Circular utilization of urban tree waste contributes to the mitigation of climate change and eutrophication

•A multi-scale LCA explores the pathways of utilizing urban tree waste in US•Utilizing can yield nationwide environmental benefits US•Highlighting needs to move from landfilling and combusting valuable utilization•Environmental have geospatial variations at state city levels More than 45 million dry tonnes are generated every year US. Landfilling these wastes generates greenhouse gas emissions that contribute climate change nutrient-related causing eutrophication results water crises such as harmful algal boom fish kills. Converting into products help mitigate eutrophication, but it is important understanding extent which reusing reduces impacts. We find converting compost, lumber, chips, biochar substantially national compared with waste. Such vary by location within US, most environmentally beneficial combination using merchantable logs for lumber residues biochar. Our highlight feasibility recycling/reusing wastes. Substantial underutilized Circular utilization has been explored literature, life-cycle implications varied not fully understood. Here we quantify process, state, Full produce global warming potential (127.4–251.8 Mt CO2 eq./year) (93.9–192.7 kt N landfilling. state-level locations due availability types. Process-level comparisons identify The mitigation different circular pathways, supporting development bioeconomy environment. Urban forest, a vital component system, provides many both human natural systems, including temperature microclimatic modification, pollution mitigation, noise reduction, biodiversity habitat enhancement, recreational opportunities.1Nowak D.J. Dwyer J.F. Understanding costs forest ecosystems.in: Kuser J.E. community forestry northeast. Springer, 2007: 25-46Crossref Google Scholar, 2Zhang Z. Meerow S. Newell J.P. Lindquist M. Enhancing landscape connectivity through multifunctional green infrastructure corridor modeling design.Urban For. Green. 2019; 38: 305-317Crossref Scopus (101) 3Speak A. Escobedo F.J. Russo Zerbe Total carbon storage management estimated LiDAR, field measurements an end-of-life wood approach.J. Clean. Prod. 2020; 256: 120420Crossref (17) 4Zhang Stevenson K.T. Martin K.L. Exploring geographical, curricular, demographic factors nature use children schoolyards Raleigh, NC, USA.Urban 2021; 65: 127323Crossref (3) 5Dümpelmann trees times crisis: palliatives, mitigators, resources.One Earth. 2: 402-404Abstract Text PDF PubMed (5) Scholar also crucial source biomass.6Timilsina N. Staudhammer C.L. Lawrence Tree biomass, yield, changes forest.Landsc. Plann. 2014; 127: 18-27Crossref (47) US hold over 800 metric tons (Mt) on ? 51.5 hectares land.7Nowak Greenfield E.J. Ash R.M. Annual biomass loss value United States. for.Urban 46: 126469Crossref (20) Scholar,8Nowak statistics, values, projections.J. 2018; 116: 164-177Google Each year, deciduous trees, or yard maintenance, land clearing, removal (e.g., mortality, windstorms, pests).6Timilsina 25 oven (ODMT) leaf 20 ODMT per equating more mass.7Nowak used, being landfilled (potentially high methane emissions), burned (immediate release biogenic CO2), left site.7Nowak Scholar,9Safford H. Larry E. McPherson E.G. Nowak Westphal L.M. Forests Climate Change. USDA Forest Service, 2013https://www.fs.usda.gov/ccrc/topics/urban-forestsGoogle Scholar,10U.S. Environmental Protection AgencyYard trimmings: Material-specific data.https://www.epa.gov/facts-and-figures-about-materials-waste-and-recycling/yard-trimmings-material-specific-dataDate: 2020Google There increasing interest exploring economically pathways.3Speak Scholar,6Timilsina Scholar,11Araújo Y.R.V. de Góis M.L. Junior L.M.C. Carvalho Carbon footprint associated four disposal scenarios pruning waste.Environ. Sci. Pollut. Res. Int. 25: 1863-1868Crossref (29) Scholar,12Carvalho Araújo M.L.d. Coelho waste: energy generation prospects clean mechanisms.Rev. Árvore. 43: 1-11Crossref (7) For example, et al. economic producing firewood, pallets ($89–$786 million/year, depending combinations products).7Nowak Other studies discussed mitigating reducing be sinks replace materials burdens.9Safford Scholar,13Geological Survey U.S. Removal fallen leaves improve quality.https://www.usgs.gov/news/removal-fallen-leaves-can-improve-urban-water-qualityDate: 2016Google Different exist waste, each pathway critical large-scale sustainable implementation industrial-urban symbiosis.7Nowak Scholar,14Dong Ohnishi Fujita T. Geng Y. Fujii Dong L. Achieving emission reduction industrial & symbiosis: case Kawasaki.Energy. 64: 277-286Crossref (91) Scholar,15Fujii Lu C. Behera S.K. Park H.S. Chiu A.S.F. Possibility developing low-carbon industries symbiosis Asian cities.J. 2016; 114: 376-386Crossref (55) Several evaluated waste.3Speak Scholar,16Nicese F.P. Colangelo G. Comolli R. Azzini Lucchetti Marziliano P.A. Sanesi Estimating balance Life Cycle Assessment prism: – study park.Urban 57: 126869Crossref Most them quantified forests landfill incineration).3Speak However, few systematically made counterpart virgin materials. variabilities throughout life cycle waste-derived virgin-material-based affect diverse previously. Furthermore, previous rarely considered counterfactual cases application) affecting balances emissions. address those research gaps cradle-to-grave assessment (LCA) integrating process Monte Carlo simulation (MCS). This aims tackle question what managing various pathways. To answer this question, chose mulch, electricity, They were selected based their literature.7Nowak Scholar,17Lan K. Kelley S.S. Nepal P. Yao Dynamic analysis cross-laminated timber Southeastern States.Environ. Lett. 15: 124036Crossref (19) 18Lan Ou Kwon Cai fast pyrolysis biofuel produced pine residues: temporal effects.Biotechnol. Biofuels. 14: 191-217Crossref (6) 19Sahoo Bilek Bergman Mani Techno-economic solid biofuels portable systems.Appl. Energy. 235: 578-590Crossref (87) 20Martínez-Blanco J. Lazcano Christensen T.H. Muñoz Rieradevall Møller Antón Boldrin Compost agriculture assessment. A review.Agron. Sustain. Dev. 2013; 33: 721-732Crossref (133) 21Pergola Persiani Palese A.M. Di Meo V. Pastore D’Adamo Celano Composting: way agriculture.Appl. Soil Ecol. 123: 744-750Crossref (79) standardized widely accepted tool evaluate impacts product service its cycle.17Lan Scholar,22Huang B. Gao X. Xu Song Sarkis Fishman Kua Nakatani thinking framework impact building materials.One 3: 564-573Abstract 23Kuempel C.D. Frazier Nash Jacobsen N.S. Williams D.R. Blanchard J.L. Cottrell R.S. McIntyre P.B. Moran D. Bouwman al.Integrating assessments map food’s cumulative footprint.One 65-78Abstract (9) 24Cucurachi Scherer Guinée Tukker food systems.One 1: 292-297Abstract (38) 25Lan technologies under concentration pathways.Environ. Technol. 2022; 56: 1395-1404Crossref 26Liao Lan Sustainability artificial intelligence chemical industry: conceptual framework.J. Ind. 26: 164-182Crossref explore benefits, systems alternative considered. landfill, incineration, mulch represent current treatment methods waste). explored, substitutions included (i.e., mineral fertilizers, grid-purchased chips wood, charcoal soil amendment). All developed commercially available proven technologies.17Lan Scholar,27USDA N.R.C.S. Chapter 2 composting.in: Part 637 Engineering National Handbook. NRCS ed., 2010: 1-61Google Scholar,28Liao Generating inventory data activated production machine learning kinetic simulation.ACS Chem. Eng. 8: 1252-1261Crossref (30) contributes providing process-based models (LCI) pathway. These parametric, used other researchers practitioners types operational conditions. stakeholders policymakers further presented tailor strategies policy toward In study, system boundary includes raw material extraction, production, transportation, end life. coupled LCA. provided LCI mass balances, emissions) composting, manufacturing chips), pyrolysis. allow investigating parameter composition, conversion operations, life) LCI. run MCS, random samples parameters statistical characteristics (determined literature data), inputs results. Since two major challenges related literature,11Araújo Scholar,29Suthar Gairola Nutrient recovery litter solids Eisenia fetida.Ecol. 71: 660-666Crossref (37) Scholar,30Hobbie S.E. Baker L.A. Buyarski Nidzgorski Finlay J.C. Decomposition pavement: quality.Urban Ecosyst. 17: 369-385Crossref focuses indicators: (GWP) potential. GWP standard indicator measure “how much 1 ton will absorb given period time, relative dioxide (CO2).”31US EPAUnderstanding potentials.https://www.epa.gov/ghgemissions/understanding-global-warming-potentialsDate: 2021Google It LCAs (GHG) emissions.17Lan Scholar,18Lan Scholar,32Lan Integrating agent-based modeling: dynamic agricultural systems.J. 238: 117853Crossref Eutrophication phenomenon nutrient enrichment aquatic ecosystems common category Tool Reduction Chemicals Impacts [TRACI], ReCiPe).31US Scholar,33Bare Traci 2.0: 2.0. Clean Technol.Clean Environ. Policy. 2011; 13: 687-696Crossref (453) Scholar,34Goedkoop Heijungs Huijbregts Schryver A.D. Struijs Zelm R.V. ReCiPe 2008 Impact Method Which Comprises Harmonised Category Indicators Midpoint Endpoint Level.2009Google categorized three groups sizes, logs, residues. Removed stem diameters larger 22.9 cm (9.0 inches) softwood 27.9 (11.0 hardwood classified trees. parts production. rest removed smaller non-merchantable trees.7Nowak branches, limbs, needles17Lan Scholar) five established understand processing (see section “scenario analysis”, Table 1, Figure 5 details). Scenarios sustainability guideline Department Agriculture (USDA) Service.35Leff Sustainable Step-by-step Approach. Davey Institute/USDA utilization. ranked low utilization, while fair Reusing recycling energy, products, purposes beyond good Comprehensive all suggested optimal Based guideline, was scenario baseline 2–4 designed options mentioned (by incineration), products. Specifically, incinerates power generation, still landfilled. 3, collected compost organic fertilizer replaces fertilizers nitrogen, phosphorus, potassium fertilizers), incinerated. 4, composted, chipped serve practice.36Stai S.M. Wiseman P.E. Fernholz Wood Utilization Virginia, North Carolina, Georgia: Comparison Industry Practices Perceptions.2017Google details described “methodology.” Scenario where turned mulch. Previous identified viable products,7Nowak Scholar,37Bratkovich Bowyer Lindburg Why Matters. DOVETAIL PARTNERS, INC., 2008Google Scholar,38Kuser Community Forestry Northeast. 2007Crossref only limited large enough salable sawlogs pulpwood.39USDA Service Glossary engineering terms.https://www.srs.fs.usda.gov/forestops/glossary/Date: residues, negative technology combat change.40National Academies Sciences MedicineNegative Emissions Technologies Reliable Sequestration: Research Agenda. Press, 2019Google Biochar amendment shows stability soil. 80% retained medium even after 100 years cropland grassland applications.18Lan Scholar,41IPCCBuendia E.C. Tanabe Kranjc Baasansuren Fukuda Ngarize Osako Pyrozhenko Shermanau Federici IPCC 2019 Refinement 2006 Guidelines Greenhouse Gas Inventories. IPCC, Hence, stable long-term pool.42Smith sequestration technologies.Glob. Chang. Biol. 22: 1315-1324Crossref (435) Urban-tree-waste-derived substitute traditional charcoal, substitution effects. suitable applications ash content.7Nowak Scholar,43Heckman J.R. Kluchinski Chemical composition municipal hand-collected litter.J. Qual. 1996; 355-362Crossref (42) 44Nurmatov Leon Gomez Hensgen F. Bühle Wachendorf High-quality fuel street trees.Sustainability. 1249Crossref 45Piepenschneider Nurmatov properties slagging fuels litter.Waste Biomass Valorization. 7: 625-633Crossref (11) Therefore, matches utilizations: utilized converted substitutes charcoal. Not US;10U.S. Scholar,35Leff