Tuesday, March 02, 2010

High-density development: more greenhouse gases than the suburbs

Resisting Dickensian Gloom
15 February 2010
Tony Recsei

High-density development in Australia is causing more greenhouse gases than the suburbs, argues Dr. Tony Recsei of the group Save Our Suburbs, in this rebuttal of a blog post by Michael Dudley.

There has been a tremendous response to my introduction to the Demographia Survey. Many have asked me to expand upon the arguments and provide documentation (such as Michael Dudley in this space: http://www.planetizen.com/node/42679), which was not possible in a preface. This I am pleased to do.

Greenhouse gas emissions
Advocates of high-density policies (often termed "Smart Growth" but also under other descriptions and euphemisms such as "urban consolidation", "compact development", "growth management" and "urban renewal") maintain these policies save energy and reduce greenhouse gas emissions.

A comprehensive study of per capita emissions in Australia based on household consumption of all products and services appears in the Australian Conservation Foundation's Consumption Atlas. Unexpectedly, this analysis shows that greenhouse gas emissions of those living in high-density areas are greater than for those living in low-density areas. An analysis of the data (1) shows that the average carbon dioxide equivalent emission of the high-density core areas of Australian cities is 27.9 tonnes per person whereas that for the low-density outer areas is 17.5 tonnes per person. As mentioned in the Demographia Survey introduction, food and goods purchased account for most of the emissions and this amounts to more for wealthier inner-city dwellers.

Surprisingly, transport emissions amount to very little (only 10.5%), household electricity and heating fuel being about twice as much at 20.0%. (2) It should also be noted that the emissions from household dwelling construction and renovations at 11.8% are greater than emissions for transport. It is clear that transport, so heavily emphasized by Smart Growth advocates, is responsible for only a small fraction of household emissions.

Interestingly, using regression analysis to attempt to isolate variables influencing household emissions, the paper on which the data is based (3) finds that density, as an isolated variable, has practically no effect on total energy requirements. The paper also finds that density has little effect on the per person energy requirement for mobility and automotive fuel consumption.

Another study which solely measures direct household energy consumption (4) (thus excluding the effect of purchases) found that annual greenhouse emissions from this source in high-rise equated to 5.4 tonnes CO2 per person per year whereas that for detached housing was only 2.9 tonnes. So even when excluding purchases associated with wealth, high-rise still comes out worst.

Yet another study, also not incorporating factors directly associated with wealth (5) finds that the total of transport, building operational and building embodied annual greenhouse gas emissions per person for city apartments is 10 tonnes whereas that for outer suburban dwellers is 7.3 tonnes---once again more for apartments.

The explanation for these findings probably partly arises from lower occupancy rates in high-rise compared to single-residential (as revealed in the above-mentioned studies) and the use of elevators, clothes dryers, air-conditioners and common lighted areas such as parking garages and foyers. Most studies do not include this latter important element, simply because they are based upon consumer bills which do not include common consumption. In addition there is the greater energy per resident required to construct high-rise.

Looking towards the future, if we are to reduce our urban energy and water footprint by individually collecting localised solar energy and rainwater it appears reasonable that this will only be practical for dwellings that have a large roof area per inhabitant. That means low density.

In summary, in the Australian situation there is no environmental emission evidence that justifies forcing people to live in apartments---if anything the reverse seems to be the case.

Not only does transport comprise only a minor portion of household emissions, the energy difference between the use of public and private transport modes is surprising small. The Sydney City Rail website states "greenhouse gas emissions per passenger kilometre for rail transport is up to five times less than that of car transport" (my emphasis).

However one cannot assume optimal conditions to always prevail such as full carriages. Such theoretical figures are just that---theoretical. Theoretical figures for automobiles would also be much more favourable if one assumes for example full occupancy of seats.

In fact the actual greenhouse gas emissions per passenger kilometre for the Sydney rail network, transporting around 500,000 passengers each day, is 105 grams. (6) The figure for automobiles in Australia, assuming an average seat occupancy of 1.3, averages 155 grams and is much less for modern fuel-efficient vehicles that emit a mere 70 grams. It needs to also be considered that direct point to point travel distances by personal transport are frequently less than that for equivalent public transport journeys so further reducing the energy difference.

Our research shows that high-density developments hardly reduce per person travel intensity at all. Dudley dismisses a Melbourne study (7) I mentioned that shows that people who moved into newly converted dense areas did not use public transport to any greater extent, and there was little or no change in their percentage of car use. He claims this is due to Melbourne being "a sprawling city". However the overall density of Melbourne is not relevant here as, in addition to being well served by public transport, the converted areas are located very close to the central business district. It sometimes seems that the last refuge of Smart Growth advocates is to declare whatever they don't like as sprawl. Indeed, it could be argued that there are no cities in the developed world that do not sprawl.

Developers recognise that units without parking are not saleable. In Melbourne medium density housing projects located near commercial or transit centres invariably include one or two parking places per dwelling. (8) The initial developers of a 5.7ha site near Sydney Central Station abandoned their proposed development of the huge multi-unit project mainly because authorities insisted that a maximum limit of 60 per cent of the units could be allocated parking. (9) This abandonment was in spite of the fact that the site could not be in a better location for public transport, being adjacent to the central railway station and major bus routes that radiate out from the locality.

The reality is that, for many journeys undertaken (including travelling to locations outside the city centre, attending childrens' sport and recreational activities, transporting pets and visiting friends), public transport is unsuitable or even forbidden as with bulky goods or pets, as well as being too inconvenient and time-consuming to be of practical benefit...
The rest of the article at http://www.planetizen.com/node/42927



At 6:59 PM, Anonymous Anonymous said...

A fascinating article. I forwarded it to some colleagues who are convinced that suburban living is pure, unadulterated evil. It could be that they are 100% wrong about that.

At 8:36 PM, Blogger Rob Anderson said...

Yes, they are wrong about the suburbs. Their belief is probably based on the anti-car bias that's now fashionable, even though motor vehicles are becoming much more energy efficient. I lived in the suburbs for a while 30 years ago, and yes you needed a car, but the upside is that you have a big house with a backyard and a front yard and of course a garage. Any family with children can benefit from that kind of space. Most burbs are served by a bus system, with shopping centers nearby. What's the real problem? That farm land and open space is lost, which can be a problem, of course, depending where the development is. But for the suburbs that are already built out, the antagonism is sheer prejudice.

Note that the SF Planning Dept. shares this prejudice, which expresses itself here as the Transit Corridors theory, positing that almost unlimited development can occur anywhere near a major traffic artery. 40-story highrises at Market and Van Ness! (The Market and Octavia Plan) 450 new housing units on the old UC Extension property on lower Haight! So-called smart growthers seem to forget that there are density limits for good reason---traffic congestion, in particular. Of course the whole smart growth, high-density idea is enamored with the bicycle as a transportation "mode," as if most people would ever want to ride a bike in a major American city, except in a place like Golden Gate Park. And our transit system, which is already crowded, is making huge cuts in service for economic reasons. Nevertheless, that's the official doctrine in SF, along with a contempt for the suburbs. Every time the Bay Guardian mentions the Chronicle's C.W. Nevius, they have to tell us that he lives in the East Bay, as if that somehow invalidates his opinions about San Francisco.

At 10:54 AM, Anonymous Anonymous said...

C.W. Nevius undoubtedly lives in the east bay, along with most of the other Chronicle writers and staffers, because the newspaper business doesn't pay well enough to afford him the opportunity to live comfortably in the City. Rather sad, since I believe that Nevius provides a huge and invaluable service to all of SF's residents on nearly a daily basis.

At 12:48 PM, Blogger murphstahoe said...

Melbourne is a poor example, it's a notoriously poorly planned city. Note that Austrailia is one of the top per capita greenhouse gas emitting countries. This isn't because they are moving towards more dense development.

Just like San Francisco is not a European city, San Francisco is not an Austrailian city.

At 12:48 PM, Blogger murphstahoe said...

@anonymous - Why don't you email Nevius and ask him why he lives in the burbs, instead of speculating?

At 8:44 PM, Blogger Rob Anderson said...

I know why he lives in the suburbs: the same reason I lived in the suburbs in the 1970s---it was a great place to live: big house, front yard, back yard, a garage for the car, a shopping mall minutes away, Highway 101 an exit away. California living! I've also lived up in canyons and in city downtowns. It's all good in California uber alles.

At 9:27 PM, Anonymous Philip said...

Oh Dear,
Rob has found himself a soul-mate.

Such a pity the intelectually challenged failed to spend 5 minutes reading the ACF's main findings report. They would have quickly found the following explanation for inner suburbs having higher environmental impact than those more distant from central business districts:

Yet despite the lower environmental impacts associated with less car use, inner city households outstrip the rest of Australia in every other category of consumption. Even in the area of housing, the opportunities for relatively efficient, compact living appear to be overwhelmed by the energy and water demands of modern urban living, such as air conditioning, spa baths, down lighting and luxury electronics and appliances, as well as by a higher proportion of individuals living alone or in small households.

In each state and territory, the centre of the capital city is the area with the highest environmental impacts, followed by the inner suburban areas. Rural and regional areas tend to have noticeably lower levels of

These trends in are closely correlated with wealth. Higher incomes in the inner cities are associated with higher levels of consumption across the board.

So consumption patterns of the wealthy is what is significant, and the wealthy tend to position themselves close to the cities.

What I find really interesting in this finding is that education and behavioural change efforts to reduce environmental impacts need to focus of the wealthy rather than the poor.

As for Rob's car fantasy. Well you'll just have to look elsewhere for some valid support. The private motor vehicle continues to be the single greatest drain on community economic health and quality of life.

And of course greenhouse gas emmissions are significant. The Figure 1 chart of the report shows that petroleum consuption for transport produces about 5 times the GHG emissions of public transport and air transport combined - or about 10 times the amount produced by public transport alone.

With transportation contributing more that 10% to the total GHG pie it looks like some pretty useful benefits can be made through non-automobile transit options.

Of course their are huge gains to be made by targeting the consuption patterns in other segments, but that's hardly a reason to forgive the sins of Rob Anderson's and Tony Recsei's auto-centric holy grail.


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