Carbon removals from nature restoration are no substitute for steep emission reductions

•A “responsible development” approach to nature restoration minimizes land-use change•We assess the responsible potential for land removals at 103 GtC over century•Land cannot be scaled up quickly enough noticeably reduce peak global temperatures•Nature is crucial but offset fossil fuel emissions net zero Growing commitments net-zero by 2050 achieve Paris Agreement goals are a welcome step forward on climate action have also seen an increasing focus remove carbon dioxide from atmosphere. This risks over-relying mitigation expense of phasing out fuels. At same time, wide range activities being labeled “nature restoration,” some which, such as monoculture tree plantations, degrade nature—destroying biodiversity, pollution, and removing food production. We apply framing imagine constrained restoration, guided ecological principles. Quantifying resultant uptake temperature impacts shows that can marginally lower warming, any benefits dwarfed scale ongoing emissions. conclude more “zero” less “net” required targets. The role in mitigating change receiving attention, yet often assessed terms removal rather than ability meet goals, those outlined Agreement. Here, we estimate framework contribution this would make 1.5°C limit. Our options result median (5%–95% −91 196 GtC) cumulative between 2020 2100. When combined with deep-decarbonization scenarios, our scenario briefly exceeds before declining 1.25°C 2100 (median, 50% probability). additional sequestration via unlikely done notably temperatures expected next few decades. Land important option tackling compensate delays reducing atmospheric carbon-dioxide (CDR) growing area research, Intergovernmental Panel Climate Change (IPCC) Special Report has confirmed level CDR will essential limiting warming 1.5°C, or even below 2°C, above pre-industrial levels.1Riahi K. Schaeffer R. Arango J. Calvin Guivarch C. Hasegawa T. Jiang Kriegler E. Matthews Peters G.P. et al.Mitigation pathways compatible long-term goals.in: 2022: change. Change, 2022https://www.ipcc.ch/report/ar6/wg3/Google Scholar Even most ambitious decarbonization rely (lower) levels CDR.2Grubler A. Wilson Bento N. Boza-Kiss B. Krey V. McCollum D.L. Rao N.D. Riahi Rogelj De Stercke S. al.A low energy demand meeting 1.5 °C target sustainable development without negative emission technologies.Nat. Energy. 2018; 3: 515-527https://doi.org/10.1038/s41560-018-0172-6Crossref Scopus (437) Google Yet reliant significant change, bioenergy capture storage (BECCS) afforestation reforestation (AR), remain predominant integrated assessment modeling climate-policy debates.3Dooley Christoff P. Nicholas K.A. Co-producing policy emissions: Trade-offs land-use.Glob. Sustain. 1: e3https://doi.org/10.1017/sus.2018.6Crossref (25) Scholar,4Workman M. Darch G. Dooley Lomax Maltby Pollitt H. decision making contexts deep uncertainty - From optimisation robustness.Environ. Sci. Pol. 2021; 120: 127-137https://doi.org/10.1016/j.envsci.2021.03.002Crossref (7) Research so far focused techno-economic acceptability framings feasibility sufficient consideration environmental social extensive While broader concerns beginning reflected literature, delivering future scenarios,5O’Neill D.W. Fanning A.L. Lamb W.F. Steinberger J.K. A good life all within planetary boundaries.Nat. 88-95https://doi.org/10.1038/s41893-018-0021-4Crossref (537) Scholar, 6Soergel Weindl I. Rauner Dirnaichner Ruhe Hofmann Bauer Bertram Bodirsky B.L. pathway UN 2030 Agenda.Nat. Clim. Change. 11: 656-664https://doi.org/10.1038/s41558-021-01098-3Crossref (32) 7Motesharrei Rivas Kalnay Asrar G.R. Busalacchi A.J. Cahalan R.F. Cane M.A. Colwell R.R. Feng Franklin R.S. al.Modeling sustainability: Population, inequality, consumption, bidirectional coupling Earth human systems.Natl. Rev. 2016; 470-494https://doi.org/10.1093/nsr/nww081Crossref PubMed (92) AR still included uncritically differentiating strong co-benefits could cause livelihoods, security. concept one not only considers sustainability constraints attends consequences may targets Agreement.8Waller L. Rayner Chilvers Gough C.A. Lorenzoni Jordan Vaughan Contested greenhouse gas its feasibility: Social political dimensions.WIREs Clim 2020; e649https://doi.org/10.1002/wcc.649Crossref (27) Doing requires examining contestations alternative approaches mitigation, which turn bring fore value judgements conflicts represented 1.5°C. concern heavy reliance relates large part BECCS change,3Dooley Scholar,8Waller well what been referred “mitigation deterrence,” whereby expectations delay replace near-term reductions.9McLaren D.P. Tyfield Willis Szerszynski Markusson N.O. Beyond “net-zero”: case separate reduction emissions.Front. 2019; 4https://doi.org/10.3389/fclim.2019.00004Crossref (59) recent studies sought understand upper bounds restoration,10Bastin J.-F. Finegold Y. Garcia Mollicone D. Rezende Routh Zohner C.M. Crowther T.W. potential.Science. 365: 76-79https://doi.org/10.1126/science.aax0848Crossref (674) 11Erb K.-H. Kastner Plutzar Bais A.L.S. Carvalhais Fetzel Gingrich Haberl Lauk Niedertscheider al.Unexpectedly impact forest management grazing vegetation biomass.Nature. 553: 73-76https://doi.org/10.1038/nature25138Crossref (258) 12Walker W.S. Gorelik S.R. Cook-Patton S.C. Baccini Farina M.K. Solvik K.K. Ellis P.W. Sanderman Houghton R.A. Leavitt S.M. al.The increased land.Proc. Natl. Acad. USA. 2022; 119 (e2111312119)https://doi.org/10.1073/pnas.2111312119Crossref (1) here call “responsible” go beyond avoiding urban agricultural areas base then demonstrate century. study goes existing literature assesses restoration13Matthews H.D. Zickfeld Dickau MacIsaac Mathesius Nzotungicimpaye C.-M. Luers Temporary nature-based well-below 2 scenario.Commun. Environ. 65https://doi.org/10.1038/s43247-022-00391-zCrossref (4) interrogating options. do restore degraded lands forests other AR, distinction rarely made literature. On basis distinction, develop five land-management ecosystem (beyond countries pledged) while assessing (to extent pledged). matters because therefore presents trade-offs restoring maintaining uses. suggest combination maximum land-restoration available contribute mitigation. potential, century-long reduction. Given healthy ecosystems critical combating change,14Lade S.J. Norberg Anderies J.M. Beer Cornell S.E. Donges J.F. Fetzer Gasser Richardson Rockström Steffen W. Potential feedbacks loss biosphere integrity change.Glob. 2: e21https://doi.org/10.1017/sus.2019.18Crossref principles guide interventions inherently beneficial—to climate, people—thereby building resilience capacity.15Stefanes Ochoa-Quintero Roque F.D.O. Sugai L.S.M. Tambosi L.R. Lourival Laurance Incorporating cost strategies landscape scale.E&S. 21: 54https://doi.org/10.5751/es-08922-210454Crossref 16Lewis S.L. Wheeler C.E. Mitchard E.T.A. Koch Restoring natural best way carbon.Nature. 568: 25-28https://doi.org/10.1038/d41586-019-01026-8Crossref (274) 17Seddon Turner Berry Chausson Girardin C.A.J. Grounding solutions sound biodiversity science.Nat. 9: 84-87https://doi.org/10.1038/s41558-019-0405-0Crossref (96) simplistic typology these key characteristics depicted Table 1, used selection represent different restoration. These primary objective (restoration production), intervention (land-use land-cover production intensity), integrity.Table 1Land-use pathwaysPrimary useManagement interventionPathwayImproved integrityrestorationland-use changeforest (from productive use allowing secondary reach their biological potential)land-cover changereforestation deforested forested regeneration)productionreduced productionreduced harvest (reduced logging intensity) silvopasture intensity)increased productivityagroforestry (increased crop productivity) (alternative feed sources) Open table new tab carbon-sequestration aim (which refer ECORES) quantified area-based estimates flux (details provided experimental procedures). peatland, coastal, marine among dense world, scale, coastal orders magnitude terrestrial ecosystems,18Hoegh-Guldberg O. Northrop Lubchenco ocean achieving societal goals.Science. 1372-1374https://doi.org/10.1126/science.aaz4390Crossref (37) peatland results (significant) avoided sequestration.19Leifeld Menichetti underappreciated peatlands strategies.Nat. Commun. 1071https://doi.org/10.1038/s41467-018-03406-6Crossref (235) For reasons, study, although baseline summarized Tables S2–S7). present combining (the RESTORE scenario). (ECORES) build previous work Teske al.20Teske Achieving Goals: Global Regional 100% Renewable Energy Scenarios Non-energy GHG Pathways +1.5°C +2°C. Springer, 2019Crossref (91) Littleton al.21Littleton E.W. Webb Harper A.B. Powell Nicholls Z. Meinshausen Lenton T.M. Dynamic modelling substantial mitigation.Environ. Res. Lett. 16: 124061https://doi.org/10.1088/1748-9326/ac3c6cCrossref (2) using updated datasets extending analysis studies.Table 2Five (ECORES)PathwayDescriptionForested landsforest restorationset aside (secondary) conservation purposes; biomes (1,893 Mha 25% forests)reduced harvestreduction intensity temperate boreal managed (221 19%) ceasing industrial tropical (532 remaining 75%)reforestationreforestation mixed-native species biomes; maintained purposes 211 pledged under Bonn Challenge 2021 here)Agricultural landsagroforestryintegrating trees croplands 20% (278 Mha)silvopastureincreased shrubs 10% pastureland (308 Mha) reduced show gross ECORES Gt (GtC) annual rate (forest reforestation, harvest, agroforestry, silvopasture) 2.6 per year 1–5 year), 1 decades (Figure 1). average 1.2 year. canceled emissions, discussed section “temperature pathways.” approximately higher found when were modeled dynamic model (DGVM); difference largely due inclusion soil response DGVM.21Littleton However, given very methodological quantifying removal, similarity increases confidence results. Figure scales disturbances see jump after 20-year implementation period. During period, regrowth considered non-additional. include 20 years, factors old apply.22Harris N.L. Gibbs D.A. Birdsey de Bruin Fatoyinbo Hansen M.C. Herold al.Global maps twenty-first century fluxes.Nat. 234-240https://doi.org/10.1038/s41558-020-00976-6Crossref (121) All implemented regions, two harvest) region. highest confined region uncertainties forests.22Harris Scholar,23Gibbs Harris Forest factor variance domain (1.2.0) [Dataset].2021https://doi.org/10.5281/zenodo.5537134Crossref consistent understanding land-based efforts remains highly uncertain,24Krause Pugh T.A.M. Bayer A.D. Li Leung F. Bondeau Doelman J.C. Humpenöder Anthoni al.Large climate-change efforts.Global Biol. 24: 3025-3038https://doi.org/10.1111/gcb.14144Crossref component uncertain budget, particularly regarding land-carbon northern latitudes.25Friedlingstein Jones M.W. O’Sullivan Andrew R.M. Bakker D.C.E. Hauck Le Quéré Pongratz budget 2021.Earth Syst. Data. 14: 1917-2005https://doi.org/10.5194/essd-2021-386Crossref find rates tropics. full recovering stocks forests,22Harris it consider benefit (see below). based current pledges,26The Challengehttps://www.bonnchallenge.orgGoogle around 5% regions (and none boreal), meaning majority occurs unlike pledges, assume reforested diversity native thereafter standing stocks. Analysis reality half pledges commercial plantations.16Lewis timber plantations much 90% storage,16Lewis significantly idealized assumptions. similar removal. similarities both disturbance forests, greater area, resulting changed management, allows recovery carrying capacity one-quarter (removing proportion areas). Reduced hand, represents intensity, research suggests allow increase time continues.27Pingoud Ekholm Sievänen Huuskonen Hynynen harvests steady state – multi-criteria analysis.J. Manag. 210: 96-103https://doi.org/10.1016/j.jenvman.2017.12.076Crossref 28Law B.E. Hudiburg Berner L.T. Kent J.J. Buotte P.C. Harmon M.E. mitigate forests.Proc. 115: 3663-3668https://doi.org/10.1073/pnas.1720064115Crossref (120) 29Roxburgh S.H. Wood S.W. Mackey B.G. Woldendorp Gibbons Assessing forests: Australia: potential.J. Appl. Ecol. 2006; 43: 1149-1159https://doi.org/10.1111/j.1365-2664.2006.01221.xCrossref (82) apparent there evidence continues decline harvest.11Erb Scholar,30Luyssaert Schulze E.-D. Börner Knohl Hessenmöller Law Ciais Grace Old-growth sinks.Nature. 2008; 455: 213-215https://doi.org/10.1038/nature07276Crossref (1117) 31Orihuela-Belmonte D.E. Jong B.H.J. Mendoza-Vega Van der Wal Paz-Pellat Soto-Pinto Flamenco-Sandoval Carbon accumulation community, type.Agric. Ecosyst. 2013; 171: 72-84https://doi.org/10.1016/j.agee.2013.03.012Crossref (47) 32Lutz J.A. Furniss T.J. Johnson D.J. Davies Allen Alonso Anderson-Teixeira K.J. Andrade Baltzer Becker K.M.L. importance large-diameter trees.Global Biogeogr. 27: 849-864https://doi.org/10.1111/geb.12747Crossref (200) 33Stephenson Das Condit Russo Baker P.J. Beckman N.G. Coomes Lines E.R. Morris W.K. Rüger al.Rate continuously size.Nature. 2014; 507: 90-93https://doi.org/10.1038/nature12914Crossref (510) Hence, presented here, no they allowed manner pathway. harvested wood products (HWPs) excluded sensitivity suggesting overestimated.34Harmon Have product substitution overestimated? assumptions.Environ. 065008https://doi.org/10.1088/1748-9326/ab1e95Crossref (33) Reducing provides immediate degradation, quantify 0.03 according 35% density through degradation.35Mackey Kormos C.F. Keith Moomaw W.R. Mittermeier Hole Hugh Understanding protection strategy.Mitig. Adapt. Strategies Glob. 25: 763-787https://doi.org/10.1007/s11027-019-09891-4Crossref (36) representing areas—agroforestry silvopasture—allow uses continue. Agroforestry many ways, assumed integration into landscapes, across croplands. Silvopasture—a complex intensively system trees, forage plants, livestock—has shown storage, sometimes commensurate landscapes.36Murphy B.P. Andersen A.N. Parr C.L. underestimated grassy biomes.Phil. Trans. 371: 20150319https://doi.org/10.1098/rstb.2015.0319Crossref (71) Scholar,37Jose Dollinger Silvopasture: livestock system.Agrofor. 93: 1-9https://doi.org/10.1007/s10457-019-00366-8Crossref (63) total ECORES—a addition activities—is 2. end middle estimated ranges (approximately 30–217 GtC),38Nolan C.J. Field C.B. Mach Constraints enablers biosphere.Nat. 436-446https://doi.org/10.1038/s43017-021-00166-8Crossref (10) reflecting conservativeness double counting minimizing regional differences relate primarily climatic biome already above. Higher Asia, Latin America, Africa, where productivity. Greater tropics predominantly located countries. biomes, was entirely halted tropics, contributor regions. projections, reduced-complexity probabilistic emulator reflects science line IPCC