Terrestrial Carbon Dioxide Removal (tcdr) A. Popp and many others 30 January 2017
Long history of MIPs for Integrated Assessment and Energy Models established at Stanford in 1976 to improve understanding of critical energy problems 21 Multigas Mitigation and Climate Change first time many climate economic and IAMs included non-co2 greenhouse gas mitigation options, as well as forest carbon sequestration mitigation options. 27 Global Model Comparison Exercise on individual mitigation options including bioenergy. 33 Bioenergy and land use - ongoing
MAgPIE - Model of Agricultural Production and ist Impacts on the Environment
Displacement effects
Full accounting of water flows within agriculture Estimating change in water scarcity Blue water withdrawal to availabilility ratio
Full accounting of nitrogen flows within agriculture
Full accounting of carbon flows Carbon stocks CO2 emissions Soil Litter Vegetation
Today mainly 2 (t) CDR options in the models
PIAM Potsdam Integrated Assessment Modelling Framework Bioenergy demand Bioenergy yields Bioenergy prices
GHG price Carbon density Growth curve
Figure from Bodirsky and Popp, Nature 2015
Biomass provision as an important ESS for climate change mitigation CDR is a key element of most 1.5 /2 C transformation pathways. CDR with huge impact on the land system. Reference case RCP2.6 no mitigation SSP5 bioenergy crops SSP5 fossil fueled development Based on Riahi et al et al 2017 GEC; Rose, Popp et al. 2014, Climatic Change; Popp et al. 2017, GEC
Externalities of land-use Loss of natural land Greenhouse gas emissions from land use and agricultural production Nitrogen pollution Water withdrawals for irrigation Loss of biodiversity Food security
Approach in MAgPIE for assessing side-effects of tcdr Exogeneous demand, GHG prices, CDR pathways MAgPIE Land requirements Biodiversity Water withdrawals Food prices
Different efficiencies and land requirements of BECCS & Afforestation Hunpenöder et al. 2016 BECCS more efficient in terms of C sequestration per area
Co-emissions from bioenergy production Based on Popp et al. 2011, Ecological Economics; Popp et al. 2012 Biomas & Bioenergy
Serious consequence for food prices due to increased competition for land
Water withdrawals due to BECCS Bonsch et al. 2016 Large-scale bioenergy cultivation may put substantial pressure on land and water resources Critical as many regions already face water scarcity and freshwater ecosystems are degraded by human activity
Conclusion & Outlook tcdr can have consequences for other environemental, social and economic sustainability criteria Need for holistic strategies to align tcdr with a broader sustainability agenda. Need for improved understanding of consequences (e.g. food prices vs food security). Full portfolio CDR assessment needed. Other terrestrial (non-land demanding) tcdr options to be assessed in the future (such as SCM, biochar, agroforestry, wetlands).
SOC flow in agricultural practice land conversion choice of crop, intensity and rotation, fertilizer and nutrients, mixed systems harvest/residue management tillage irrigation (paddy rice) increase SOC decrease SOC organic amentments (manure, biochar, legume, compost) soil (organic carbon) decomposition erosion
Conclusion & Outlook tcdr can have consequences for other environemental, social and economic sustainability criteria Need for holistic strategies to align tcdr with a broader sustainability agenda. Need for improved understanding of consequences (e.g. food prices vs food security). Full portfolio CDR assessment needed. Other terrestrial (non-land demanding) tcdr options to be assessed in the future (such as SCM, biochar, agroforestry, wetlands). Successful implementation of tcdr futures requires early action due to time lags in implementation of environmental protection measures, R&D realization, behavioral changes. Take care of land - most straightforward strategy to limit potential tradeoffs between tcdr options and other SDGs is of course to decrease GHG emissions early in time.
Many thanks for your attention! popp@pik-potsdam.de