) to vague generalities such as residents who "feel happier living in a city with lots of trees". I think it'd be possible, but definitely not trivial.
Short of using two similar cities and varying the tree density in one while making the other a control group, I'm not really sure. I was thinking of the number more as a way to assign value than discover it. Good question though!
In LA the economic value of a tree is overall negative - as the fast growing trees planted long ago have become too large and destroyed miles of sidewalks
"$1.4 billion plan to repair a backlog of broken sidewalks that will allow the city to turn over the responsibility of future upkeep to property owners.
City officials plan to spend the funds, which will average at least $30 million a year over the next three decades"
I just found out that boomregister.nl actually has even more data. It has literaly almost every tree in the country. Even tree's in forests and private tree's
As a kid coming from semi-rural area going to Uni, for months I'd trek from RMIT to the closest gardens to eat lunch under a canopy of trees at the Exhibition gardens. [0]
Melbourne's northern clime trees and some native vegetation is at risk of premature death. [1] Something like 20% or 375 different species. Lot of planning going into inner-city deforestation.
That's equivalent to about 10.8m. Apparently, there's a giant sequoia that's [EDIT: at max 11.1m], so it's not unfathomable but likely an error as you noted.
Just to clarify, it's not all of NYC trees. The map doesn't include trees in parks or on private land. It is only sidewalk trees. Still a wonderful project.
Indianapolis has a group called Keep Indianapolis Beautiful (KIB) that works to beautify the city and help decrease long term maintenance costs to the city. To that end, every year they plant thousands of trees, often removing entire plots of land from the maintenance rotation because trees don't require mowing. They have a database that tracks source nurseries, species, locations, etcetera that I'm sure would be a delight to dig through.
What a fantastic site this and the others people have posted on here are. Making this kind of information available to people is a great way to change their opinion of something that otherwise they probably think doesn't do anything for them, or that has a cost, not a benefit to the local economy and environment, and is the kind of information we need to give our kids access to so it becomes de rigeur to understand how important trees are. With all the bad news in the world at the moment, this has been a ray of sunshine, thanks.
Try reloading the page? But, yeah, the social media hooks on this adver^H^H^H^Hsite are extremely aggressive and annoying. It starts with popup, then if you close that it opens a sidebar, then if you ignore that opens a footer. All demanding that you like archdaily on Facebook.
San Francisco, CA - I helped develop a super basic Android app called Treedat, we didn't publish on the Play Store since it was just to play around with the SF dataset and we were just curious what kind of species we were looking at when we're walking around SF: bit.ly/treedat
It's anyway kind of pointless to jam such data into OSM. Most rendering tools are happy to use multiple data sources, so someone interested in such specialized information can just get it from New York City.
That doesn't mean that it absolutely shouldn't be added to OSM, but there should be some clear motivations and benefits, not just helping (hypothetical) lazy people (that might be interested in the data) avoid a JOIN (which is hyperbole, for this data you don't even have to match anything up, just use it together with a base map).
Well, but how many joins would you need to show all those data in multiple countries?
There are a lot of trees added to OSM in European countries for example, not everyone needs to know that e.g. Berlin has tree data in this DB and Frankfurt in another one.
That's what I meant by hypothetical though. How many people are scrambling to build global tree viewers that would only include the sparse data you would get by importing all the publicly available data sets?
The interest in such data is going to tend to be local or be forced to take into account the nature of the data collection (and thus benefit from directly accessing the curated source data). An example of the latter would be an academic analysis; to pull data from OSM, it would need to start by determining geographic areas with good coverage, or the results would be utterly meaningless.
People play blame-the-ODBL, but there's not really any epically strong arguments against adjusting the public records laws to be a little more flexible.
Is there a way to search ones own comments? I was in a discussion about the yearly price of urban trees a while back on HN, and I thought the numbers would be relevant to this story, but I can't find an easy way to dig up the post.
Mapping trees has many legitimate use cases (fighting invasive species that kill the trees, mapping potential hazards from falling trees or where you may need to respond most after a storm, managing trimming trees, estimating runoff and infiltration etc).
Deriving additional value from that data is hardly a case of trying to waste money.
What's notable about this is not that they're mapping the trees - that was going to happen. What's notable about this is the openness, the volunteer effort, and possibly the quality of the data and relatively low cost due to that volunteer effort. This may also have started out seeded with data from aerial photography - possibly with pretty good data on tree types and rough sizes which could be gathered from color data particularly if they used several seasons of data.
Mapping of trees was going to be done by whoever was responsible for maintaining them, on a smaller basis by anyone required to work around them (say for sidewalk work), and probably by multiple other organizations.
so, is there a consulting question in here somewhere... If there are X trees in NYC/SF, and each tree can stay alive if only peed on by 100 dogs per week, how many dogs are in those cities?
Do you think it's strange that cities need to map nature to prove its economic value?
I've never understood the appeal of cities (other than a quick 1-2 day visit).
Cities are more inefficient[1], have more pollution[2], have less nature[3], stink like shit[4], have less happiness[5], have more noise[6], require subways and mass transit just to get around, are more expensive[7], etc. (the list almost doesn't end).
What it says is that there is a point where further increases in density will provide less positive economic effects than negative. It does not say what that point is, nor does it say that there aren't means that can move the interesection point further up. The point where a city becomes less efficient than a rural area is also much further up the density scale, because to get there you first need the inefficiencies to outweight all the benefits, not merely rise faster than the benefits.
The paper doesn't even try to quantify which cities might have reached or exceeded the threshold where further density would be detrimental. All it does is try to establish office rents as an indicator of the efficiency of land use policies.
The paper itself also points out a lot of caveats even for their very limited goals.
There are two statements that I think are meaningful: "this tree costs $X to plant and maintain", and "This tree provides benefits that would otherwise cost $X". But if you want to make the latter statement, are you really sure you've captured all the benefits? Including aesthetic ones? Because I'm not really convinced that's possible.