Search Results

Now showing 1 - 2 of 2
  • Item
    Impacts devalue the potential of large-scale terrestrial CO2 removal through biomass plantations
    (Bristol : IOP Publishing, 2016) Boysen, L.R.; Lucht, W.; Gerten, D.; Heck, V.
    Large-scale biomass plantations (BPs) are often considered a feasible and safe climate engineering proposal for extracting carbon from the atmosphere and, thereby, reducing global mean temperatures. However, the capacity of such terrestrial carbon dioxide removal (tCDR) strategies and their larger Earth system impacts remain to be comprehensively studied—even more so under higher carbon emissions and progressing climate change. Here, we use a spatially explicit process-based biosphere model to systematically quantify the potentials and trade-offs of a range of BP scenarios dedicated to tCDR, representing different assumptions about which areas are convertible. Based on a moderate CO2 concentration pathway resulting in a global mean warming of 2.5 °C above preindustrial level by the end of this century—similar to the Representative Concentration Pathway (RCP) 4.5—we assume tCDR to be implemented when a warming of 1.5 °C is reached in year 2038. Our results show that BPs can slow down the progression of increasing cumulative carbon in the atmosphere only sufficiently if emissions are reduced simultaneously like in the underlying RCP4.5 trajectory. The potential of tCDR to balance additional, unabated emissions leading towards a business-as-usual pathway alike RCP8.5 is therefore very limited. Furthermore, in the required large-scale applications, these plantations would induce significant trade-offs with food production and biodiversity and exert impacts on forest extent, biogeochemical cycles and biogeophysical properties.
  • Item
    Productivity ranges of sustainable biomass potentials from non-agricultural land
    (Bristol : IOP Publishing, 2016) Schueler, Vivian; Fuss, Sabine; Steckel, Jan Christoph; Weddige, Ulf; Beringer, Tim
    Land is under pressure from a number of demands, including the need for increased supplies of bioenergy. While bioenergy is an important ingredient in many pathways compatible with reaching the 2 °C target, areas where cultivation of the biomass feedstock would be most productive appear to co-host other important ecosystems services. We categorize global geo-data on land availability into productivity deciles, and provide a geographically explicit assessment of potentials that are concurrent with EU sustainability criteria. The deciles unambiguously classify the global productivity range of potential land currently not in agricultural production for biomass cultivation. Results show that 53 exajoule (EJ) sustainable biomass potential are available from 167 million hectares (Mha) with a productivity above 10 tons of dry matter per hectare and year (tD Mha−1 a−1), while additional 33 EJ are available on 264 Mha with yields between 4 and 10 tD M ha−1 a−1: some regions lose less of their highly productive potentials to sustainability concerns than others and regional contributions to bioenergy potentials shift when less productive land is considered. Challenges to limit developments to the exploitation of sustainable potentials arise in Latin America, Africa and Developing Asia, while new opportunities emerge for Transition Economies and OECD countries to cultivate marginal land.