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C an climate benefits be reconciled with revenues for land management?. Annette Freibauer 1 , Hannes Böttcher 1 , Yvonne Scholz 2 , Vincent Gitz 3 , Philippe Ciais 4 , Martina Mund 1 , Thomas Wutzler 1 , Ernst-Detlef Schulze 1
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Can climate benefits be reconciled with revenues for land management? Annette Freibauer 1, Hannes Böttcher 1, Yvonne Scholz 2, Vincent Gitz 3, Philippe Ciais 4, Martina Mund 1, Thomas Wutzler 1, Ernst-Detlef Schulze 1 1 MPI-BGC Jena; 2 DLR Stuttgart; 3 CIRED - CNRS/EHESS Paris; 4 LSCE Gif-sur-Yvette
Outline • What to optimize? • Case study for forestry and cropland in Central Germany • C stocks • fossil C substitution • Net revenues and C prices • Conclusions
What to optimize? • Reference: functional unit scarcest resource = productive land: hectare • Criteria • climate benefits • net revenue • System boundaries • C stocks on land • C stocks in sector (including products) • holistic life cycle view: fossil C substitution • energy provision • energy embedded in products
Case study: Thuringia • Agriculture • Plains • Rich soils • Forest • Low mountain ranges • Poor soils • Afforestation of cropland • No deforestation
Regional constraints • Forestry • No deforestation • No fertilizer • No stands with exotic trees • Subsidies for old-growth hardwood forests for non-use (FFH) • Agriculture • No C loss from soils • Subsidies: • area-based, independent of product • extra for renewables • Product use • No organic material in landfills: complete waste incineration (assumed: 80%)
Elements of study Original land use Purpose Products Incineration Energy Forest Timber Long-lived products Conservation Short-lived products Recycling / reuse Cropland Decay on site Afforestation Food Consumption / Decay Landfill
Cropland: a hectare of cereals • Food only • Food + straw • Set-aside • Annuals • Poplar • Afforestation
Forestry:a hectare of beech or spruce • Land use decisions • Continue timber production • Switch to bioenergy • Sequester carbon on-site: conservation • 3 levels of productivity • 3 levels of accessibility (slope)
C stocks: Timing matters! Trade-off between fast accumulation and large accumulation
Fossil C substitution t fossil-C saved per t bioenergy-C
Climate effects in forestry 311 246 262 Spruce for products Spruce for energy Spruce for sequestration 500 Mean C benefits over 150 years (t C/ha) 311 229 226 Spruce for products Spruce for energy Spruce for sequestration 400 300 C stocks + cumulative C substitution, tC/ha 200 Benefits by recycling 100 C stocks in soil, biomass & products C stocks + substitution 0 time 25 50 75 100 125 Years
Climate effects in cropland Wheat for food Straw for energy Poplar for energy Oak for products 303 153 43 168 500 Mean C stocks (t C/ha) over 150 years 168 98 43 28 Wheat for food Straw for energy First pulp, then energy Poplar for energy Oak for products 400 300 C stocks + cumulative C substitution, tC/ha 200 100 0 time 25 50 75 Years
Forestry: What pays off most? without subsidies with subsidies spruce timber spruce timber + conservation spruce energy spruce energy spruce conservation
Cropland: What pays off most? without subsidies with subsidies poplar poplar food+straw food+straw afforestation afforestation
Concept of maximum climate benefits High Land use priorities Black: Conservation Grey: Forestry White: Agriculture Conservation Land use intensity C sequestration prices Carbon stocks in ecosystem Timber forestry C prices by substitution effectiveness Bioenergy Agriculture Productivity / accessibility High Low
What is best?High C stocks: Conserve themHigh productivity: Use it effectively