Meg+Lawler+Draft

Meg Lawler's Draft Page

Meg's Goal For Class: -Have 3rd paper completed and ready to defend on March 24th.

ABSTRACT: It has been suggested that municipal biomass residue (MBR) in the Southern U.S. could be used to generate electricity thus reducing fossil fuel consumption. One form of MBR is yard wastes, which is currently transformed into landscape mulch in most Southern communities. This study modeled CO2 emissions associated with the landscape mulch practice and contrasted them to a hypothetical practice of burning the waste to produce electricity. A 1.28% reduction of CO2 was seen in the hypothetical practice. We discuss implication for reallocating urban forest wastes. We conclude that exclusive use of MBR is not feasible or sustainable for the long term. <<george - Good story, but these last two sentences need changed. INstead of saying "we discuss" you should list the key implications. You might also want to back up why it's not feasible with a sentence or two. LIKE you said orally ... Using biomass residue will not, by itself, significantly reduce CO2 emissions. Further, the practice is likely not a sustainable long-term practices because (1) most of the waste comes from permanent removal of forest for buildings; (2) the demand for mulch will be satisfied in other ways that might generate more CO2 than the reduction documented here, etc ... Significant reductions in CO2 emissions will also require energy conservation ... ANYWAY, this isn't worded quite right, but just a thought on maybe how to handle.>>

__**OUTLINE:**__ INTRO:
 * Paragraph 1: Why MBR and Renewable energy is of current interest & importance
 * RPS, Climate Change, GHG etc.
 * Paragraph 2: Why renewable energy doesn't automatically mean reduced CO2 emissions
 * Arguments for electricity generated from urban wood residues lack empirical evidence illustrating potential effects on CO2 emissions
 * Paragraph 3: The scope of this study was to evaluate the CO2 emissions associated with utilizing MBR to generate electricity in North Carolina, the first southern state to adopt RPS
 * Objective 1: Estimate CO2 emissions associated with Production of Landscape Mulch in Wake County 2008
 * Objective 2: Estimate CO2 emissions associated with co-firing of coal & wood chips
 * Objective 3: Compare estimates from objectives 1 & 2 and discuss in terms of regional scale
 * These results are critical to investors and managers as they make decisions that have the potential to impact markets, policies, and ultimately the future sustainability of their communities.
 * These results are critical to investors and managers as they make decisions that have the potential to impact markets, policies, and ultimately the future sustainability of their communities.

METHODS:
 * Data Sources
 * Wake County Urban Yard Wastes LCID
 * Data Analysis
 * (Objective 1) Mulch Model: Et = εM + Ce + Rm
 * (Objective 2) Hog Fuel Model Eh = εH + H0 + C0 + Rh.
 * (Objective 3) ΔE = Et - Eh (HELP me extend this to regional scale!)

RESULTS: <>
 * Total emissions from the mulch scenario were Et = 70,999,775.58 Mt CO2
 * total emissions from the hog fuel scenario were Eh = 70,962,760.42 Mt CO2
 * The difference between emissions from the two scenarios was ΔE = 7,994.52 Mt CO2.

DISCUSSION:

This is Kevin's suggestion for the discussion: P1 - CO2 emissions decreased using hog method, which jives with RPS literature but there is some concern over the source of the MBR.

P2 - 80% actually comes from large scale land modification - clearing, not yard waste.

P3 - Focus on the 20% here

P4 - The urban environment is devoid of resources... start with these sentences - For example, carbon emissions aside, urban soil health is compromised due to anthropogenic influences on the carbon cycle. Similarly, it has been suggested that burning urban wood waste may reduce a significant long term carbon storage pool and therefore limit reducing atmospheric CO2 levels (MacFarlane, 2009). AND then go into the best way you think this 20% should be used.

P5 - talk about LCAs, maybe give an example of how your best use of the 20% might turn out to be a bad idea.

P6 - maybe here is where you talk about cities as emitters of CO2 and how what you are doing barely helps, but that it does help and that it can also help build stronger community relations and educate folks or something (I'm just making up stuff now).

P? - <> talk about the things you do not consider, gas for cars, mowers, leaf-blower, etc. and how that might screw up the model.

DRAFT INTRODUCTION: I The adoption of Renewable Portfolio Standards (RPS) by twenty-seven states and the District of Columbia (U.S. DOE, 2010), has increased interest in the conversion of wood-waste to electricity as a means of reducing fossil fuel consumption. Municipal biomass residues (MBR) in the Southern U.S. promise an abundance of renewable fuel feedstocks (Mayfield et al., 2007 ; Gregg, 2010). Urban feedstocks are appealing to investors due to their inherent proximity to processing facilities (Aguilar, 2009). In addition to arguments advocating the market potential of urban wood utilization, evidence suggests that residents would support alternative waste-wood management strategies (Lawler Unpublished Data, 2010). As one of four long-lasting anthropogenic greenhouse gas emissions (GHG) carbon dioxide (CO2) contributes to climate change and therefore CO2 reductions are necessary if impacts to humans are to be avoided, reduced or delayed (Pachauri and Reisinger, 2007, Solomon et al., 2007). Shifting to a socially acceptable and economically promising renewable energy does not necessarily affect a city’s total CO2 footprint. Trees in urban areas store carbon, but more CO2 is emitted from human practices than can be sequestered by the urban forest. Regulations which establish standards for bioenergy use (U.S. DOE, 2010) and literature discussing options for meeting those standards (Abt et al., 2010; Hazel and Bardon, 2008; Rich, 2010) assume that increasing the use of renewable fuels will decrease carbon emissions (Giampietro et al., 1997). Arguments for electricity generated from urban wood residues lack empirical evidence illustrating potential effects on CO2 emissions. Other urban forest management strategies have produced such evidence; for example, the ability of trees to reduce energy demands along with the overall urban heat island effect (McPherson and Rowntree, 1993; McPherson and Simpson, 2003; Simpson and McPherson, 1996; Simpson and McPherson, 1998), which further reduces energy consumption and the CO2 emissions associated with that energy. Likewise, strategically placed shade trees have been shown to reduce energy consumed in the summer for cooling (Donovan and Butry, 2009). One study suggests that ultimately a greater reduction in CO2 emissions is seen from energy conservation than from tree plantings (McPherson et al., 1994). These and other studies have shown that greater reductions in CO2 emissions are achieved by managing biomass for the purpose of reducing CO2, rather than managing biomass for the purpose of reducing fossil fuel use (Gustavsson et al., 2007). The flow of carbon should be considered alongside economics, social acceptability and policy compliance, to determine management strategies and renewable energy feedstocks that reduce CO2 emissions. The scope of this study was to evaluate the CO2 emissions associated with utilizing MBR to generate electricity in North Carolina, the first southern state to adopt RPS (Abt et al., 2010). We compared two potential uses of MBR from urban forest maintenance and urban development (commonly known as yard wastes) in Wake County, NC. We considered the scenario as it occurred in 2008, where all recorded yard wastes were processed into landscape mulch. The results from this scenario were contrasted against a hypothetical scenario in which hog fuel (a common term for wood chips that are burned to generate electricity) was created from all of the recorded yard wastes. As we expected, we calculated less CO2 emitted in the hog fuel scenario than the mulch scenario, due to inherent differences in processing. Despite this finding our analysis suggests it is not feasible, in the long run, to decrease CO2 emissions exclusively by managing MBR for hog fuel rather than for mulch. These results are critical to investors and managers as they make decisions that have the potential to impact markets, policies, and ultimately the future sustainability of their communities.