@article{SoergelKrieglerWeindletal.2021, author = {Soergel, Bjoern and Kriegler, Elmar and Weindl, Isabelle and Rauner, Sebastian and Dirnaichner, Alois and Ruhe, Constantin and Hofmann, Matthias and Bauer, Nico and Bertram, Christoph and Bodirsky, Benjamin Leon and Leimbach, Marian and Leininger, Julia and Levesque, Antoine and Luderer, Gunnar and Pehl, Michaja and Wingens, Christopher and Baumstark, Lavinia and Beier, Felicitas and Dietrich, Jan Philipp and Humpen{\"o}der, Florian and von Jeetze, Patrick and Klein, David and Koch, Johannes and Pietzcker, Robert C. and Strefler, Jessica and Lotze-Campen, Hermann and Popp, Alexander}, title = {A sustainable development pathway for climate action within the UN 2030 Agenda}, series = {Nature climate change}, volume = {11}, journal = {Nature climate change}, number = {8}, publisher = {Nature Publishing Group}, address = {London}, issn = {1758-678X}, doi = {10.1038/s41558-021-01098-3}, pages = {656 -- 664}, year = {2021}, abstract = {Ambitious climate policies, as well as economic development, education, technological progress and less resource-intensive lifestyles, are crucial elements for progress towards the UN Sustainable Development Goals (SDGs). However, using an integrated modelling framework covering 56 indicators or proxies across all 17 SDGs, we show that they are insufficient to reach the targets. An additional sustainable development package, including international climate finance, progressive redistribution of carbon pricing revenues, sufficient and healthy nutrition and improved access to modern energy, enables a more comprehensive sustainable development pathway. We quantify climate and SDG outcomes, showing that these interventions substantially boost progress towards many aspects of the UN Agenda 2030 and simultaneously facilitate reaching ambitious climate targets. Nonetheless, several important gaps remain; for example, with respect to the eradication of extreme poverty (180 million people remaining in 2030). These gaps can be closed by 2050 for many SDGs while also respecting the 1.5 °C target and several other planetary boundaries.}, language = {en} } @article{vanSoestAleluiaReisBaptistaetal.2021, author = {van Soest, Heleen L. and Aleluia Reis, Lara and Baptista, Luiz Bernardo and Bertram, Christoph and Despr{\´e}s, Jacques and Drouet, Laurent and den Elzen, Michel and Fragkos, Panagiotis and Fricko, Oliver and Fujimori, Shinichiro and Grant, Neil and Harmsen, Mathijs and Iyer, Gokul and Keramidas, Kimon and K{\"o}berle, Alexandre C. and Kriegler, Elmar and Malik, Aman and Mittal, Shivika and Oshiro, Ken and Riahi, Keywan and Roelfsema, Mark and van Ruijven, Bas and Schaeffer, Roberto and Silva Herran, Diego and Tavoni, Massimo and {\"U}nl{\"u}, Gamze and Vandyck, Toon and van Vuuren, Detlef P.}, title = {Global roll-out of comprehensive policy measures may aid in bridging emissions gap}, series = {Nature communications}, volume = {12}, journal = {Nature communications}, number = {1}, publisher = {Nature Publishing Group UK}, address = {London}, doi = {10.1038/s41467-021-26595-z}, pages = {10}, year = {2021}, abstract = {Closing the emissions gap between Nationally Determined Contributions (NDCs) and the global emissions levels needed to achieve the Paris Agreement's climate goals will require a comprehensive package of policy measures. National and sectoral policies can help fill the gap, but success stories in one country cannot be automatically replicated in other countries. They need to be adapted to the local context. Here, we develop a new Bridge scenario based on nationally relevant, short-term measures informed by interactions with country experts. These good practice policies are rolled out globally between now and 2030 and combined with carbon pricing thereafter. We implement this scenario with an ensemble of global integrated assessment models. We show that the Bridge scenario closes two-thirds of the emissions gap between NDC and 2 °C scenarios by 2030 and enables a pathway in line with the 2 °C goal when combined with the necessary long-term changes, i.e. more comprehensive pricing measures after 2030. The Bridge scenario leads to a scale-up of renewable energy (reaching 52\%-88\% of global electricity supply by 2050), electrification of end-uses, efficiency improvements in energy demand sectors, and enhanced afforestation and reforestation. Our analysis suggests that early action via good-practice policies is less costly than a delay in global climate cooperation.}, language = {en} } @article{StreflerKrieglerBaueretal.2021, author = {Strefler, Jessica and Kriegler, Elmar and Bauer, Nico and Luderer, Gunnar and Pietzcker, Robert C. and Giannousakis, Anastasis and Edenhofer, Ottmar}, title = {Alternative carbon price trajectories can avoid excessive carbon removal}, series = {Nature communications}, volume = {12}, journal = {Nature communications}, number = {1}, publisher = {Nature Publishing Group}, address = {London}, issn = {2041-1723}, doi = {10.1038/s41467-021-22211-2}, pages = {8}, year = {2021}, abstract = {The large majority of climate change mitigation scenarios that hold warming below 2 °C show high deployment of carbon dioxide removal (CDR), resulting in a peak-and-decline behavior in global temperature. This is driven by the assumption of an exponentially increasing carbon price trajectory which is perceived to be economically optimal for meeting a carbon budget. However, this optimality relies on the assumption that a finite carbon budget associated with a temperature target is filled up steadily over time. The availability of net carbon removals invalidates this assumption and therefore a different carbon price trajectory should be chosen. We show how the optimal carbon price path for remaining well below 2 °C limits CDR demand and analyze requirements for constructing alternatives, which may be easier to implement in reality. We show that warming can be held at well below 2 °C at much lower long-term economic effort and lower CDR deployment and therefore lower risks if carbon prices are high enough in the beginning to ensure target compliance, but increase at a lower rate after carbon neutrality has been reached.}, language = {en} } @article{LudererMadedduMerfortetal.2021, author = {Luderer, Gunnar and Madeddu, Silvia and Merfort, Leon and Ueckerdt, Falko and Pehl, Michaja and Pietzcker, Robert C. and Rottoli, Marianna and Schreyer, Felix and Bauer, Nico and Baumstark, Lavinia and Bertram, Christoph and Dirnaichner, Alois and Humpen{\"o}der, Florian and Levesque, Antoine and Popp, Alexander and Rodrigues, Renato and Strefler, Jessica and Kriegler, Elmar}, title = {Impact of declining renewable energy costs on electrification in low-emission scenarios}, series = {Nature energy}, volume = {7}, journal = {Nature energy}, number = {1}, publisher = {Nature Publishing Group}, address = {London}, issn = {2058-7546}, doi = {10.1038/s41560-021-00937-z}, pages = {32 -- 42}, year = {2021}, abstract = {Cost degression in photovoltaics, wind-power and battery storage has been faster than previously anticipated. In the future, climate policy to limit global warming to 1.5-2 °C will make carbon-based fuels increasingly scarce and expensive. Here we show that further progress in solar- and wind-power technology along with carbon pricing to reach the Paris Climate targets could make electricity cheaper than carbon-based fuels. In combination with demand-side innovation, for instance in e-mobility and heat pumps, this is likely to induce a fundamental transformation of energy systems towards a dominance of electricity-based end uses. In a 1.5 °C scenario with limited availability of bioenergy and carbon dioxide removal, electricity could account for 66\% of final energy by mid-century, three times the current levels and substantially higher than in previous climate policy scenarios assessed by the Intergovernmental Panel on Climate Change. The lower production of bioenergy in our high-electrification scenarios markedly reduces energy-related land and water requirements.}, language = {en} } @article{MerfortBauerHumpenoederetal.2023, author = {Merfort, Leon and Bauer, Nico and Humpen{\"o}der, Florian and Klein, David and Strefler, Jessica and Popp, Alexander and Luderer, Gunnar and Kriegler, Elmar}, title = {Bioenergy-induced land-use-change emissions with sectorally fragmented policies}, series = {Nature climate change}, volume = {13}, journal = {Nature climate change}, number = {7}, publisher = {Nature Publ. Group}, address = {London}, issn = {1758-678X}, doi = {10.1038/s41558-023-01697-2}, pages = {685 -- 692}, year = {2023}, abstract = {Controlling bioenergy-induced land-use-change emissions is key to exploiting bioenergy for climate change mitigation. However, the effect of different land-use and energy sector policies on specific bioenergy emissions has not been studied so far. Using the global integrated assessment model REMIND-MAgPIE, we derive a biofuel emission factor (EF) for different policy frameworks. We find that a uniform price on emissions from both sectors keeps biofuel emissions at 12 kg CO2 GJ-1. However, without land-use regulation, the EF increases substantially (64 kg CO2 GJ-1 over 80 years, 92 kg CO2 GJ-1 over 30 years). We also find that comprehensive coverage (>90\%) of carbon-rich land areas worldwide is key to containing land-use emissions. Pricing emissions indirectly on the level of bioenergy consumption reduces total emissions by cutting bioenergy demand but fails to reduce the average EF. In the absence of comprehensive and timely land-use regulation, bioenergy thus may contribute less to climate change mitigation than assumed previously.}, language = {en} } @article{MerfortBauerHumpenoederetal.2023, author = {Merfort, Leon and Bauer, Nico and Humpen{\"o}der, Florian and Klein, David and Strefler, Jessica and Popp, Alexander and Luderer, Gunnar and Kriegler, Elmar}, title = {State of global land regulation inadequate to control biofuel land-use-change emissions}, series = {Nature climate change}, volume = {13}, journal = {Nature climate change}, number = {7}, publisher = {Nature Publ. Group}, address = {London}, issn = {1758-678X}, doi = {10.1038/s41558-023-01711-7}, pages = {610 -- 612}, year = {2023}, abstract = {Under current land-use regulation, carbon dioxide emissions from biofuel production exceed those from fossil diesel combustion. Therefore, international agreements need to ensure the effective and globally comprehensive protection of natural land before modern bioenergy can effectively contribute to achieving carbon neutrality.}, language = {en} } @article{BersalliTroendleLilliestam2023, author = {Bersalli, Germ{\´a}n and Tr{\"o}ndle, Tim and Lilliestam, Johan}, title = {Most industrialised countries have peaked carbon dioxide emissions during economic crises through strengthened structural change}, series = {Communications earth \& environment}, volume = {4}, journal = {Communications earth \& environment}, number = {1}, publisher = {Springer Nature}, address = {London}, issn = {2662-4435}, doi = {10.1038/s43247-023-00687-8}, pages = {44 -- 44}, year = {2023}, abstract = {As the climate targets tighten and countries are impacted by several crises, understanding how and under which conditions carbon dioxide emissions peak and start declining is gaining importance. We assess the timing of emissions peaks in all major emitters (1965-2019) and the extent to which past economic crises have impacted structural drivers of emissions contributing to emission peaks. We show that in 26 of 28 countries that have peaked emissions, the peak occurred just before or during a recession through the combined effect of lower economic growth (1.5 median percentage points per year) and decreasing energy and/or carbon intensity (0.7) during and after the crisis. In peak-and-decline countries, crises have typically magnified pre-existing improvements in structural change. In non-peaking countries, economic growth was less affected, and structural change effects were weaker or increased emissions. Crises do not automatically trigger peaks but may strengthen ongoing decarbonisation trends through several mechanisms.}, language = {en} }