This is a story of two cities located within 100 miles of each other in Colorado, in that paradise created by close mountain recreation, clean and clear western vistas, and local, great universities. The question is, does this story tell a tale of urban growth that mistakenly shows up as global warming, or is it a story of wise planning that avoids the harms of global warming — or something else in between, or completely different?
Boulder, Colorado at twilight, at the foot of the Rockies – Wikipedia Image by Phil Armitage
Anthony Watts complained that I don’t read his blog closely enough, or often enough. He may rue the day he made that complaint.
Browsing over there I found a post hidden under a headline, “A UHI Tale of Two Cities.” I say “hidden” because Watts once again falls victim to the Dunning-Kruger syndrome of using an acronym, UHI, which sounds sciency but is in fact confusing to anyone not following the debate closely. I’m science literate, I’ve done research, I’ve done air pollution research, I’ve served state, federal and local governmental bodies working on environmental issues, and “UHI” didn’t ring any bells with me. It’s a MEGO phrase, in other words: My Eyes Glaze Over.
It took five clicks, but I discovered UHI is “urban heat island,” the well-worried-over effect of cities, with all their concrete, asphalt and steel, holding heat longer than surrounding countryside. In some cases, it is hypothesized that these urban heat islands affect or create their own weather. In the airline industry we worried about late afternoon thunderstorms that continued well past historical evening limits (and I suspect airline meteorologists and flight schedulers still worry about the issue, but I’ve been out of it for well over a decade).
For the study of global warming, the issues are simple but important: Do temperature measures made in or near big cities inaccurately show warming that is wholly local, and mislead scientists into thinking there is global warming? Or is some of the supposed heat island effect instead due to global warming? And, if it the urban heat island effect is mostly local, should we worry about it when developing policies to combat global warming and preserve our forests, wildlands and wildlife, wildernesses. oceans, rivers, farmlands and urban areas, and modern life?
Southwest quadrant of Boulder Colorado, showing greenbelt and trails – image from city website with information on greenbelt use and open space regulations, and maps. Boulder’s greenbelt open space and wild lands may get more visitors than nearby Rocky Mountain National Park.
In the post at Watts’s site, this is stated (from Watts? from someone else? Who can tell?):
Conclusion:
We have two weather stations in similarly sited urban environments. Until 1965 they tracked each other very closely. Since then, Fort Collins has seen a relative increase in temperature which tracks the relative increase in population. UHI is clearly not dead.
Watts misses much of the story.
In the middle 1960s and into the early 1970s Boulder, Colorado, made conscious and careful attempts to preserve its environmental quality. In 1967 Boulder created a greenbelt plan that started the processes to preserve an open space belt around the city, to preserve wild lands and to provide a sink for air pollutants and other effects of the city. In the early 1970s the city limited city growth to assure environmental quality.
Alternatives to Growth Oregon (AGO) featured an excerpt from a book detailing several growth-controlling actions by American cities as well and succinctly as anything else I’ve found (excerpted from Better Not Bigger by Eben Fodor)
In 1967, Boulder voters approved one of the nation’s first locally funded greenbelt systems. They used a local sales tax increase of 0.4 percent to finance open space land acquisitions. As of 1998, Boulder had raised $116 million and acquired 33,000 acres of greenways and mountain parks. The greenbelt system serves as a natural growth boundary, defining the limits of the city with open space and parkland. This natural boundary helps to block urban sprawl and “leapfrog” development. The greenbelt has also helped protect the quality of life in Boulder as the city has grown. It is said that more people use the greenbelt system each year than visit nearby Rocky Mountain National Park. As an added measure, Boulder established a building height limitation of 55 feet in 1971 to preserve the view of the Rockies. The city and surrounding county have cooperated on planning and growth-management policies and jointly adopted the Boulder Valley Comprehensive Plan. A city-county study in 1970 showed the area’s population doubling in 20 years to 140,000. This projection alarmed many residents and prompted discussions about optimum population size. A public opinion survey found that more than 70 percent of respondents favored population stabilization near the 100,000 level.
In November, 1971 Boulder citizens set another first when they placed an initiative on the ballot to create a charter amendment setting a maximum population limit for the city. Voters narrowly defeated the initiative. The defeat may have been partly due to an alternative referendum placed on the same ballot by the city council. This second referendum was approved by 70 percent of voters and directed local government to “take steps necessary to hold the rate of growth in the Boulder Valley to a level substantially below that experiences in the 1960’s.” This important decision has led to a number of experimental growth-management policies that are still being fine-tuned today.
More information on greenbelts, how they work and why they are such a great idea, can be found from the Trust for Public Lands (also here), among other sources.
Fort Collins is a college town, like Boulder, and loaded with people interested in preserving the environment. Colorado State is the state’s Land Grant College (Morrill Act), the official repository of studies of protecting and wisely using the lands of Colorado. But Fort Collins did not create a green belt. Development in Fort Collins follows rules, but rules set by more traditional zoning and protection regulations than Boulder’s green belt.
Exploring Old Town Fort Collins by bicycle – City of Fort Collins photo
Watts’s blog lays the differences in temperatures between Boulder and Fort Collins since 1965 entirely at the feet of rising population, and an assumption that rising population means more concrete, asphalt and steel (Watts writing, or someone else?). Analysis of population growth from any serious statistical viewpoint, comparing Fort Collins-Loveland SMSA against the Boulder MSA (or Denver-Boulder SMSA) is lacking. This is probably more a reminder that Watts’s blog is not engaged in serious scientific analysis global warming from a global view — nor even a national, state or regional view. The comparison is simple, on population and temperature, and probably not sustainable to the point Watts suggests he wants to take it.
The population of the City of Boulder grew less than the population of the City of Fort Collins grew. That appears to be enough for Watts.
Check with the public officials of Boulder, especially those in charge of development and zoning. They’ll let you know in a hurry that Boulder’s slower-than-Fort-Collins growth is intentional. While the Boulder plan technically has no upper limit, it slows growth so that environmental quality can be maintained, especially the greenbelt, with its manifold recreation opportunities.
Fort Collins has a lot of good recreation, too. The Cache de Poudre River offers great river running within 40 minutes of downtown in the summer, and the local National Forests and other public lands offer camping, hiking, hunting, fishing, and I imagine, snowmobiling in winter. There are bike paths through Fort Collins — but not the green, automobile-free style of trails available all around Boulder.
Scouts climbing at Camp Ben DelaTour, outside of Fort Collins – Longs Peak Council BSA photo
Perhaps most important, Fort Collins experiences “leapfrog” development that Boulder specifically spurned 40 years ago. New businesses cluster along roads into town, frequently just out of the city limits and beyond the zoning rules of the city, at least until the city annexes the land and its problems. This is the traditional growth model for American cities. What it ensures is urban sprawl and suburban growth. It also virtually guarantees that there will be no preserved greenlands around the city. Green land, rural or more wild, get developed in sprawl.
Here’s the question Watts and his collaborators don’t deal with: How much of Boulder’s cooler climate is due to the greenbelt, and how much due to the striving for wise development instead of sprawl? Considering Boulder’s proximity to Denver and explosive growth there, the fact that Boulder’s climate is cooler than Fort Collins’s, according to Watts, suggests even more strongly that tough protection of the environment can work wonders, if not near-miracles.
Who is Anthony Watts to claim that Boulder’s cooler climate is not the result of careful planning to preserve the environment, initiated by Boulder’s visionaries 50 years ago?
Perhaps more critically: Doesn’t Boulder demonstrate that planning that stops global warming, is feasible, practical, economical, and perhaps, preferable? Doesn’t the greenbelt, and lower temperatures, suggest that we can kill the urban heat island effect, to the betterment of local living standards?
There is a moral to the story of development in Fort Collins and Boulder, Colorado. That moral has very little, if anything, to do with heat islands. It is instead a model to tell us that planning to avoid environmental disaster is the wise thing to do. Anthony Watts has the charts to prove it.
Notes:
- A serious study of the effects of the greenbelt, or effects of population growth, on local climate, or on global warming, in the area along the Front Range in Colorado and Wyoming would probably be strengthened with analysis of Greeley and Denver thrown in. Denver is big enough to contain a couple of universities; Greeley is home to Northern Colorado University (as Fort Collins and Boulder are homes to Colorado State and the University of Colorado, respectively). Growth in Greeley, a prairie, farming and beef ranching town (and former utopian destination of easterners headed west), differs markedly from Fort Collins, founded as a military outpost to protect the Overland Trail and other commerce routes through the Rockies, and Boulder, largely a mining town. Similarities and differences between the cities could be instructive, especially considering the proximity of each to the others.
- Boulder gets its water from a glacier, a point that shouldn’t be lost in discussions of global warming
- City of Boulder’s officials and advisors, and Copenhagen 15 — the city took what it regarded as an active role to combat warming
- Watts visited Boulder to check out its weather stations; his photos show the station, near the NOAA headquarters, close to the green belt. “Sometimes people smack into the truth, and then pick themselves up and walk off as if nothing had happened.” Watts said construction near the site demonstrated “expansion pressures.”
- From Boulder, it’s 38 miles to Fort Collins, and 38 miles to Greeley. Greeley and Fort Collins are 19 miles apart. From Denver it’s 26 miles to Boulder, 47 to Greeley and 55 to Fort Collins.
- Two-needled ponderosa pines live outside of Fort Collins, to the northwest. Most pines have odd numbers of needles, and ponderosa typically have five needles.
Update, James Madison Day (3-16-2010): Watts still doesn’t get it. In a post today he wrote:
My last few posts have described a new method for quantifying the average Urban Heat Island (UHI) warming effect as a function of population density, using thousands of pairs of temperature measuring stations within 150 km of each other. The results supported previous work which had shown that UHI warming increases logarithmically with population, with the greatest rate of warming occurring at the lowest population densities as population density increases.
Comparing Fort Collins with Boulder, and noting that Fort Collins grew faster, is an inadequate explanation for more warming in Fort Collins, about 40 miles north of Boulder. Boulder has a greenbelt designed to frustrate global warming, locally and globally. To fail to account for the effect of a massive green belt of 33,000 acres — more than double the size of the city’s 16,000 acres — is a failure of science. If Watts’s methodology misses such factors that slap an unbiased viewer in the face, you’ve gotta wonder what else he’s missing. If he can’t see a greenbelt twice the size of the city, surrounding the city, what else has he overlooked?
Plus there is this: Assume for a moment that he proves a heat island effect exists (a proposal unquestioned in meteorology and atmospheric sciences for a generation, by the way) — the question he’s seeking to prove is that urban heat islands skew official temperature readings enough to falsely indicate global warming. To skew measurements that include thousands of at-sea sensing devices, and rural areas around the world, there would have to be an massive effect that would be immediately obvious in the cities causing the effect: They would melt.
Flatirons rock formations, on Green Mountain, near Boulder, Colorado – Wikimedia photo by Jesse Varner
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Posted by Ed Darrell 
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