Tag Archives: environment

Santa Cruz Greenbelts

by Matthew Pinsker
University of California, Santa Cruz
Daniel Matthew Silvernail Architect Intern

Greenbelts within Santa Cruz, California are endangered and this may be due to a lack of support from state legislation. Greenbelts alias urban growth boundaries are local government sanctioned demarcations that control urban sprawl by respectively maintaining a fixed juxtaposition between rural and urban areas.

Pogonip Greenbelt located in NW Santa Cruz, CA

Pogonip Greenbelt located in NW Santa Cruz, CA

California legislation requires what are known as spheres of influence, defined as planning boundaries or city limit lines that regulate the jurisdiction of governmental agency services, but do not manage urban growth.

Potential positive outcomes of growth regulation include efficient use of public facilities, promotion of long-term strategic thinking, and protection of open space. Santa Cruz greenbelts may be endangered as a result of current California requirements, allowing cities to manage urban sprawl upon evaluation of their needs through long-term urban planning strategies.

Local California governments appear to manage greenbelts in accordance with rules governing spheres of influence, as required by legislation. In the article “Growth Management Policy in California Communities” by Elisabeth R. Gerber and Justin H. Phillips they explain varying processes and contexts for altering California greenbelts. “…boundaries adopted by city councils tend to only require the approval of the council, country board, a Local Agency Formation Commission (LAFCO), or another outside governmental agency to be altered…none of the UGBs [urban growth boundaries] that originated from a successful citizen initiative have been significantly changed” (6).

Gerber and Phillips discuss the positive outcomes of increasing citizen interest in local greenbelts, producing a decrease in the likelihood of greenbelt endangerment, allowing internal efficiency and forethought to flourish. The potential for greenbelt enforcement seems to rely on public activism and awareness of California legislative processes, which would likely reinforce stringent urban growth boundaries. Materialization of this state ordinance is apparent within Santa Cruz, California where local greenbelt management is municipally planned through long-term development.

Wilder Ranch State Park located in SW Santa Cruz, CA

Wilder Ranch State Park located in SW Santa Cruz, CA
Photo by ATMTX Photography

Santa Cruz has delineated its boundaries through acquiring greenbelt properties over time and managing them within the legal framework of California. The “City of Santa Cruz 2030 General Plan” discusses the city’s greenbelt acquisition and implementation process, “At the time [1994], the City already owned several key properties in the greenbelt, and by the end of 1998, had purchased all of the Greenbelt properties with the exception of one…The preservation and use of each Greenbelt property and open area is guided by a City-prepared long term Park Master Plan…” (121).

The city of Santa Cruz Planning and Community Development Department explicates the history of local greenbelt acquisition with long-term plans set aside for preservation and future development where appropriate.

This process of long-term planning does not require growth management but upholds expansion with the city’s best interests in mind. The delineating function of greenbelts within Santa Cruz appears to recognize that cities are prone to sudden change and it is the task of the local government to strategically plan for fluctuations in community needs.

Greenbelts within the city of Santa Cruz are currently threatened under California legislation, which does not require direct management of urban growth. A proposed incipient stage to maintaining current greenbelts is to encourage citizen activism and awareness in the form of resolute initiatives to ultimately encourage definitive boundaries and internal development.

Through valid property accumulation the city’s management of greenbelts limits such initiatives, rather California legislation appears to advocate long-term development from an autonomous perspective. Santa Cruz greenbelts are indeed endangered but urban growth management can be employed in various fashions, universal sanctions for the sake of immutable city limits or appropriate adjustments according to population and resource projections.

The implementation of greenbelts is presented as contingent upon guiding state ordinances that lay the framework for how and under what circumstances cities should respond to preservation and development.

List of Santa Cruz Greenbelts:

Antonelli Pond
Arana Gulch
Arroyo Seco Canyon
DeLaveaga Park
Henry Cowell State Park
Jessie Street Marsh
Lighthouse Field
Moore Creek Preserve
Neary Lagoon
Wilder Ranch State Park
Younger Lagoon

To learn more about the city of Santa Cruz, a helpful resource is the City of Santa Cruz Official Government Website.  Santa Cruz Park Locations, the Zoning District Map, the General Plan Land Use Map, and much more are located at City of Santa Cruz: Area Maps.

Works Cited:

City of Santa Cruz Planning and Community Development Department. “City of Santa Cruz 2030 General Plan.” n.p. (2012): 1-210. Web. 5 March 2014.

Gerber, Elisabeth R. and Justin H. Phillips. “Growth Management Policy in California Communities.” Center for Local, State, and Urban Policy: University of Michigan 1.2 (2004): 1-7. Web. 3 March 2014.

Net-Zero Buildings


One NZE building: the Research Support Facility in Golden CO, approximately 50% more efficient than it’s conventional counterparts.

The noted American green building architect William McDonough is famously quoted as once saying that buildings should, among other qualities, “live off current solar income”. What was merely a hypothetic concept in the early 1990’s has since firmly taken root: Net zero energy (NZE) has taken on significant momentum as one of the factors shaping the sustainable construction movement.

With the U.S. Department of Energy’s 2009 mandate that all new federal buildings will be NZE by 2030, deployment of NZE is now national policy. Beginning with the city of Austin, TX in 2009, local jurisdictions have since followed suit. Here in California, the next iteration of the Title-24 Energy Code (scheduled for July 1st) will require all new residential buildings to be NZE by 2020 and new commercial buildings to conform by 2030. As a relatively new concept in the construction industry, much ambiguity still exists as to terminology, definitions, and usage of the term Net Zero Energy.

A useful description can be found in “Sustainable Construction: Green Building Design and Delivery” which offers, “In general, these are grid-connected buildings that export excess energy produced during the day and import energy in the evenings, such that there is an energy balance over the course of the year. As a result, NZE buildings have a zero annual energy bill with the added bonus that they are considered to be carbon neutral with respect to their operational energy.”

In her popular and highly influential book Energy Free: “Homes for a Small Planet” (Green Building Press, San Rafael, CA), Ann Edminster offers four (4) definitions, each taken from a different perspective e.g. energy usage at the project site, usage at the energy source, cost of the energy used, and by emissions associated with the energy usage. Of these, the most useful are the first and the last.

The first of these, again taken from the perspective of the building, reads: “Net-zero site energy (Definition 1). A site zero energy building produces at least as much energy as it uses in a year when accounted for at the site”.

The fourth definition reads, “Net-zero energy emissions (Definition 4). A net-zero emissions building produces at least as much emissions-free renewable energy as it uses from emissions-producing energy sources.”

In Europe, the most influential leadership towards NZE seems to be that of the International Energy Agency (IEA), an NGO based in France. Working within the framework of IEA’s “Solar Heating and Cooling Program Task 40: Energy in Buildings and Communities” initiative, researchers in 14 European countries plus the U.S., Canada, Singapore, Korea, Japan, Australia, and New Zealand are working to bring NZE into international market viability.


Rendering of NREL’s Research Supporting Facility depicting just a few of its “green” features.

A good exemplar of an NZE building in this county is the National Renewable Energy Laboratory’s Research Support Facility (RSF), located in Golden, Colorado. This 360,000-square-foot, four-story office building’s energy use goal is estimated at 34.4 kBTU/ft2/yr. According to U.S. EPA’s Energy Star, the national median site EUI for office buildings is 67.3 kBTU/ft2/yr, making the RSF approximately 50% more efficient than it’s conventional counterparts.

To learn more about NZE, some helpful resources include the U.S. Department of Energy Building America website, that of the Solar Heating and Cooling Programme, and Zero Energy Buildings: A Critical Look at the Definition.

Buildings and Light Pollution

Ecological light pollution is the effect of artificial light on individual organisms and on the structure of ecosystems as a whole.

When animals live in cities, they have to adjust their behavior and life histories to novel environments. Noise pollution puts a severe constraint on vocal communication by interfering with the detection of acoustic signals. Recent studies show that city birds sing higher-frequency songs than their counterparts in non-urban habitats. This has been interpreted as an adaptation to counteract masking by traffic noise.

Similarly, anthropogenic light and noise have modified differences between day and night, and may thereby interfere with their circadian clocks. Urbanized birds as well as many other species are known to advance their activity into early morning and night hours. Studies indicate that city birds start their activity earlier and had faster but less robust circadian oscillation of locomotor activity than their forest relatives. Circadian period length predicted start of activity in the field, and this relationship was mainly explained by fast-paced and early-rising city birds.

 In the article “Ecological Light Pollution” from the publication Frontiers in Ecology and the Environment by the Ecological Society of America it is reported that “through the various effects that light pollution has on individual species, the ecology of regions is affected. In the case where two species occupy an identical niche, the population frequency of each species may be changed by the introduction of artificial light if they are not equally affected by light at night. Changes in these species frequencies can then have knock-on effects, as the interactions between these species and others in the ecosystem are affected and food webs are altered. These ripple effects can eventually affect even diurnal plants and animals. As an example, changes in the activity of night active insects can change the survival rates of night blooming plants, which may provide food or shelter for diurnal animals.

The introduction of artificial light at night is said to be one of the most drastic anthropogenic changes to the Earth, comparable to toxic pollution, land use change, and climate change due to greenhouse gases.

The Urban Heat Island Effect


Aerial view of the city of Los Angeles California

An urban heat island is the name given to describe the characteristic warmth of both the atmosphere and surfaces in cities (urban areas) compared to their non-urbanized surroundings. The heat island is an example of unintentional climate modification when urbanization changes the characteristics of the Earth’s surface and atmosphere.

As cities add roads, buildings, industry, and people, temperatures in the city rise relative to their rural surroundings, creating a heat island. These urban heat islands may be up to 10-15°F warmer under optimum conditions. With increasing urban development, heat islands may increase in frequency and magnitude. Los Angeles, California, for example, has been 1˚F hotter every decade for the past 60 years. These heat islands have impacts that range from local to global scales and so represent a significant impact on environmental change.

There are three types of heat islands: 1). canopy layer heat island (CLHI), 2). boundary layer heat island (BLHI), and, 3). surface heat island (SHI).

The first two refer to a warming of the urban atmosphere; the last refers to the relative warmth of urban surfaces. The urban canopy layer (UCL) is the layer of air closest to the surface in cities, extending upwards to approximately the mean building height. Above the urban canopy layer lies the urban boundary layer, which may be 1 kilometer (km) or more in thickness by day, shrinking to hundreds of meters or less at night. It is the BLHI that forms a dome of warmer air that extends downwind of the city. Wind often changes the dome to a plume shape.

Heat island types vary in their spatial form (shape), temporal (related to time) characteristics, and some of the underlying physical processes that contribute to their development. Scientists measure air temperatures for CLHI or BLHI directly using thermometers, whereas the SHI is measured by remote sensors mounted on satellites or aircraft.

A number of factors contribute to the occurrence and intensity of heat islands; these include: 1). weather, 2). geographic location, 3). time of day and season, 4). city form, and 5). city functions.

Weather, particularly wind and cloud, influences formation of heat islands. Heat island magnitudes are largest under calm and clear weather conditions. Increasing winds mix the air and reduce the heat island. Increasing clouds reduce radiative cooling at night and also reduce the heat island. Seasonal variations in weather patterns affect heat island frequency and magnitude.

Geographic location influences the climate and topography of the area as well as the characteristics of the rural surroundings of the city. Regional or local weather influences, such as local wind systems, may impact heat islands; for example, coastal cities may experience cooling of urban temperatures in the summer when sea surface temperatures are cooler than the land and winds blow onshore. Where cities are surrounded by wet rural surfaces, slower cooling by these surfaces can reduce heat island magnitudes, especially in warm humid climates.

City form comprises the materials used in construction, the surface characteristics of the city such as the building dimensions and spacing, thermal properties, and amount of greenspace.

Heat island formation is favored by: 1). relatively dense building materials that are slow to warm and cool and store a lot of energy, 2). replacement of natural surfaces by impervious or waterproofed surfaces, leading to a drier urban area, where less water is available for evaporation, which offsets heating of the air, and 3). lower surface reflectivity to solar radiation — dark surfaces such as asphalt roads absorb more sunlight and become much warmer than light-colored surfaces.

City functions govern the output of pollutants into the urban atmosphere, heat from energy usage, and the use of water in irrigation. Anthropogenic heat, or heat generated from human activities, primarily fossil fuel combustion, can be important to heat island formation. Anthropogenic heating usually has the largest impact during the winter season of cold climates in the downtown core of the city. In select cases, very densely developed cities may have significant summertime anthropogenic heating that results from high energy use for building cooling.

Your Ecological Footprint

Recycle BuildingEcological footprint is a term commonly used in sustainable building practice as a measure of our demand on earth’s resources. More specifically, it represents the amount of biologically productive land and sea area necessary to supply the resources necessary to a given population. Since resource utilization is dependent on personal lifestyle, the ecological footprint can be considered to be a quantification of the demand for natural capital needed to support a given lifestyle.

This unit of measure was first conceptualized in the PhD dissertation of Mathis Wackernagel under the supervision of William Rees at the University of British Columbia in Vancouver in 1988. Originally the two men called their concept “appropriated carrying capacity”. The revised term, “ecological footprint”, was coined in their book, “Our Ecological Footprint: Reducing Human Impact on the Earth” in 1996.

When calculated at the level of cities and countries, the measure provides a useful indicator of the relative demand on resources for any given population base. An ecological footprint calculation indicates that, for example the Dutch need a land are 15 times the physical footprint of the Netherlands to support their population. The population of London requires a land area 125 times greater than its physical footprint. William Rees’ ecological footprint analysis of his home city of Vancouver, Canada indicates that Vancouver appropriates the productive output of a land area nearly 174 times larger than the city’s physical area to support its lifestyle.

When considering the ecological footprint on the individual level, given Earth’s 8.9 billion hectares of productive land and its 6 billion human inhabitants, the average ecological footprint comes to roughly 1.5 hectares per person.  This per-capita footprint provides a benchmark from which to assess the long-term sustainability of material consumption.  Accordingly, individual footprints below 1.5 hectares are sustainable and footprints above 1.5 hectares are not. Wackernagel and Rees’ original calculations indicate that inhabitants of industrialized countries often have footprints as large as four (4) to ten (10) hectares, i.e. up to six times the carrying capacity of the planet.

What is your personal ecological footprint? A number of non-governmental agencies (NGOs) offer online ecological footprint calculators. One of them is at Footprint Calculator.

Some resources available for further reading include Wackernagel’s original thesis “Ecological Footprint and Appropriated Carrying Capacity: A Tool for Planning Toward Sustainability” and William Rees’ 1992 paper, “Ecological Footprints And Appropriated Carrying Capacity: What Urban Economics Leaves Out“.

The San Francisco Federal Building

San Francisco Federal Building

San Francisco Federal Building

Most of us have noticed the new Federal Building complex in South of Market – it’s readily apparent and distinctive from both the route 101- and 80- freeways. Fewer are aware that the building is widely regarded as a cutting-edge example in the art of high-performance green building.

Owned by the Government Services Administration (GSA), the facility serves the Social Security Administration, Department of Labor, Department of Health & Human Services, and the Department of Agriculture. The design team was led by Morphosis Architects of Los Angeles and included the LA office of Ove Arup for the integrated structural and mechanical design.

The complex consists of several components including a four-story structure housing the SSA, an undulating form at plaza level accommodating a day-care center and cafeteria, and the dominant, 18-story tower.


The perforated skin of the Federal Building controls light and airflow through the building

The folded, perforated metal skin covering much of the southeast face of the tower assists in the flow of air throughout the structure – this façade is also covered with perforated panels that rotate to control daylighting as well as provide unobstructed views across the city. The thin-section organization of the tower facilitates passive cooling and ventilation throughout the structure, taking advantage of ambient air temperatures and air currents around the building and directing them via building elements, including the perforated skin, that direct the deep penetration and circulation of outside air.

Altogether, the net result of these strategies is to realize a 26% reduction in lighting energy and a 39% reduction in mechanical systems energy compared to average GSA building usage.

Living Machines


The Living Machine at Lewis Center for Environmental Studies at Oberlin College

One of the ultimate goals of green building is the application ecological design to the greatest extent possible, including a synergistic relationship between natural systems, buildings, and human inhabitants.

The use of wetlands to treat wastewater effects of buildings is well known and is becoming mainstream – most of us are familiar with the use of landscaping bioswales to filter storm water effluent before discharging it back into the aquifer.

A more exotic and robust use of ecosystems to treat building effluent is the so-called Living Machine, in which nature is brought directly into a built structure in order to break down the effluent – both greywater and blackwater – as part of the wastewater treatment system. Several approaches are in use, although the best known is said to be that pioneered by John Todd, an early exponent of the development of natural wastewater processing systems.

Contrasted with conventional wastewater treatment plants, a Living Machine is different in four major ways:

  1. A Living Machine fundamentally relies on living organisms, rather than mechanical parts, to produce work. These “cogs” in the machine can include hundreds of species of bacteria, plants, invertebrates, and even vertebrates including fish and reptiles.
  2. A Living Machine regulates its own internal ecology in relationship to the energy and nutrient streams feeding it.
  3. Should it be stressed by toxic substances or by interruption of its energy or nutrient streams, the Living machine is self-healing and self-regulating.
  4. A Living Machine is capable of self-replication through the propagation of its constituent organisms.

Among the most famous examples of Living Machine is that at the Lewis Center for Environmental Studies at Oberlin College in Oberlin OH. Local, regional examples occur at San Francisco Public Utilities Commission (SFPUC) Headquarters, San Francisco and at Esalen Institute in Big Sur.

They Built Their Own Demise: Lime Mortar, Render, and Plaster: What Role in the Decline of Classical Mayan Civilization?


Chitzen Itza, west facade of the temple called “El Castillo” constructed c. 600AD. Constructed of hewn limestone blocks and whitewashed in lime plaster, the original plaster render has not survived the centuries.

A flat shelf made from the structures of ancient animals, the Yucatan was uplifted from the seabed around 10 million years ago. With its emergence from the seabed, plants arrived. Around 2500BC it is believed that the people destined to become the Maya arrived on the peninsula.

Through many generations, the Maya became the builders of cities. Each city-state of the Maya was centered at its core upon the focal buildings, the edifices signifying the status of the city, the focal point of rulership, and the city’s relationship to the gods. In the Mayan city the focal buildings generally included temples, observatories, and ballcourts. The temples served as the structures dedicated to communication with the divine, the observatories were dedicated to communication with natural cycles, and the ballcourts were associated, among other roles, with resolving internecine rivalries between city-states.

Rendering, west facade, Temple of the Descending God at Tulum depicting the painted lime plaster render typical of Mayan edifices.

Rendering, west facade, Temple of the Descending God at Tulum depicting the painted lime plaster render typical of Mayan edifices.

Each city-state had its own quarry from which the massive blocks of limestone, buildingblocks for the edifices, were hewn. More significantly, every important edifice was apparently whitewashed, as it were, with a keen layer of lime plaster and then painted in vibrant colors. Once fitted together and assembled, the building’s presentation relied on lime plaster to achieve the desired effect. The very laying up of the blocks themselves depended on lime mortar to hold them in place. Thus the architecture of the Maya depended on limestone and lime plaster for their very viability.

The conversion of limestone into either mortar or plaster relies on availability of the raw material (limestone), a ready source of fresh water, and heat. In the Yucatan the stone was readily available, and freshwater also readily available from the cenotes, the underground chambers of the Yucatan where water naturally collects. But for heat, the Maya could only rely upon the burning of forests, and the resulting deforestation is thought by many to be perhaps the ultimate reason for the collapse of Mayan civilization.


West facade, Temple of the Descending God at Tulum. Photograph by the author, July 9th, 2013.

The Maya harvested the forests around their cities to produce the heat sources necessary to the conversion of raw limestone into the mortar and plaster needed for their building projects. For plaster render, it is estimated that many square miles of deforestation were required to produce each square foot of rendered plastered surface area.

Multiply these estimates by the many thousands of building structures erected by the Maya and one can see that the baseline impacts of Mayan architecture upon the ecology could not have been slight. Add to this impacts resulting from internecine rivalries between rival city-states, and one can perceive what may have been a tipping point in the ecology of the Maya.

Competition between the Mayan city-states is well known. For example, the 60 mile causeway from Coba in the south to it’s sister-city Yaxuna in the north is understood to have been constructed for purposes of military defense of Yaxuna, ally of Coba, against the aggressions of city-state of Chitza-Itza and it’s allies.

Each Mayan city itself could be seen as the focal point for competitive interaction between rival states. As each city-state grew and naturally sought to aggrandize its own interests, other city-states sought to aggrandize theirs. Objectifying the legitimacy of the city-state required the construction of monuments, and the construction of monuments demanded resources: the quarrying of stone, harvesting of water, the deforestation of trees.

Thus, even as trees were burned to fuel the construction programs necessary to the city-state – the edifices, monuments, the roads – upon whose efforts the citizens were focused, the resources themselves were stretched beyond their carrying capacity. As the forests became overharvested, competition for the resources essential to the Mayan city-state grew commensurately, even as the carrying capacity of the land was diminished.

At the time of the invasion of the Spanish Conquistadores according to most accounts the Mayan cities were apparently by and large mostly abandoned. Tulum, on the east coast, remained among the viable Mayan cities, most others having been abandoned by the time of the arrival of the Spaniards.

Environmental degradation leading to war in turn fomenting increased competition for natural resources is not, of course, the only theory available to explain what became of the Mayan city-state – other theories abound. Having said that, the amount of environmental degradation necessary to the construction of the architecture of the Mayan city is quantifiable. What have not been quantified are the internecine and political factors which fed into their architecture, and consequent demand for resources which may have led to their demise.

Photovoltaic Assessment with Consumers in Mind

Dear Reader,

This is the first in the series of contributions to our blog by Anna Medina, Daniel Silvernail Architect- UCSC Green Building Intern. We welcome Anna to our team!

PhotovoltaicsWhen considering going solar, it is important to understand the financial costs and varying scales of environmental benefits associated with different systems. Navigating through the myriad of options for solar panel types, sizes and installers, it is difficult to assess the degree to which you are making an environmental difference for the finances you are supplying. Finding a system that is right for you is influenced by several factors such as scale, efficiency, life span and the installation company you choose to use. These decisions most directly affect the cost of your solar system, however, the purpose of this article is to better inform your decision in which panel technology you invest in, and to reassure your transition to solar power.

The difference in photovoltaic cells is characterized by the elements they use. The two most prominent materials used in photovoltaic’s are silicon and cadmium telluride (CdTe). Silicon is the second most abundant element in the world, after oxygen, which eliminates issues of resource scarcity and the extensive mining patterns associated to retrieving rare earth minerals. The consequences of silicon mining are minimal in comparison to coal and petroleum, since there are zero carbon emissions and it is not an environmentally hazardous substance. On the other hand, CdTe is known to be ecologically toxic, but is most commonly acquired as a byproduct of zinc winning. Thus, employing CdTe in solar panel production is an effective way in diverting toxic waste from landfills. CdTe remains in the solar market behind silicon panels because it tends to be more cost effective, although less energy efficient. Overall, both silicon and CdTe models are sustainably comparable, however, the production and manufacturing of silicon panels poses less risks because it is a non-toxic substance.

The environmental analysis of solar energy extraction, production and waste disposal operations make evident the significant environmental advantages over traditional coal and petroleum. While there is no perfect solution to meeting our energy demands with zero environmental impact, solar energy is the best option available. Operations with preferable extractive techniques and relying on abundant materials, solar energy is the most viable alternative to coal and petroleum. Going solar ensures the availability of energy with minimal impact on the environment while also alleviating energy dependence on fossil fuels.

Announcing the DMSA-UCSC Green Building Internship Position

It’s exciting to announce that we’ve created and staffed an internship position in collaboration with the Department of Environmental Studies at the University of California, Santa Cruz.

This the is second internship position we’ve created in association with affiliate agencies, the first being the extremely successful DMSA-USGBC Emerging Green Professional Internship.

Anna Medina, major in Environmental Studies at UCSC has been accepted and has acceded to the newly created post.