Monday, February 28, 2011

What Causes Sprawl?

Do Large Residential Subdivisions Induce Further Development? A Spatially Explicit Hazard Analysis of Land Use Change in Charlotte (Bev Wilson &Yan Song, Journal of the American Planning Association., pages 5 – 22, December 2011

Also discussed here: Sprawl Breeds Sprawl (Angie Schmitt, Streetsblog, Feb 8, 2011)

Today’s article looks objectively at what causes sprawl (development and freeway adjacent) and what discourages it (mixed use development) and recommends that environmental assessments examine these factors. The importance of curtailing sprawl and the resulting growth in commuting traffic and downtown congestion and foul air cannot be understated.

Key Quotes

“evidence of a positive association between large residential subdivision events and an increased likelihood of subsequent subdivision activity.”

“adding one large subdivision event within one-quarter mile of the parcel in the previous period was associated with a 42 percent increase in the odds of the parcel subdividing.”

“In other words, we’re much more likely to see a new subdivision cropping up near a recently built one than we are to see it where there has been no previous development”

“factors that increased the likelihood of new development, including being near the I-485 freeway, being near a rail corridor, and being near demolition activity but none of these was as influential as being near previous development.”

“the presence of mixed-use development decreases the likelihood of new subdivision, as do higher property taxes and location within a nonresidential neighborhood.

“the most important implication is that environmental review of a proposed project should include review of not just its likely site-specific effects but also those of additional development that could be induced nearby”
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Friday, February 25, 2011

The Top Sustainable Canadian Cities

The 2011 Most Sustainable Cities in Canada (Corporate Knights, Feb. 9, 2011)

Also discussed here: The Metabolic Metropolis (editorial) (Corporate Knights, Feb. 8, 2011)

And here: Expanded Results (1 page pdf, Corporate Knights, Feb. 8, 2011)

Today’s review article is important because of the characteristics and programs that the top ranking cities use to achieve sustainability as well as to reduce harmful pollution to a minimum. It also allows for a comparison of cities making allowance for size and population, so that smaller cities such as Victoria or Mississauga score higher overall than Ottawa, Calgary or Montreal. The importance of governance and empowerment (established emission targets, education, voter turnout, etc) helped to keep Toronto and Vancouver among the top cities, while Saskatoon enjoyed the cleanest air quality (in terms of particulate matter) and Montreal and Edmonton got top marks for biodiversity.

Key Quotes:

“because of their urban “metabolism,” cities require only 85 per cent of the resources necessary to double in size, and they’re more energy efficient than rural communities”

“increased worldwide migration to cities is helping curb population growth because there is no need for large families for labour”

“When villagers migrate to the city, their family size drops, on average, by at least one child per family, often below the steady population rate of 2.1 children.. Without massive rural-to-urban migration, the world’s population would be growing at a far faster pace”

“We studied 28 indicators of sustainability in five categories—ecological integrity, economic security, infrastructure and built environment, governance and empowerment, and social well-being.. Toronto, Vancouver, and Victoria won top honours in our Big, Medium, and Small city categories respectively”

“Many of the strategies for reducing environmental pollution or reducing greenhouse gas emissions more broadly come down to actions that have to be taken at some city scale, whether that’s at the metropolitan, municipal, or corporate level.”

“Edmonton stands out in the biodiversity field. They joined the international Cities Biodiversity Index in 2010 and city staff is proactively monitoring hazard trees and invasive species”

“Saint John deserves applause for its Green Thermal Utility plan, a multi-building project that would make use of renewable energy sources, such as waste energy from Irving Pulp and Paper

“Vancouver stands out for its competitive commitment to sustainability, with its Greenest City Action Team initiative aiming to transform the city into the world’s greenest city by 2020”

“Victoria topped the Small City category, and matched Vancouver for highest numbers by developing its Victoria Sustainability Framework, making sustainability a guiding principle of all city business”
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Thursday, February 24, 2011

How the Government Controlled Air Pollution at the Beijing Olympics

2008 Summer Olympics Celemony HK

Estimated Reduction in Cancer Risk due to PAH Exposures if Source Control Measures during the 2008 Beijing Olympics were Sustained (31 page pdf, Environ Health Perspect, Feb.8, 2011)

The 2008 Olympics and the significant efforts made to reduce sources of air pollution during the games offered a unique opportunity to assess the effectiveness of the control methods in terms of reduced health risk of cancer from inhaling this pollution. The article reviewed today provides several measures of the positive impact of these reductions.

Key Quotes:

“300,000 people die each year in China from heart disease and lung cancer associated with exposure to ambient air pollution, including carcinogenic polycyclic aromatic hydrocarbons (PAHs)…an average of 6.5 per million people in China are estimated to have lung cancer due to PAH inhalation exposure and populations in major Chinese cities have a higher risk of lung cancer than average for China”

“Chinese megacities, including Beijing, suffer from severe air pollution due to increasing coal combustion and motor vehicle emissions..PAH emissions from biomass and coal combustion for heating and cooking are a dominant source of indoor air pollution in China

“Emissions from the power plants, coal-fired boilers, and several heavy-polluting factories in Beijing were reduced by 30-50% during the Olympic Games”

“A key component of the source control measures during the Beijing Olympics was restriction of on-road vehicles, in addition to industrial emission controls….As a result, the traffic volume was reduced by ~32% during the source control period….However, the number of vehicles in Beijing is increasing by 13% per year, with 4 million vehicles in 2009”

“the lifetime excess inhalation cancer risk due to exposure to the 17 carcinogenic PAHs was estimated to range from 6.5 to 518 per million people for the source control period concentrations.. This corresponded to a 46% reduction in the estimated inhalation cancer risk”
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Wednesday, February 23, 2011

Health Threats from Wood Smoke Particles

Oxidative Stress, DNA Damage, and Inflammation Induced by Ambient Air and Wood Smoke Particulate Matter in Human A549 and THP-1 Cell Lines (Abstract, Chemical Research in Toxicology, Feb. 5, 2011)

Also discussed here: Air Pollutants from Fireplaces and Wood-Burning Stoves Raise Health Concerns (Science Daily, Feb. 5, 2011)

And here: Where there’s fire, there’s smoke (Pollution Free Cities, July 22, 2009)

And here: Health Risks from Burning Wood and Coal (Pollution Free Cities, Sep. 28, 2010)

Today’s journal review article is very timely for northern communities such as Ottawa or Montreal in Canada, where wood burning stoves and fireplaces are widely used. And yet as the article points out, the health impacts of the fine particulates in wood smoke are not as well reseached or recognized as the health threats from pollution from diesel trucks and buses.

Key Quotes:

“abundant scientific evidence linking inhalation of fine particles of air pollution -- so-called "particulate matter" -- from motor vehicle exhaust, coal-fired electric power plants, and certain other sources with heart disease, asthma, bronchitis and other health problems. However, relatively little information of that kind exists about the effects of wood smoke particulate matter (WSPM)”

“We assessed a wide spectrum of toxicity end points in human A549 lung epithelial and THP-1 monocytic cell lines comparing WSPM from high or low oxygen combustion and ambient PM collected in a village with many operating wood stoves and from a rural background area”

“the invisible particles inhaled into the lungs from wood smoke may have several adverse health effects”

“Airborne particles in the village and pure WSPM tended to be of the most potentially hazardous size -- small enough to be inhaled into the deepest parts of the lungs”

“WSPM contained higher levels of polycyclic aromatic hydrocarbons (PAHs), which include "probable" human carcinogens. When tested on cultures of human cells, WSPM also caused more damage to the genetic material, DNA; more inflammation; and had greater activity in turning on genes in ways linked to disease”
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Tuesday, February 22, 2011

Do Petrol Stations Pollute?

another example of what Canadians call a gasbar.Assessing the impact of petrol stations on their immediate surroundings (8 page pdf, Journal of Environmental Management, December 2010)

Also discussed here: Petrol stations pollute their immediate surroundings (Eurekalert, FECYT - Spanish Foundation for Science and Technology ,Feb. 4, 2011)

And here: Traffic, Pollution and Scales of Exposure (Pollution Free Cities, Jan 3, 2011)

Research from Spain examines vapour emissions from gas stations. It recommends a 100 m belt around these stations to reduce health impacts, in addition to the risks of roadside emissions which extend some 100-300 m from roads with heavy traffic, according to European studies.

Key Quotes:

“the ratio of the concentrations of aliphatic and aromatic hydrocarbon pollutants in the air of the petrol stations and their surroundings (basically determined by vapor emissions from unburned gasoline) differs from the ratio found in urban air, which is mainly influenced by traffic emissions”

"Some airborne organic compounds – such as benzene, which increases the risk of cancer – have been recorded at petrol stations at levels above the average levels for urban areas where traffic is the primary source of emission"

"In the three cases studied we obtained maximum distances of influence of close to 100 metres, although the average distance over which this contamination has an effect is around 50 metres"

“the distances depend on the number of petrol pumps, the amount of fuel drawn from them, traffic intensity, the structure of the surroundings, and weather conditions”

"the more contaminated the zone surrounding the petrol station as a result of other causes (traffic), the lower the impact of the two pollutants at the service station"

“The procedure should help local authorities in terms of land management, so that a “belt” can be established around petrol stations where housing or vulnerable populations and activities such as those in schools, hospitals and community centers should be restricted”
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Sunday, February 20, 2011

PlaNYC-Air: New York City's 2030 air initiatives


PlaNYC Air
(40 MB pdf, New York City, 2007)

"Despite decades of improvement, New York City still fails to meet Federal air quality standards—and we have no way of measuring the air quality in individual neighborhoods.That’s why we will create a comprehensive program to reduce emissions from a variety of sources within the city, including vehicles, power plants, and buildings. Natural solutions such as planting one million trees will bring us the rest of the way towards cleaner air for all New Yorkers. To track our progress and target our solutions to the areas of greatest need, we will launch the largest local air quality study in the United States.Together, these initiatives will enable every New Yorker to breathe the cleanest air of any big city in America" (Mayor Michael Bloomberg, 2006)

Retrofitting Car-Dependent Cities

New Urbanism for the Apocalypse (Fast Company, May 24, 2010)

(4 min You-Tube lecture, May 20, 2010)

Key Quotes:

Duany believes the metaphorical asteroid -- call it peak oil, climate change, the collapse of complex structures -- is on its way…America abounds with intentional communities -- golf course communities, equestrian ones, even the fly-in kind. So why not build one for locavores?”

“Agrarian urbanism.. is different from both urban agriculture (cities that are retrofitted to grow food) and agricultural urbanism (when an intentional community is built that is associated with a farm)…Agrarian urbanism is a society involved with the growing of food."

“they would have gardens instead of yards, or community gardens and window boxes if they choose to live in an apartment. Their commitment to "hand-tended agriculture" would be part of their legally binding agreement with the homeowners' association…. Instead of a strip mall in the town square, there's a "market square" comprised of green markets, restaurants, cooking schools, an agricultural university, and so on.”

“perhaps the next urbanism will be single-story buildings built on a cash (or barter?) basis, while jitneys and "bottom-up" forms of transportation will replace both cars and mass transit.”

"There's a reason we don't talk about population is because we're not going to do anything about it. There isn't going to be any protocols or policies. There will be the disasters and famines, and we don't how much social disorder will stem from that."
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Health Impacts from Residential Traffic Exposure

Residential Traffic Exposure, Pulse Pressure and C-reactive Protein: Consistency and Contrast Among Exposure Characterization Methods (45 page pdf, Environ Health Perspect, 02 February 2010)
Key Quotes:
Traffic exposure has been shown to increase cardiovascular disease (CVD) risk via systemic inflammation and elevated blood pressure
association between traffic exposure indicators as predictors of C-reactive protein (CRP) and pulse pressure in an adult U.S. Puerto Rican population
Pulse pressure was positively associated with residence 100 m of a roadway with a difference of 2.2mmHg (95% CI, 0.13 – 4.3 mmHg) for the total population and 3.8 (95% CI, 0.88 – 6.8) for those with BMI 30.
Differential personal exposure to particles, gaseous pollutants and traffic pollution have been associated with lower socioeconomic position with respect to education, minority status and income and major roadways have been routed through lower-income areas with less political and economic power
Traffic density has been identified as a significant predictor of NOx, NO2, PM2.5, the soot content of PM2.5 and volatile organic chemicals
Roadway proximity 100 m was significant for pulse pressure, whereas proximity 200 m was significant for CRP.
This study found adverse health effects were associated with residence near roadways with traffic volumes between 20,000 – 40,000 vehicles per day, suggesting risks from residential exposure at lesser roadway volumes than previously reported.

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Clogged Arteries near Highways

Ambient Air Pollution and the Progression of Atherosclerosis in Adults (10 page pdf, PLoS ONE 5(2), February 8, 2010)

Also discussed here: Study finds traffic pollution can speed hardening of arteries (Los Angeles Times Feb. 14, 2010)
Key Quotes:
Cardiovascular disease (CVD) is the most important cause of morbidity and mortality in the developed world, and atherosclerosis is the central underlying pathology…no study has investigated the impact of ambient air pollution on the progression of atherosclerosis in humans.”
“To increase the number of subjects falling into the ‘high exposure zone’ .. we also used proximity to highways (100 m) or living within 50 m of a major road as a marker of exposure. Traffic density, and in particular diesel truck density, is much lower on main roads than on highways”
“the major weakness of the study remains the limited sample size. The percent of people living very close to highways is small, in general, and was only 1.6% in our more affluent population “
“In line with other U.S.- based air pollution studies, the effects were stronger among the socioeconomically disadvantaged, a possible marker for concomitant adverse environmental exposures, poor diet, and a more stressful life‘
“Proximity to highways may be a marker for exposure to high loads of ultrafine particles and other highly redox-active pollutants. .. The larger particles (i.e. PM2.5) may result in inflammatory reactions in the small and upper airways alike, and both types of pollution may independently enhance systemic inflammation . Second, the independent effects may indicate that both exposure assessment approaches capture similar types of pollution but on different spatial scales and concentration levels; ‘proximity’ would characterize the most extreme local conditions (hot spots) while PM2.5 captures the additional contrast occurring between geographic areas”

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Road Pricing Options for Australia

Moving People: Solutions for a growing Australia- key transport issues (81 page pdf, the Australasian Railway Association, the Bus Industry Confederation and the International Association of Public Transport–UITP, April 2010)

Also discussed here: Moving People: Solutions for a growing Australia (World Streets, April 12, 2010)

Australia shares many transportation and energy issues with Canada- and other developed countries. Both countries have similar populations (23M and 32M) with close to 90% concentrated in a 20 or 30 cities. Their populations are growing older (and more obese) with changing needs for mobility. Both countries have high per capita energy consumption because of summer heat and air conditioning demands on the one hand (and winter cold and heating for Canada on the other). Also both countries have begun to examine solutions among which road pricing is a key.

Key Quotes:

“road traffic congestion cost Australia almost $10 billion nationally in 2005 [pop 22.3M est 2010]and that this cost will double by 2020: Sydney $3.5bn [pop 4.4M est 2008], Melbourne $3bn, [3.9M], Brisbane $1.2bn, [1.9M], Perth $0.9bn and [1.6M], Adelaide $0.6bn[1.2M]”

“UK research has suggested that urban congestion costs (in the UK) can be cut by over 40 per cent if congestion pricing reduces urban traffic volumes by about 4 per cent”

“52 per cent of women, 67 per cent of men and 25 per cent of children are overweight or obese in Australia ..obesity has more than doubled in the last 20 years… estimated to cost $14b annually in Australia.42 This is larger in scale than road congestion costs”

air pollution from motor vehicles accounts for more than 500 early deaths in the Sydney Region per annum and over 1,000 hospital admissions, and that the health costs of motor vehicle emissions .. between $600 million and $1.5 billion per annum”

“Governments subsidise 70–75 cents of every dollar of transport expenditure”

“A reformed transport pricing regime:

1. a user-based charge to cover carbon costs

2. a usage-based charge to cover the costs of road construction and maintenance attributable to lighter vehicles;

3. tonne kilometre charges for the additional road damage attributable to heavy vehicles;

4. a use-based charge to cover the external cost component of accident costs;

5. use-based charges to levy the more polluting vehicles for their health (air pollution) costs

6. a congestion pricing scheme to make users accountable for the congestion costs attributable to their road use, by time and location. At peak hours in the capital cities.. as high as $1/km"

“.. a vehicle kilometre charge that is levied based on the particular roads used, the traffic conditions at time of use and the vehicle emission performance and mass characteristics. New GPS technology is suited .. Dutch are leading the field in the development and implementation of such an approach to road user charging“
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Effects of Air Pollution Exposure on Blood Pressure and Vascular Function in Healthy Humans

Insights Into the Mechanisms and Mediators of the Effects of Air Pollution Exposure on Blood Pressure and Vascular Function in Healthy Humans (Abstract-Hypertension. 2009;54:659.)

Key Quotes:

"Fine particulate matter air pollution plus ozone impairs vascular function and raises diastolic blood pressure.We aimed to determine the mechanism and air pollutant responsible."

"In Toronto, diastolic blood pressure significantly increased (2.9 and 3.6 mm Hg) only during particle-containing exposures in association with particulate matter concentration and reductions in heart rate variability"

"In Ann Arbor, diastolic blood pressure significantly similarly increased during all of the exposures (2.5 to 4.0 mm Hg)"
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Exposure of Commuters to Air Pollution

Commuters’ Exposure to Particulate Matter Air Pollution is Affected by Mode of Transport, Fuel Type and Route (35 page pdf, Environ Health Perspect, 25 February 2010)
Key Quotes:
The aim of the study was to quantify differences in exposure to air pollutants in traffic compared to simultaneously measured urban background concentrations, and to examine the differences in air pollution exposure associated with commuting by car, bus and bicycle.
a significant portion (up to 30%) of air pollutants in (school) buses is due to self-pollution..Open windows during driving, idling of the bus and opening of bus doors lead to higher in-bus exposures
On average, the minute ventilation of cyclists was 2.1 times higher than that of car passengers and 2.0 times higher than that of bus passengers…Inhaled doses of all air pollutants were highest in cyclists
Exposures were higher in diesel buses than in electric buses, and higher along high-traffic bicycle routes compared to low-traffic bicycle routes
Cyclists on the high-traffic route were exposed to 40% higher levels of PNC and 35% higher levels of soot compared to the low-traffic route.
City planners should create bicycle lanes with less (preferably: no) contact with motorised traffic.

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The benefits of reducing 1 ton of air pollution

The influence of location, source, and emission type in estimates of the human health benefits of reducing a ton of air pollution (8 page pdf)

Key Quotes

"The benefit per ton ($/ton) of reducing PM2.5 varies by the location of the emission reduction, the type of source emitting the precursor, and the specific precursor controlled. This paper examines how each of these factors influences the magnitude of the $/ton estimate."

"This heterogeneity is a product of source location, meteorology, mix of pollutants emitted, and atmospheric conditions, including baseline atmospheric concentrations of pollutants."

"Three inter-related sources of heterogeneity affect the magnitude of PM2.5 $/ton estimates.

The first relates to the chemical processes that govern the formation of PM2.5 in the atmosphere....

The second source of heterogeneity relates to the characteristics of the emitting source...

The third factor that may influence the heterogeneity in PM2.5-related $/ton estimates is the size of the population exposed to PM2.5 and the susceptibility of that population to adverse health outcomes."

"It should be noted that, while NOx reductions may occasionally generate PM2.5 disbenefits in certain urban areas, because NOx is also an O3 precursor, additional NOx reductions—even in areas where PM2.5 disbenefits are possible—may produce a downwind O3 benefit."

"The PM2.5 $/ton estimates in this paper reflect three principal sources of heterogeneity:

Variability across precursors. The $/ton for certain pollutants, such as directly emitted PM2.5, is much higher than others...

Variability across sources. Certain sources may emit a common precursor, but may produce very different $/ ton estimates...

Variability across location. The $/ton for a given pollutant showed some degree of variation based on the urban area in which the pollutant was emitted."
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The Air We Breathe

The Air We Breathe is a 30 minute video produced by the Cable Public Affairs Channel(CPAC). Up to date and comprehensive look at  leading edge research in air quality and aerosol monitoring and their health impacts  at several Canadian universities including McGill, University of Toronto, York University and Simon Fraser University.

Aerosol Time-Of-Flight Mass Spectrometer (ATOFMS) used by University of Toronto at its "Southern Ontario Centre for Atmospheric Aerosol Research (SOCAAR)" - see Leading-edge air quality research centre to be based at U of T

Here's the summary of the video:

"The Air We Breathe

CPAC presents an exclusive documentary examining the deteriorating quality of air. No country or continent can escape the effects of air pollution. See what Canadian scientists and researchers have uncovered about the most basic of life's necessities.

The air we breathe is under assault. And it's a global problem. Did you know that Canadian scientists can determine that a particle of pollution found in Canada originated in Australia or China? Every day in Canada, 40 people die prematurely from illnesses related to air pollution. Canadian scientists are on the cutting-edge research to determine what's in the air we breathe and what effect it has on us. Join videographer Bill Luxton as he travels the breadth of the country examining the work of some of Canada's leading atmosphere scientists and how their findings could influence the national debate over climate change"
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Sustainable Urban Infrastructure

Sustainable Urban Infrastructure London edition – a view to 2025


- a brief (6 page)  look at the City of London's urban infrastructure  and what is needed to make it more sustainable by 2025 with ecological footprint analyses and estimated costs from the aspect of: water, air pollution, municipal waste, CO2 from buildings, industry and transportation.

The full (72 page) report can be downloaded from this link:

Sustainable Urban Infrastructure London Edition – a view to 2025 A research project sponsored by Siemens

Secondary Organic Aerosols

OnAir: Research Underdogs Fill Atmospheric Blind Spot (EPA Greenversation, Apr. 6, 2010)

Also discussed here: Carnegie Mellon Researchers Urge Regulators To Rethink Strategies for Controlling Soot Emissions (Carnegie Mellon News, Mar 1, 2007)

And here: The Missing Source of Secondary Organic Aerosols (SOAs) (Science Quick Picks, Mar. 7, 2007)
Key Quotes:
“What we actually observe in the atmosphere is a factor of 3 – 100 times more than the SOA traditional models predict,”
“new chemical processes that occur after soot and gaseous pollutants are emitted from cars and trucks, changing the chemical and physical properties of the soot particles and creating new particulate matter.”
" this chemical processing leads to more particulate matter in the air, meaning that regulators are likely underestimating how sources such as cars and trucks contribute to pollution,"
"A second important finding is that the properties of this new particulate matter are different than we previously thought and potentially more toxic”
"We're seeing that urban pollution doesn't stay contained in the cities, but impacts rural and other downwind areas, creating even more complicated issues for regulators,"
"For the longest time, particulate matter has been the least understood component of the climate system.”

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Automobile Dependence and the Future of Roads

Newman at rest
Image via Wikipedia
The future for roads in 2050 - Australian perspectives on sustainable transportation (World Streets, Apr. 23, 2010)

Also discussed here: RESILIENT CITIES - Responding to the Crash, Peak Oil and Climate Change (151 page pdf slideshow, Peter Newman, Professor of Sustainability, Curtin University, Australia)

And here: Sustainable Urban Transport - Responding to the crash.... (35 page pdf slideshow, Peter Newman, Professor of Sustainability, Curtin University, Australia)

From the father of “automobile dependence”,  Prof. Peter Newman, comes a look at what lies ahead for roads - in Australia at least, but many of his observations appear valid in similar countries such as the US and Canada. From an urban air quality viewpoint, roads and the vehicles that use them represent one of biggest if not the greatest source of pollution – as discussed in more detail in this recent post Vehicle Emissions and Climate Impacts.

Urban sprawl and pressures to accommodate it have resulted in cities whose downtowns are choked with emissions, particularly on the multi-lane roads that converge on the urban centre(s). The long-term solution seems to lie in redesigned cities that discourage car use through offering more attractive alternatives including rapid transit, cycling and walking with job locations closer to residential areas.

Key Quotes:

“we will have roads with about 50% fewer cars on them in 2050 compared to today.”

“a structural shift as public transport use has accelerated rapidly and younger people are driving the market for more urban locations where they need cars less.”

“reclaiming road space for more urban uses..with a light rail, removing cars altogether from most of the city centre road system and in sub centres.

“sub-centres will be built across the polycentric city. Cycling and walking will be the preferred choice for all local trips as parking will be so expensive and car access into all centres across the city will be much less attractive for cars”

“will have a much more extensive electric rail system and all cars will be plug-in electric”

“Cities adapt to the one-hour travel time budget no matter what infrastructure is provided.“

“in Australian cities each new block on the fringe of redevelopment:
  • Is subsidised by $85,000 in infrastructure.
  • Costs $250,000 extra in transport costs over 50 years.
  • Produces 4.4 tonnes/yr more in greenhouse gases, and health savings“
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Communicating Scientific Concepts

Greenhouse Effect
Image via Wikipedia
Do Earth and Environmental Science Textbooks Promote Middle and High School Students ' Conceptual Development about Climate Change? Textbooks ' consideration of students' misconceptions (Bulletin, American Meteorological Society, p. 889-898, Volume 91, Issue 7, July 2010)

The article reviewed today looks at how climate change concepts are described in textbooks used by high school students and teachers.  It found  a tendency to oversimplify or exaggerate many concepts, as well as to avoid the degree of inter-linkages between the various fields and forces at play.  It concludes with three recommendations to make up for these deficiencies. The complexities of climate change science seem not unlike the links between vehicle emissions, level of pollution and impact on human health that are the focus of this blog.  One aspect, in particular, is the apparent lack of communication and knowledge exchange between highway traffic engineers, air quality scientists and environmental health authorities, with the result that each of the three disciplines continue without the progress that might be expected if all were regarded as parts of the bigger problem – as well as in education of the public as addressed in this article.

Key Quotes:

“It is critical, therefore, that science textbook authors and publishers are aware of students’ common misconceptions about climate change when developing textbooks so that their works become effective tools for facilitating students’ conceptual development”

“The reviewed earth and environmental science textbooks did not adequately address students’ misconceptions about climate change, suggesting a need for revision.“

“Most of the reviewed studies reported that many held the misconception that the greenhouse effect is caused by a thin layer of dust or gases in the atmosphere“

“about half of the 18 scientific concepts of climate change were absent in the majority of the reviewed textbooks. Three of the textbooks neither distinguished among the types of radiation nor clarified how surface temperature is related to and distinct from infrared radiation“

“Six textbooks did not specifically mention that greenhouse gases are distributed in the atmosphere“

“Many students attributed global warming to an increase in incoming solar radiation, the Earth getting closer to the sun or the sun’s rays hitting more areas of the Earth”


*Clarification of scientific concepts of climate change.Simple and familiar analogies and descriptions are pedagogically useful and appropriate for younger students; however, without careful clarification, these helpful analogies and simple explanations can hinder, rather than help, students’ conceptual development…

*Connecting and differentiating scientific concepts. Students’ misconceptions about climate change are often due to an inability to connect interrelated science concepts…..

*Presenting the nature of climate change science. Most of the reviewed texts described the impact of climate change in terms of global warming and did not address the likely variability of impacts on regional scales…”
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Onsite Emissions from Building Construction

Toward Environmentally Sustainable Construction Processes: The U.S. and Canada’s Perspective on Energy Consumption and GHG/CAP Emissions

(17 page pdf, Sustainability 2010, 2, 354-370)
Key Quotes:
“The built environment .. accounts for approximately 40% of total energy use and associated greenhouse gas (GHG) emissions globally”
“the construction industry generates the third highest GHG emissions among U.S. industrial sectors.. did not account for on-site energy consumption from the use of electricity and natural gas”
“the construction sectors accounts for 6% of light on-road truck use and 17% of medium/heavy truck use in the U.S. “
“Among criteria air pollutants, construction equipment causes a disproportionately high share of PM2.5 and NOx in national inventories, equivalent to 2.1% and 3.9%” <for US and Canada…if the use of on-road trucks in construction is included, the CAP emissions from this industry would increase by 32% for PM10, 96% for NOx and 125% for VOC”
“Exhaust emissions from Canadian construction sectors .. cause a high share of NOx in Canada’s national inventories, equivalent to 5.5%…Fugitive emissions resulting from construction operations .. accounting for 18% of PM10 and 16% of PM2.5 in Canada’s national inventories. “
“a typical earthmoving operation under assumed conditions generates around 363 g of CO2, 4.7 g of NOx, 1.53 g of CO, and 0.037 g of PM for excavating 1 m3 of dirt”
“<LEED rating system> does not provide any credit to address directly exhaust emissions from operating construction equipment, which is the highest contributor of emissions from construction processes”
“two types of environmental incentives for reducing emissions from construction processes: grant programs, which provide direct funding to equipment owners to replace old equipment with new and cleaner equipment, and tax incentives, which offer tax exemptions, tax deduction, or tax credits to spur the use of technologies for reducing emissions”

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Top 5 myths about hybrid cars

Top 5 myths about hybrid cars (MSN Green Living Online)


Some responses to hybrid car myths.

Some say hybrids use as much if not more energy than conventional cars if one adds up the energy needed to manufacture them (one "myth" not answered below).

The 5 Myths and my reactions to the answers from MSN

"1. Hybrids lack power"

Some do, noting that those which have more power sacrifice gas economy

"2. Hybrids are expensive"

Yes - it takes 7-9 years to realize the savings from better gas mileage on average to recover the extra costs for the new hybrid

"3. Hybrids need to be plugged in"

- No, only the plug-in hybrids do but these are seen as the next generation of hybrid cars by some

"4. All hybrids have great fuel efficiency"

Some do but only in stop and start driving in cities. On the highway, conventional non hybrid cars are more efficient

"5. Hybrid batteries have a short lifespan and are expensive to replace"

Replacing these batteries can be 1/4 to 1/3 the price of the entire car.


Any comments from visitors to this blog?
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Benchmarks for Walking and Cycling

Bicycling and Walking In the United States: 2 0 1 0 Benchmarking Report (196 pages pdf, Alliance for Biking & Walking, 2010)
This report from the U.S. examines measurable indicators of walking and cycling, as well as comparison with other countries. Benchmark reports of this type have also been done in Canada in this report: Benchmarking Toronto’s Bicycle Environment: Comparing Toronto to other World Cities (2 page pdf, Toronto Coalition for Active Transportation, Apr. 25, 2008) and in this “ Online Benchmarking Tool” from the European Union which looks at various measures for 41 cities.
Over 1/3 of the population is either too young (under 16) or too old (over 65) to drive and this fraction will grow as society ages. Current and past urban design, aimed almost exclusively at driver comfort and convenience, ignores the needs of the young and old as well as the health impacts of congestion and pollution that accompany this. Benchmarks are a start to reverse this unsustainable trend.
Key Quotes:
“found the U.S. to have the second lowest bicycle share of trips when compared to several European countries, Canada, and Australia. Countries like the Netherlands and Denmark with 27% and 18% of trips by bicycle, respectively, are setting the benchmark for what is possible.”
“countries and cities that invest the most in bicycling and walking have higher bicycling and walking mode share, and are safer places to bicycle and walk.. [in the US]bicyclists and pedestrians make up over 13% of traffic fatalities and receive just 1.2% of federal transportation dollars”
“Over one-third of the U.S. population is under age 16 (cannot legally drive) or over age 65. Streets designed just to move cars are leaving behind the most vulnerable road users,”

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Proximity and Exposure to Air Pollution

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From Good Intentions to Proven Interventions: Effectiveness of Actions to Reduce the Health Impacts of Air Pollution (42 page pdf, Environ Health Perspect,  20 August 2010)

The article reviewed today reported on the association between proximity to high air pollutant concentrations and health impacts for various time intervals. It concluded that an number of important previously unaddressed steps could be taken to reduce those impacts, including land use planning and actions at individual health and fitness”

Key Quotes:

“For key pollutants such as particulate matter and ozone .., there are no established thresholds of exposure below which population health impacts are absent.”

“.. land use decisions typically do not consider air pollution-related health impacts and do not require minimum distances between sources and individuals. A consequence has been the siting of residences, schools and hospitals near major traffic arteries”

“must also consider .. relationship between increased sprawl and ozone concentrations .., as well as between increased neighbourhood walkability (via higher density, street connectivity and mixed-use design), and elevated concentrations of traffic related pollutants”

“Individuals residing within 50 m of a major road have a 63% excess risk of developing high coronary artery calcification compared with those living more than 200 m away from a major road”

“Extremely short term exposures to high PM levels can occur in many situations, including in traffic jams, at bus stops, in indoor parking garages, and at fireworks displays.. Short term exposure to diesel exhaust (1-2 hours) significantly reduces brachial artery diameter in healthy subjects and exacerbates exercise-induced ST-segment depression in people with pre-existing coronary artery disease

“In order to develop an optimal mix of community and individual actions, it is important to understand how long term, short term, and very short term (sub-daily, over the course of several hours) exposure to air pollution affects disease mechanisms and particularly disease progression and reversibility”
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