Skyscraper City Forum banner
1 - 20 of 42 Posts

·
WoyaoDaJb
Joined
·
941 Posts
Discussion Starter · #1 ·
"The science fiction nonsense that parks are 'the lung of the city.' It takes about three acres of woods to absorb as much carbon dioxide as four people exude in breathing cooking and heating. the oceans of air circulating about us, not parks, keep cities from suffocating.(los angeles, which needs lung help more than any other american city, also happens to have more open space than any other large city).
Nor is more air let into the city by a given acreage of greenery than by an equivalent acreage of strees. subtracting streets and adding their squire footage to parks or project malls is irrelevant to the quantities of fresh air a city recieves. Air knows nothing of grass fetishes and fails to pick and choose for itself in accordance with them."
------Extract from The Death and Life of Great American Cities, Jane Jacob

It seems extraordinary to me that so few in the world know about this fact and just assume that the more greenery coverage the better air quality for city-simply out of intuition. But of course, you may choose to believe this is crap and trust yourself more than Jane Jacob who holds expertise and command respect in this forum.
 

·
******
Joined
·
421 Posts
concrete forever....f**** the greenery....

never mind... a green city is still nicer than one without greenery...so if you dont do it for air quality, at least do it for the beauty and for better recreation opportunities....


btw, I dont knwo if you really read the book, but what Jane Jacob critizises was the way, the US modified their cities during the 50`s and 60`s. Greenery in american cities has a completely different tradition than e.g. in europe, as the US is far less densily populated and therfore has much more intact "green" outside the cities.

"The book is a strong critique of the urban renewal policies of the 1950s, which, she claimed, destroyed communities and created isolated, unnatural urban spaces. Jacobs advocated dense, mixed-use neighborhoods and frequently cited New York City's Greenwich Village as an example of a vibrant urban community"

That was mainly a car based development during that time, based upon huge motorways cutting through a grown urban structure destroying the humang scale.



greenwich village:






 

·
WoyaoDaJb
Joined
·
941 Posts
Discussion Starter · #3 ·
^^ Yes, yes, im reading that book right now infact and i acknowledge that that is not the central theme of the book, but an interesting little myth buster nevertheless.
 

·
I love my life
Cuyi Lastrassi
Joined
·
15,034 Posts
true, but it's it doesn't hurt to have greenery in our cities. where i live, for example, they just built 2 towers that are evironmentally self-sufficient.
 

·
Registered Melbourne
Joined
·
4,166 Posts
^^ so what myths are you busting?

I've just done a little bit of arithmetic after reading your previous posting, and according to my calculations, we have 2.5 hectares of land area or about 8 hectares of total area (land, sea, ice etc. ) each. That equates to an acre of land, or a bit more than three acres of total surface area, for those who can't cope with the Metric system, and can't do the conversion.

When I say "we" I mean humans ... so if we each need 3/4 of an acre (say 2 hectares) of park (or other green) land to replenish our lungs, etc., then we're in deep shit. Because we haven't taken any other animal life forms into account yet ... and even if you don't care about them, we might need them!

So, before you start razing the trees and concreting the parks of Christchurch, I suggest you might:

(1) check my figures (calculations), &
(2) check her sources (and her reasoning).

and if they're both hunkey-dory, then you'd better go out and kill all those sheep and cattle on the Canterbury Plains, because they're generating far too much carbon dioxide!
 

·
Journeyman
Joined
·
16,908 Posts
You can save more greenery by stopping sprawl than you can by dropping parks around your city. Sprawl deals in much larger acreages.

But parks and street trees are crucial for quality of life. Knuddel Knutsch is right about Greenwich Village. The same is true even more for lowrise cities which don't even have buildings to provide shade.

Street trees have other measurable benefits. Shading a building in the summer can greatly reduce the need for air conditioning. You can even get LEED points for it I think. AC represents an obscene amount of power usage in most of the US.
 

·
Registered
Joined
·
2,333 Posts
Carbon dioxide isnt a local environmental issue though, its a natural gas for living beings. Its the many synthetical carboncompunds created by combustion in cars etc that lower local air quality, and of course, ozone.

Interesting opinion though. Anyhow i do believe that large parkareas do have an affect, not (only) becouse they clean the air, but becouse they are simply free from traffic and therefore there is less density of all those dangerous particles overall, and som circulation of them.
 

·
In the bog.
Joined
·
7,918 Posts
As clever as Jane Jacobs was, I don't think she was a plant biologist, there aren't many things that can extract Co2 as efficiently and cheaply as trees.

Also trees can absorb dangerous gases like ozone, sulphur dioxide, and nitrous oxides. In addition a leafy street can have up 60% less particulates of soot in the air.

A lot of bad things happened to cities since the fifties, but too much greenery was not one of them. Even if the benefit to air quality is negligible, the shade trees cast, especially in parks, helps to create urban heat sinks. After all leaves absorb heat as well as light to photosynthesize. Under any tree the average temperature can 30% less than beyond it. This helps cut down on air conditioning.

Then there's the aesthetic and psychological benefits greenery plus the communal benefits of an open space.
 

·
Registered
Joined
·
7,536 Posts
Tree-lined streets alone can take in the carbon dioxide that exhaled by all animals.
 

·
WoyaoDaJb
Joined
·
941 Posts
Discussion Starter · #11 ·
Guys when did i say greenery are not desirable? I know that there are lots of other benefit with greenerys. But the title of this thread is not "the myth of greenery coverage benefit the city." Cetris parabis.
 

·
Premium Member
Joined
·
79,203 Posts
It seems extraordinary to me that so few in the world know about this fact and just assume that the more greenery coverage the better air quality for city-simply out of intuition. But of course, you may choose to believe this is crap and trust yourself more than Jane Jacob who holds expertise and command respect in this forum.


You might try dropping the condescending smugness. You only just found out this fact yourself.
That seems to be a theme in your threads.


Guys when did i say greenery are not desirable? I know that there are lots of other benefit with greenerys. But the title of this thread is not "the myth of greenery coverage benefit the city." Cetris parabis.
Perhaps you mean "Ceteris paribus". :)
 

·
Registered
Joined
·
25,151 Posts
Greenery fetish is based on [the schizophrenic] eco-ideology, not in scientific evidences for a real enviroment protection. I had noticed that long time ago already. In fact, most eco-fascist bullshit follows the same pattern, such as nuclear-phobia, global warming & cooling theories, nazi-vegetarianism, skyscraper-phobia, etc. Of course, you wont do anything positive following eco-fascist policies. You wont do anything positive rejecting the wonderful nuclear energy or rejecting skyscrapers, etc.

Ecologism, as an ideology, is the religion of the third millenium. And as such, it's a dangerous threat to human progress. Those who dare to challenge the eco-dogmas with empiric arguments will be persecuted for heresy. You have been warned :lol:
 

·
Premium Member
Joined
·
79,203 Posts
Greenery fetish is based on [the schizophrenic] eco-ideology, not in scientific evidences for a real enviroment protection. I had noticed that long time ago already. In fact, most eco-fascist bullshit follows the same pattern, such as nuclear-phobia, global warming & cooling theories, nazi-vegetarianism, skyscraper-phobia, etc. Of course, you wont do anything positive following eco-fascist policies. You wont do anything positive rejecting the wonderful nuclear energy or rejecting skyscrapers, etc.

Ecologism, as an ideology, is the religion of the third millenium. And as such, it's a dangerous threat to human progress. Those who dare to challenge the eco-dogmas with empiric arguments will be persecuted for heresy. You have been warned :lol:
Care to back up any of your statements, or do they all fall under your rather obvious politically-based opposition to "activism"? I'm very curious about your theories of "greenery fetish", and how there is no scientific evidence for a real environment protection, but rather being "eco-fascist bullshit". I'm sure Mr Bush would give you a pat on the head for being a good little boy and I suppose at the end of the day that would be plenty reward for you.
 

·
In the bog.
Joined
·
7,918 Posts
Oh yeah, you gotta watch out for those eco fascists - they're to blame for all the worst crimes of the twentieth century. Even when it was the communists I knew it was really eco fascists up to no good. :lol: :rofl:
 

·
Registered
Joined
·
2,333 Posts
Greenery fetish is based on [the schizophrenic] eco-ideology, not in scientific evidences for a real enviroment protection. I had noticed that long time ago already. In fact, most eco-fascist bullshit follows the same pattern, such as nuclear-phobia, global warming & cooling theories, nazi-vegetarianism, skyscraper-phobia, etc. Of course, you wont do anything positive following eco-fascist policies. You wont do anything positive rejecting the wonderful nuclear energy or rejecting skyscrapers, etc.

Ecologism, as an ideology, is the religion of the third millenium. And as such, it's a dangerous threat to human progress. Those who dare to challenge the eco-dogmas with empiric arguments will be persecuted for heresy. You have been warned :lol:
I agree that some parts of the eco-movement, as you call it, has gone to far and are to biased. For example supposed anthropologic global warming and the often total unqillingnes to discuss the sceptics. But being just as fanaticly against it is not very constructive is it, as you are in your post, you become exactly what you complain about but with different views. The eco movement has been important and so has activism. And it will remain so im sure especially since the democracy isnt yet optimal (its not optimally accesible for people to directly influence desicions).
 

·
Premium Member
Joined
·
79,203 Posts
Well, with all due respect to the late Jane Jacobs (by the way, there was an 's' on the end of her last name), I am not really sure that any "myth" has been exploded. Most schoolchildren who managed to stay awake in Science class are at least vaguely aware of "chlorophyll" and the fact that it is capable of channelling the energy of sunlight into chemical energy through the process of photosynthesis. I don't think this is seriously in dispute here, is it? The "oceans of air" that circulate around us most definitely benefit from this action of carbon dioxide being absorbed. Take away all the greenery on the planet, and I wonder what would happen to the "oceans of air". Or us, for that matter!
I'd say PresidentBjork's entry nicely sums it up:

As clever as Jane Jacobs was, I don't think she was a plant biologist, there aren't many things that can extract Co2 as efficiently and cheaply as trees.

Also trees can absorb dangerous gases like ozone, sulphur dioxide, and nitrous oxides. In addition a leafy street can have up 60% less particulates of soot in the air.

A lot of bad things happened to cities since the fifties, but too much greenery was not one of them. Even if the benefit to air quality is negligible, the shade trees cast, especially in parks, helps to create urban heat sinks. After all leaves absorb heat as well as light to photosynthesize. Under any tree the average temperature can 30% less than beyond it. This helps cut down on air conditioning.

Then there's the aesthetic and psychological benefits greenery plus the communal benefits of an open space.
 

·
In the bog.
Joined
·
7,918 Posts
A single mature tree can absorb carbon dioxide at a rate of 48 lbs./year and release enough oxygen back into the atmosphere to support 2 human beings.

Each person in the U.S. generates approximately 2.3 tons of CO2 each year. A healthy tree stores about 13 pounds of carbon annually -- or 2.6 tons per acre each year. An acre of trees absorbs enough CO2 over one year to equal the amount produced by driving a car 26,000 miles. An estimate of carbon emitted per vehicle mile is between 0.88 lb. CO2/mi. – 1.06 lb. CO2/mi. . Thus, a car driven 26,000 miles will emit between 22,880 lbs CO2 and 27,647 lbs. CO2. Thus, one acre of tree cover in Brooklyn can compensate for automobile fuel use equivalent to driving a car between 7,200 and 8,700 miles.

If every American family planted just one tree, the amount of CO2 in the atmosphere would be reduced by one billion lbs annually. This is almost 5% of the amount that human activity pumps into the atmosphere each year.

It seems to me that this can be interpreted two ways. First is the interpretation first put forward in this thread, that it would take a lot of acres to actually reduce CO2 emissions of the average person. Whilst true, most emissions directly within in a city come from vehicle exhausts. The huge carbon footprint produced by the average person in America a year is partially through power plant emissions and vehicles. Although both are of equal importance, the effects of vehicle exhaust are felt more in the city. Thus trees in cities don't necessarily have to deal with the entire CO2 emission per person, just those from a local source.
Secondly, as I said before, trees are the cheapest and most efficient way to reduce CO2 along with other airborne pollutants. In addition they help to create shade and parks open up urban areas to help stimulate air movement. So, although an acre seems to be a lot to mitigate the emissions of some cars, keep in mind its really not that large an area. In a large metropolitan area small chunks can really add up to make a difference.
 

·
Registered
Joined
·
2,333 Posts
A single mature tree can absorb carbon dioxide at a rate of 48 lbs./year and release enough oxygen back into the atmosphere to support 2 human beings.

Each person in the U.S. generates approximately 2.3 tons of CO2 each year. A healthy tree stores about 13 pounds of carbon annually -- or 2.6 tons per acre each year. An acre of trees absorbs enough CO2 over one year to equal the amount produced by driving a car 26,000 miles. An estimate of carbon emitted per vehicle mile is between 0.88 lb. CO2/mi. – 1.06 lb. CO2/mi. . Thus, a car driven 26,000 miles will emit between 22,880 lbs CO2 and 27,647 lbs. CO2. Thus, one acre of tree cover in Brooklyn can compensate for automobile fuel use equivalent to driving a car between 7,200 and 8,700 miles.

If every American family planted just one tree, the amount of CO2 in the atmosphere would be reduced by one billion lbs annually. This is almost 5% of the amount that human activity pumps into the atmosphere each year.

It seems to me that this can be interpreted two ways. First is the interpretation first put forward in this thread, that it would take a lot of acres to actually reduce CO2 emissions of the average person. Whilst true, most emissions directly within in a city come from vehicle exhausts. The huge carbon footprint produced by the average person in America a year is partially through power plant emissions and vehicles. Although both are of equal importance, the effects of vehicle exhaust are felt more in the city. Thus trees in cities don't necessarily have to deal with the entire CO2 emission per person, just those from a local source.
Secondly, as I said before, trees are the cheapest and most efficient way to reduce CO2 along with other airborne pollutants. In addition they help to create shade and parks open up urban areas to help stimulate air movement. So, although an acre seems to be a lot to mitigate the emissions of some cars, keep in mind its really not that large an area. In a large metropolitan area small chunks can really add up to make a difference.
CO2 is NOT a pollutant. Its a natural (greenhouse) gas required for the earth ecosystem.
 
1 - 20 of 42 Posts
Top