Population study finds environmental degradation after area reaches population of 200,000; Current build-out population estimated at 400,000 people
By Brian Wheeler
Sunday, August 23, 2009
on local population and the environment, funded in part by both Charlottesville and Albemarle local governments, was released last week by
Advocates for a Sustainable Albemarle Population
Board of Supervisors agreed to spend $25,000
for the scientific
aspects of the study, and the City of Charlottesville paid $11,000.
Additional funding came from ASAP members as well as a $50,000 grant
from the Colcom Foundation of Pittsburgh, Pennsylvania.
The report, the first product of ASAP’s
Optimal Sustainable Population Size Project
, is entitled “Estimating Impacts of Population Growth on Ecosystem Services for the Community of Albemarle County and Charlottesville, VA.” The report’s principal researcher was
Dr. Claire Jantz
, an assistant professor at Shippensburg University.
Charlottesville Tomorrow invited
, ASAP’s President, in for an interview to discuss the report’s findings.
Podcast produced by Charlottesville Tomorrow * Player by Odeo
Listen using player above or download the podcast:
JACK MARSHALL INTERVIEW
Note: Remarks have been summarized and are not necessarily direct quotes. The podcast includes the entire interview audio.
IMES CORRESPOND TO AUDIO PODCAST
00:27 – Introduction by Brian Wheeler, Executive Director, Charlottesville Tomorrow
WHEELER: What is the major finding of this research?
: Report is intended to help us understand how we define an optimal population. First phase of research is to help identify biological carrying capacity of the Charlottesville-Albemarle community. Report shows that as growth occurs, two things happen together: 1) good things like fields and forests disappear; and 2) bad things occur like impervious surfaces and pollution. Continued growth will so impair ecosystem services that our community will not be locally sustainable. Smart growth approaches (e.g. having designated growth areas) are necessary, but they are not sufficient. Growth will ultimately spill out into rural areas. Researchers are saying that we have to think about how big we want to be. Do we want to cap growth before we reach these ecological danger points?
WHEELER: Why did you do this research and can you tell us about the research team?
: First, the research team was led by Dr. Claire Jantz , an assistant professor at Shippensburg University. She is a specialist in land use change modeling. We asked her to do this because as housing developments eat away at our environment, something has to give. Our ecological system is not just a pretty face, they provide benefits of immense value to humans that we tend to take for granted and they are essential for sustainability of an area. If they get degraded, the community is in trouble, and we wanted to see if local growth had a local impact on our very own ecosystem services.
WHEELER: Why don’t you tell us about the methodology.
: For purposes of this research, WHEN growth occurs is not relevant. First step was to project WHERE the growth will occur. The City and County were divided into eight sub-areas and various growth levels were evaluated in a computer model. Current zoning and historical development patterns were incorporated in the model. Hypothetically, each area is developed to a certain build-out number, and then continued growth spills out into the rural area. The population number at which no more development could occur in the computer model was found to be 400,000 people. We have about 135,000 people today. This build-out population estimate of 400,000 is pretty close to research done by a different methodology 5-7 years ago by the Thomas Jefferson Planning District Commission (TJPDC). Next major issue was to assess impact to ecosystem services with population growth using computer software called CITYGreen.
WHEELER: You mentioned a couple population numbers, let’s review those again—135,000 people today, build-out population of 400,000. Were you surprised that matched the TJPDC’s findings?
: The fact that it coincides with the TJPDC build-out number pleases but doesn’t surprise us.
WHEELER: What optimal sustainable population did this research indicate was a good fit?
: You are pushing me to give you specific numbers, but all this research does is show what happens to certain ecosystem services as population increases. At 125% population increase, which is about 280,000 people, roughly twice what we have now, there is in this model a degradation of ecosystem services, but contained primarily within the designated growth areas. As growth continues, it spills out into the rural areas, and that’s when we see a whole different level of impact. This report goes into detail about those impacts on ecosystem services.
WHEELER: Let me read a quote from the report and you can react to it
“If the community wishes to maintain ecosystem services across the study area, a population of roughly 200,000 or less should be maintained, with that growth being focused in the growth areas. If it is acceptable to sacrifice services in the developing areas, a population up to roughly 300,000 could be accommodated.”
Is 200,000 to 300,000 the population range that ASAP was looking for?
: You are trying to get me to indicate a number or a range that ASAP wants to defend. At this point we are not prepared to come out with specific numbers. This is the first phase of the study focusing on biological carrying capacity. Once we have the whole range of studies completed this fall, then we will be more inclined to come out with specific numbers.
WHEELER: Let’s talk about the population trends. She identified 200,000 as a population not to go beyond to avoid damaging ecosystem services. How soon do you think we will reach 200,000 people?
: City population is pretty stable, but County has been growing at 2.1% a year for the last 30-40 years. At that rate, we double our population every 33 years. Normally I would say you could extrapolate that, but we have slowed growth because of the global economic downturn. There is no question that temporarily we are growing slower. I am afraid that might lull our community into a false sense that we have licked the growth problem when in fact it will roar back as soon as people want to buy houses again.
If we were to continue growing at 2.1%, I think that a population of 200,000 might occur in about the year 2040.
WHEELER: You mentioned that there is additional information you want to get in front of local government, and that you want to gather public feedback about their reactions. What do you think are some of the policy implications that local officials will have to wrestle with?
: We think the community should be debating three issues.
Just because we don’t have satisfactory answers to the second two questions doesn’t mean we shouldn’t try to answer the first question. We may not find answers to the second two questions unless we take the first question pretty seriously. If we decide to avoid growing to the point where our ecosystems are destroyed, our quality of life changes, our taxes are jacked up….If we say we don’t want that, then I have a feeling that this very progressive, well educated, thoughtful community, can come up with the mechanisms, with the number (or range) at which to stop, and the mechanisms to do it.
WHEELER: Some of ASAP’s critics over the years have said that you do want to identify a cap on population in this community. Is that a goal of ASAP?
: Yes. Of course it’s a goal. It should to be a goal for the whole community. And we are leading the charge. We don’t pretend to know what it is yet. That’s the second question that I just raised of the three.
We have a definitive answer to the first question. Should we continue to grow endlessly or identify an optimal sustainable size? The answer to that, ASAP argues, is [that we identify an optimal population size]. The second question is, what is that right size? We don’t at this point know, and that is one reasons we launched these research projects to help us identify it.
WHEELER: Has any other community in the country done this?
: In the press release, we say it is a groundbreaking study. No other community in the United States is undertaking this kind of research to get a sense of its biological carrying capacity.
WHEELER: Why do you think that is?
: This is an idea whose time has come. More and more communities are recognizing that smart growth, while good, ain’t enough and that we’ve got to go beyond it and that communities need to identify the point at which they want to stop. Our children’s children’s children will be irate if we don’t deal with this growth problem. We will have failed future generations if we don’t deal with local as well as global population growth.
WHEELER: Some of the policy implications we might think about in this community include potentially downzoning rural areas, downzoning growth areas, water supply… are there others that you think about?
: Yes there are, but first let me go back to water supply. ASAP believes that we should not be using water supply as a limit to growth. What our community should do is define an optimal population size and then provide the water for that population. But we shouldn’t limit growth by limiting water.
Yes there are other [policy] mechanisms. Conservation easements, the County’s Acquisition of Conservation Easements (ACE) program, and we should look more seriously at the
transfer of development rights
. But until we take the need to cap growth more seriously, we are going to dither about transfer of development rights, as happened in a series of
WHEELER: I want to go back to water and you clarified that it was not the position of ASAP to use the water supply debate happening in the community as a way to limit growth, or that you would build a water plan that resulted in limiting growth. We talked about the trend in population, and if the current trend continues, by 2040 we will have 200,000 people. That is a number your research says maintains ecosystems. Supporters of the current water supply plan, who are trying to plan for a fifty-year time horizon, might look at this research and say we know 200,000 people now is a sustainable population number, should we plan to have enough water for at least that many people during the next fifty years.
: You are trying to push me into a corner I don’t want to be pushed into, but yes that may well be one of the implications. I have a feeling all sides of this water plan debate will find something in here to glom on to. If the community makes a firm decision that we will make every effort to stop growth at 200,000, then yes our water supply should be aimed at that, and our schools, and our roads, and the whole infrastructure and we don’t have to build for a population of 300,000. I think it would solve a lot of problems. It would help decision makers make more wise decisions about how much commercial growth we need, for example, to me the needs of 200,000 people.
WHEELER: I laid out one argument that supporters of the water supply plan might take out of this report. Thinking about those concerned about growth, and there seem to be a growing number of people in the community, when they talk about the water supply plan, saying they don’t want to support growth in Albemarle County. Is there something in this report or in ASAP’s position about this research that you think, some people that might say even 200,000 people is too many, how might you reconcile the research with some of those views in the community?
: This is the first of what we hope will be a whole raft of studies and its purpose is not to provide unequivocal answers to the kinds of questions you are asking, but to start to provide some facts where before we’ve had only had opinions about growth. We need to know what growth means. What will it cost us environmentally, fiscally? What does it mean for the quality of life, for the character of our community?
I know I have friends who think we are already overpopulated, that the 135,000 we have now is far too many. I have other friends who think that 400,000 is nifty, and maybe even more. A lot of it is going to be subjective opinion, but that should be informed by facts about the impacts of more or fewer people here.
WHEELER: Where do you go next with this research?
: We have four other interesting studies in this first phase to help us understand the biological carrying capacity. The other really big one is a look at our community’s ecological footprint. Other studies will look at the impacts of population growth on groundwater resources, air quality, and stream health. After we give these reports to the Board of Supervisors, we will launch into a second phase that looks at the socioeconomic issues in helping us better understand what the growth means for quality of life and our taxes.
WHEELER: When do you expect the first phase to be done and the second phase to start?
: In the next few weeks. All the remaining reports are in the works and we expect them to appear within weeks, and we will as soon as we can after that launch the second phase. Simultaneously with the second phase we will have an outreach community dialogue… and we will be working with the Institute for Environmental Negotiation to take the results of these studies into the community.