Amidst the woefully ignorant din and clamor of the anti-environmentalists in Congress feverishly working to strip our nation's environmental laws and protections for the sake of these representatives' business bidders and masters, it was heartening and enlightening to learn about the results of a series of studies first begun in the mid-nineties and carried on for several years later.
The initial question poised for the study was: "Don't trees clean the air?," asked by the then- current mayor of Chicago, Richard M. Daley, Jr., in 1989. A series of other questions followed such as: "What is the character of an American urban forest? How did trees interact with the ecosystem? Do they really affect air quality?" Daley started an ambitious tree-planting program at that time but wanting to find some answers as well, he obtained federal funding for a study progam through the efforts of long-time North Shore representative Sidney R. Yates (D-Ill). The first fruits of this study was titled "The Chicago Urban Forest Climate Project." Several facts were revealed including: the Chicago metro area's urban forest contained roughly 51 million trees, two-thirds of which were in "good or excellent condition." And, in Chicago, the street trees made up only a tenth of the urban forest, buy they provided a quarter of the tree canopy. And, the canopy shaded only 11 percent of the city, less than half of the proportion city officials believed was ideal (Jonnes, Jill, The Wilson Quarterly, Winter 2011, p. 38).
A panapoly of other facts emerged from the study: in 1991, trees in Chicago removed an estimated 17 tons of carbon monoxide, 93 tons of sulfur dioxide, 98 tons of nitrogen dioxide, 210 tons of ozone, and 234 tons of particulate matter. And that's not counting the 155,000 tons of carbon dioxide that our trees in Chicago sequestered a year. Sad to say, that impressive amount accounts only for the tons of carbon put out by motor vehicles in the Chicago area during one week. But, as the author notes, "over time, the urban forest could sequester as much as eight times more carbon if the city planted greater numbers of large, long-lived species such as oaks or London planes and actively nurtured existing trees to full maturity." She states that a large tree that lives on for many decades or even a couple of centuries is able to "sequester a thousand times more carbon than, say, a crab apple with a life span of 10 or 20 years."
Regrettably, Mayor Daley did not whole-heartedly adopt the implications of this groundbreaking report. He supported the planting of trees in the city but not in the larger-scaled, strategic manner that the report recommended. Nevertheless, his support pushed forward in a big way the study of trees and their public health implications for urban areas and the citizens who live in these areas. In 993, the Sacramento Municipal Utility did a large-scale assessment study after it had planted 110,000 trees in the front yards of residential customers for free. Among other things, the study found that "a tree planted to the west of a house saved about three times more energy ($120 versus $39) in a year than the same kind of tree planted to the south." The utility's shade program "collectively saves the utility from having to supply $1.2 million worth of electricity annually (_39).
In 2006, in New York City, the Parks Department asked the original study's authors to assess the value of all of the city's 592,000 street trees. The lead authors, by this time, had significantly more sophisticated data tools on hand, and were able to determine for the department that the city's street trees delivered an annual energy savings of roughly $28 million, or $47. 63 per tree. The researchers then calculated multiple other parameters such as savings to stormwater systems through the trees' interception of rainwater ($35.6 million annually); removal of air pollutants ($5 million annually); and a host of other compounding factors such as: hospital patients who could see a tree out of their room were discharged a day earlier than others who could not; shopping areas with trees had more customers than areas that did not; public-housing projects that had leafy tree areas suffered less violence than bare, tree-less projects, and so forth. Together these assessments and findings delivered a summary value of $122 million per year in savings to New York City, or about $209 per tree. This is truly amazing, both for the value that our trees serve up and for the data-finding abilities of these reports. These findings offer a promising potential to turn the minds and mindsets of those radical extremists who are frothing at the bit to remove environmental protections, to dismiss out of hand any efforts to establish a mutually-beneficial relationship with the environment that supplies us with pretty much all of our essential needs. All they do is to chant the jobs mantra. Well, how many jobs do they really think they are going to create as they tear up our nation's national parks, devastate through pollution our nation's rivers, lakes, and streams, and clog our nation's air with mercury, particulates, sulfur dioxide and all the other pestilences? And what kind of variety in jobs do they promise? And at what kind of salaries?
The data from these studies add significant support to the contentions and calls for a positive, supportive approach to our environment as we continue to draw out from it the natural resources that we require, and also over-require through greed and very high expectations for our quality of life. Thanks for reading my blog. I hope you will gain something valuable and important from this.
Note: The authors of these studies along with other professionals have come up with a free software progam called i-Tree which now has the ability to quantify the monetary benefits of any urban tree in America.
