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- ItemTaking stock of national climate policies to evaluate implementation of the Paris Agreement([London] : Nature Publishing Group UK, 2020) Roelfsema, Mark; van Soest, Heleen L.; Harmsen, Mathijs; van Vuuren, Detlef P.; Bertram, Christoph; den Elzen, Michel; Höhne, Niklas; Iacobuta, Gabriela; Krey, Volker; Kriegler, Elmar; Luderer, Gunnar; Riahi, Keywan; Ueckerdt, Falko; Després, Jacques; Drouet, Laurent; Emmerling, Johannes; Frank, Stefan; Fricko, Oliver; Gidden, Matthew; Humpenöder, Florian; Huppmann, Daniel; Fujimori, Shinichiro; Fragkiadakis, Kostas; Gi, Keii; Keramidas, Kimon; Köberle, Alexandre C.; Aleluia Reis, Lara; Rochedo, Pedro; Schaeffer, Roberto; Oshiro, Ken; Vrontisi, Zoi; Chen, Wenying; Iyer, Gokul C.; Edmonds, Jae; Kannavou, Maria; Jiang, Kejun; Mathur, Ritu; Safonov, George; Vishwanathan, Saritha SudharmmaMany countries have implemented national climate policies to accomplish pledged Nationally Determined Contributions and to contribute to the temperature objectives of the Paris Agreement on climate change. In 2023, the global stocktake will assess the combined effort of countries. Here, based on a public policy database and a multi-model scenario analysis, we show that implementation of current policies leaves a median emission gap of 22.4 to 28.2 GtCO2eq by 2030 with the optimal pathways to implement the well below 2 °C and 1.5 °C Paris goals. If Nationally Determined Contributions would be fully implemented, this gap would be reduced by a third. Interestingly, the countries evaluated were found to not achieve their pledged contributions with implemented policies (implementation gap), or to have an ambition gap with optimal pathways towards well below 2 °C. This shows that all countries would need to accelerate the implementation of policies for renewable technologies, while efficiency improvements are especially important in emerging countries and fossil-fuel-dependent countries.
- ItemAmbiguity in the Land Use Component of Mitigation Contributions Toward the Paris Agreement Goals(Hoboken, NJ : Wiley-Blackwell, 2019) Fyson, C.L.; Jeffery, M.L.Land use, land use change, and forestry (LULUCF) activities, including deforestation and forest restoration, will play an important role in addressing climate change. Countries have stated their contributions to reducing emissions and enhancing sinks in their Nationally Determined Contributions (NDCs); in 2023, the Global Stocktake will assess the collective impact of these NDCs. Clarity in the contribution of LULUCF to NDC targets is necessary to prevent high LULUCF uncertainties from undermining the strength and clarity of mitigation in other sectors. We assess and categorize all 167 NDCs and find wide variation in how they incorporate LULUCF; many lack the clear information necessary to understand what land-based mitigation is anticipated. The land sector is included in 121 NDCs, but only 11 provide a LULUCF target that can be fully quantified using information presented or referenced in the NDC. By developing alternative scenarios from a subset of 62 NDCs (89 countries), we estimate that ambiguity in LULUCF contributions causes an uncertainty range in the anticipated LULUCF sink in 2030 of magnitude 2.9 GtCO2eq/year—larger in size than our best estimate for the LULUCF sink of −2 GtCO2eq/year. Clearer communication of data sources and assumptions underlying the contribution of land use to mitigation efforts is therefore important for ensuring a robust Global Stocktake and ambitious emissions reductions. We find that guidance under the Paris Agreement may improve the clarity of future NDCs but is not sufficient to eliminate ambiguities. We therefore recommend that LULUCF targets should be presented and accounted for separately from other sectors. ©2019. The Authors.
- ItemBioenergy production and sustainable development: Science base for policymaking remains limited(Milton Park : Taylor & Francis, 2016) Robledo‐Abad, Carmenza; Althaus, Hans‐Jörg; Berndes, Göran; Bolwig, Simon; Corbera, Esteve; Creutzig, Felix; Garcia‐Ulloa, John; Geddes, Anna; Gregg, Jay S.; Haberl, Helmut; Hanger, Susanne; Harper, Richard J.; Hunsberger, Carol; Larsen, Rasmus K.; Lauk, Christian; Leitner, Stefan; Lilliestam, Johan; Lotze‐Campen, Hermann; Muys, Bart; Nordborg, Maria; Ölund, Maria; Orlowsky, Boris; Popp, Alexander; Portugal‐Pereira, Joana; Reinhard, Jürgen; Scheiffle, Lena; Smith, PeteThe possibility of using bioenergy as a climate change mitigation measure has sparked a discussion of whether and how bioenergy production contributes to sustainable development. We undertook a systematic review of the scientific literature to illuminate this relationship and found a limited scientific basis for policymaking. Our results indicate that knowledge on the sustainable development impacts of bioenergy production is concentrated in a few well‐studied countries, focuses on environmental and economic impacts, and mostly relates to dedicated agricultural biomass plantations. The scope and methodological approaches in studies differ widely and only a small share of the studies sufficiently reports on context and/or baseline conditions, which makes it difficult to get a general understanding of the attribution of impacts. Nevertheless, we identified regional patterns of positive or negative impacts for all categories – environmental, economic, institutional, social and technological. In general, economic and technological impacts were more frequently reported as positive, while social and environmental impacts were more frequently reported as negative (with the exception of impacts on direct substitution of GHG emission from fossil fuel). More focused and transparent research is needed to validate these patterns and develop a strong science underpinning for establishing policies and governance agreements that prevent/mitigate negative and promote positive impacts from bioenergy production.
- ItemRealizing Mitigation Efficiency of European Commercial Forests by Climate Smart Forestry(London : Nature Publishing Group, 2018) Yousefpour, R.; Augustynczik, A.L.D.; Reyer, C.P.O.; Lasch-Born, P.; Suckow, F.; Hanewinkel, M.European temperate and boreal forests sequester up to 12% of Europe's annual carbon emissions. Forest carbon density can be manipulated through management to maximize its climate mitigation potential, and fast-growing tree species may contribute the most to Climate Smart Forestry (CSF) compared to slow-growing hardwoods. This type of CSF takes into account not only forest resource potentials in sequestering carbon, but also the economic impact of regional forest products and discounts both variables over time. We used the process-based forest model 4 C to simulate European commercial forests' growth conditions and coupled it with an optimization algorithm to simulate the implementation of CSF for 18 European countries encompassing 68.3 million ha of forest (42.4% of total EU-28 forest area). We found a European CSF policy that could sequester 7.3-11.1 billion tons of carbon, projected to be worth 103 to 141 billion euros in the 21st century. An efficient CSF policy would allocate carbon sequestration to European countries with a lower wood price, lower labor costs, high harvest costs, or a mixture thereof to increase its economic efficiency. This policy prioritized the allocation of mitigation efforts to northern, eastern and central European countries and favored fast growing conifers Picea abies and Pinus sylvestris to broadleaves Fagus sylvatica and Quercus species.
- ItemWe need biosphere stewardship that protects carbon sinks and builds resilience(Washington, DC : National Acad. of Sciences, 2021) Rockström, Johan; Beringer, Tim; Hole, David; Griscom, Bronson; Mascia, Michael B.; Folke, Carl; Creutzig, Felix[no abstract available]