Pollution Free Cities: urban

Showing posts with label urban. Show all posts

Thursday, February 23, 2017

Estimating Greenhouse Gas Emissions for 100 Cities in the USA

Per capita anthropogenic greenhouse gas emissions by country for the year 2000 including land-use change. (Photo credit: Wikipedia)

An integrated approach for estimating greenhouse gas emissions from 100 U.S. metropolitan areas (12 page pdf, Samuel A Markolf, H Scott Matthews, Inês L Azevedo and Chris Hendrickson, Environmental Research Letters, Jan. 25, 2017)

Today we review an approach to estimate the emissions for a large number of cities in the USA which has advantages over the traditional bottom-up approach as well as likely being more accurate because it includes production as well as consumption of carbon emissions and fuels. Emissions from individual cities ranged from 5 metric tons per person in Tucson to 65 meteric tons per person in New Orleans. In gross terms, the average emission for the 100 cities examined was 27 million metric tons per year.

Key Quotes:

“over 80% of the United States’ population lives in metropolitan areas and roughly 75% of the earth’s natural resources are consumed in urban areas”

“bottom-up emission estimates for five sectors within a given city:

use of electricity by the community,
fuel use in residential, commercial, and industrial buildings (e.g.natural gas or fuel oil),
fuel use for on-road passenger and freight motor vehicle travel,
energy use in the treatment and distribution of potable water and waste water, and 5) emissions from the collection and degradation of solid waste generated by the community”

“the use of publically available national datasets to form metropolitan emission estimates significantly reduces the time, funding, and human capital that would otherwise be required for a traditional ‘bottom-up’ inventory”

“We find that total 2014 metropolitan CO2 emissions range from 4.1 million metric tons in Lancaster, Pennsylvania to nearly 170 million metric tons in the Houston, Texas; with an overall average of 27 million metric tons.”

“Per capita emissions also show a wide variation: from 5 metric tons per person in the Tucson, Arizona to 65 metric tons per person in the Baton Rouge, Louisiana”

“cities might consider conducting inventories about every 5 years and shift a greater portion of their time and energy toward mitigation efforts in the interim.”

Thursday, July 14, 2016

What Links Urban Metabolic Energy Flows and Urban Ecosystems – a literature review.

Eight energy and material flow characteristics of urban ecosystems (12 page pdf, Xuemei Bai, Ambio, Apr. 22, 2016)

Today we examine a review of current literature about two apparently conflicting urban concepts: one that is concerned with the material energy flows, the other with the ecology of wildlife and plants in a city environment. As cities become more complex and larger these concepts become more important in themselves, as well as between each other with intercity distributions and the regulation of processes across large urban areas and estimating the capacity of a city when to comes to the flow of materials, such as waste Approaching cities in this way also allows for a better defined environmental footprint, as demonstrated in one example in Barcelona, where a park designed for carbon sequestration was found after analysis to be one twelve the size needed to produce the desired absorption of carbon emissions from the city. The concluding words are worth noting: “A better understanding of the interactions between anthropogenic material and energy flows and ecosystem processes can help reduce unintended consequences of narrowly focused policy and management decisions.”

Key Quotes :

« The concept of urban metabolism has been widely used to study energy and material flows into and out of cities… recent urban energy and material flow studies have extended far beyond the original metaphor of cities as organism, and started to reveal important characteristics of urban system features and interactions.. Urban energy and material flow efficiency can be defined as how much social/economic services per unit of resource consumption or waste generation can support. It shows how efficient the urban system is in supporting its function, and is an important system performance indicator.”

“The input part of the urban metabolism includes various tangible materials such as food, water, construction and other materials, products, energy, as well as inflow of energy, capital, information, and people. Such input supports societal activities and drives urban functions within a city; forms urban stocks such as housing, building, infrastructure, and green parks; and produces products and services, as well as managed and unmanaged waste and emissions.”

“The output part consists of industrial products, services, knowledge, and various wastes and emissions. The magnitude, distribution, and internal interactions and feedbacks are regulated by policy, governance, culture, and individual and collective behaviour of the urban system.”

“Understanding biogeochemical budgets of ecosystems, in particular nutrients such as carbon, nitrogen, and phosphorus, has been one of the crucial elements of urban ecology” “The metabolic budget can be used to assess the total ecological footprints of cities”

“The total budget and pathways of material and energy flows reveal the magnitude of impacts and other important characteristics of urban system, such as the functional role of the city, development stages (i.e., mature or growing city), level of infrastructure and development, income, and other socioeconomic characteristics of the city”

Wednesday, June 4, 2014

How Polluted are the World’s Cities?

Ambient (outdoor) air pollution database, by country and city (Excel data base, World Health Organization, May 7, 2014)

Also discussed here: Ambient (outdoor) air pollution in cities database 2014 (World Health Organization, May 7, 2014)

And here: Air quality deteriorating in many of the world’s cities (Press Release, World Health Organization, May 7, 2014)

And here: Ambient (outdoor) air quality and health (World Health Organization, Fact sheet N°313, Updated March 2014)

And here: Top 20 most polluted cities in the world (Madison Park, CNN, May 8, 2014)

Today we review a report from the World Health Organization that presents the state of air quality in 1600 cities world-wide in an Excel data base that is easy to manipulate. Only 1/8th of the cities surveyed meet WHO guidelines for fine particulate matter (PM). Those that do better (examples Bogota, Colombia and Copenhagen, Denmark) do it by actively promoting cycling and walking. 88% of the 3.7 million premature deaths/ year because of air pollution occur in low and middle income countries and most of these are in the Western Pacific and Southeast Asia. 7 out of the 10 most polluted cities with the highest levels of particulate matter (PM10) are in Pakistan (Pakistan: Peshwar, Rawalindi and Karachi) or India (Gwalior, Ahvaz, Raipur and Delhi) while all 10 of the least polluted cities are in the USA (mainly in the southwest). Even in regions such as Europe, where WHO guidelines are generally met, lives are shortened by 8.6 months because of exposure to PM

.

PM10: Fine particulate matter of 10 microns or less; Amr: America, Afr: Africa; Emr: Eastern Mediterranean, Sear: South-East Asia, Wpr: Western Pacific; LMI: Low- and middle-income; HI: high-income. PM10 values are regional urban population-weighted.

Key Quotes:

“The database contains results of ambient (outdoor) air pollution monitoring from almost 1600 cities in 91 countries. Air quality is represented by annual mean concentration of fine particulate matter …The database covers the period from 2008 to 2013, with the majority of values for the years 2011 and 2012.”

“Only 12% of the people living in cities reporting on air quality reside in cities where this complies with WHO air quality guideline levels. About half of the urban population being monitored is exposed to air pollution that is at least 2.5 times higher than the levels WHO recommends - putting those people at additional risk of serious, long-term health problems.” “Guideline values: PM_2.5 10 μg/m³ annual mean, PM₁₀ 20 μg/m³ annual mean”

“Too many urban centres today are so enveloped in dirty air that their skylines are invisible…Not surprisingly, this air is dangerous to breathe. So a growing number of cities and communities worldwide are striving to better meet the needs of their residents - in particular children and the elderly."

“even in the European Union, where PM concentrations in many cities do comply with Guideline levels, it is estimated that average life expectancy is 8.6 months lower than it would otherwise be, due to PM exposures from human sources.”

“No Chinese cities ranked in the top 20 most polluted cities, despite thick, gray smog filling its cities and millions of residents commuting behind surgical masks.”

“Effective policies and strategies are well understood, but they need to be implemented at sufficient scale. Cities such as Copenhagen and Bogotà, for example, have improved air quality by promoting ‘active transport’ and prioritizing dedicated networks of urban public transport, walking and cycling.”

“Half of the top 20 cities in the world with the highest levels of PM2.5 were in India…Other cities with high levels were located in Pakistan and Bangladesh.”

“Ambient (outdoor air pollution) in both cities and rural areas was estimated to cause 3.7 million premature deaths worldwide in 2012….The Guidelines indicate that by reducing particulate matter (PM₁₀) pollution from 70 to 20 micrograms per cubic metre (μg/m), we can cut air pollution-related deaths by around 15%.”

Wednesday, April 9, 2014

Polling the Public about Air Pollution

Air Quality in London Survey(Transport for London, Mar. 2014)

Today we review a dozen questions that the Mayor Johnston has posed to his citizens about the state of air pollution London which recently reached record levels, comparable to those in the capital of China. Action to improve air quality (or other environmental issues such as climate change) from the public purse has to be based on how tax payers perceive the problem and its sources, as well as which options they might accept or hopefully endorse. Londoners are lucky to have Mayors who care enough about the environment to take significant steps to improve it, as we have seen in the implementation of the Low Emissions Zone, using a congestion charging system in the core of London over 10 years ago. What comes next? We’ll see after the poll closes in mid-April.

Key Quotes:

“What do you think are the causes of air pollution in London? (please tick as many as you feel appropriate)

	Yes	No	Don't know
Road traffic	Yes	No	Don't know
River traffic	Yes	No	Don't know
Aviation	Yes	No	Don't know
Trains	Yes	No	Don't know
Construction (e.g. building sites)	Yes	No	Don't know
Industry (e.g. manufacturing)	Yes	No	Don't know
Domestic (home heating)	Yes	No	Don't know
Weather	Yes	No	Don't know

“ Do you agree to reduce pollution from traffic we should:

	Yes	No	Don't know
Encourage people to walk and cycle more	Yes	No	Don't know
Encourage people to reduce their private car use	Yes	No	Don't know
Encourage people to reduce their use of all vehicles (including taxis and buses)	Yes	No	Don't know
Encourage people to travel at different times of the day to reduce congestion	Yes	No	Don't know
Encourage more people to work from home	Yes	No	Don't know
Encourage people to use cleaner fuelled vehicles	Yes	No	Don't know
Encourage people to use vehicles powered by alternative fuels and / or alternative technologies	Yes	No	Don't know

Friday, December 27, 2013

How Does Polluted Air Affect Your Eyes?

Residents of most polluted US cities -- New York City, Chicago, Los Angeles and Miami -- have increased risk of dry eye syndrome(Press Release, American Academy of Ophthalmology, Nov. 16, 2013)

Also discussed here: Residents of Most Polluted US Cities Have Increased Risk of Dry Eye Syndrome(Science Daily, Nov. 16, 2013)

And here: Dry Eye Syndrome Linked To Big City Air Pollution (Matthew Mientka, Medical Daily, Nov 17, 2013)

And here: Environmental Factors and Dry Eye Syndrome: A Study Utilizing the National U.S. Veterans Affairs Administrative Database (PO052)(Anat Galor, paper presented at 117th Annual Meeting of the American Academy of Ophthalmology, Nov. 16-19, 2013)

Today we review a paper that examined the link between air pollution and a deficiency in tear production, dry eye syndrome, that affects up to 21% of the population in cities with high levels of air pollution such as Los Angeles, Chicago, Miami and New York. The resulting impact produces stinging eyes and the production of more tears that make it difficult to read or view computer screens.

Key Quotes:

“Dry eye syndrome, a deficiency in tear production, is a prevalent condition that effects up to four million people age 50 and older in the United States”

"Those living in areas with high levels of air pollution had the highest magnitude of increased risk for dry eye syndrome, at an incidence rate ratio of 1.4. Most metropolitan areas, including New York City, Chicago, Los Angeles and Miami showed relatively high prevalence of dry eye syndrome (17 to 21 percent) and high levels of air pollution.”

“a deficiency in tear production, affects as many as 4 million Americans ages 50 and older, with symptoms affecting physical and mental functioning, including the interruption of activities important to modern functioning: reading printed materials as well as on-screen material”

“Symptoms of the potentially painful and disruptive condition range from stinging or burning to excessive tearing and discomfort wearing contact lenses. Responding to the irritation, the eye often tears excessively to compensate for lost moisture, inhibiting the ability to read, or use a computer for extended periods of time”

“Aside from Chicago and New York City, major cities such as Miami and Los Angeles also recorded high levels of air pollution as well as higher than average prevalences of the condition. In big cities, as many as 17-21 percent of the populations in major cities may suffer the condition.”

Friday, December 6, 2013

How Quickly are Cities Growing and What are the Environmental Consequences?

Choking on their own growth(24 page pdf, Lars Martin Hjorthol, pages 17-20, Gemini, NTNU, spring 2013)

Today, we review an article in « Gemini », the magazine of NTNU, the technical university located in Trondheim, which has formed a multidisciplinary group of researchers looking at “urban ecology”. The article looks at the population growth of cities, especially in Africa and Asia, over the last 50 years, how urban development has proceeded and what needs to be done in the future. A major observation is that traditional Western development policy with its accent on sprawling suburbs, has unfortunately took hold in some cities. Urban development must be adapted bottom-up to the particular needs of the inhabitants who see secure property ownership as most important along with health safety and transportation.

Key Quotes :

"Almost the entire global population increase over the next decades will take place in the cities of the south. The population in cities has increased fivefold since 1950, increasing by 60 million a year, according to UN figures…By 2050, there will likely be well over nine billion people on Earth, 70–75 per cent of whom will live in cities …In 1950, all of Africa’s cities combined had a population of 33 million. But that number may grow to as much as 1.3 billion by 2050,”

“Everything seemed chaotic. And I thought like a traditional urban planner, with ready made solutions to what I perceived as the main problems. But what we first thought was most important to people in the area, proved to be far down on their priority list. Their top priority is more secure property ownership and tenancy,”

“Instead of asking what does not work, we start with what they have, and build on local resources. We have to build on their strengths, not their weaknesses,”

“The greater the degree of urbanization, the stronger the economy. Europe and the US have an urbanization rate of nearly 90 per cent. China passed the tipping point of having 50 per cent of its population as city dwellers in January 2012 and will probably exceed 70 per cent by 2050.”

“Internal inequality is a major cause of many problems in rapidly growing cities, when it comes to health, safety, transportation and other infrastructure,”

“But the Chinese are still stuck in a traditional Western planning paradigm, with suburbs and car-based land use. This approach is already about to collapse in several places. We see almost no bicycles in Beijing anymore. Instead, cars are stuck in endless queues, and move much more slowly than bikes used to do,”

“Major cities in developing countries often have higher emissions of greenhouse gases per person than in rural areas (while the opposite is often true in developed countries).”

“Urbanization has not been covered in this way in previous IPCC reports. Now there’s a chapter on urbanization in both the sub-report on emissions reductions and in the chapter on adaptation,”