TY - JOUR A1 - Warszawski, Lila A1 - Kriegler, Elmar A1 - Lenton, Timothy M. A1 - Gaffney, Owen A1 - Jacob, Daniela A1 - Klingenfeld, Daniel A1 - Koide, Ryu A1 - Costa, María Máñez A1 - Messner, Dirk A1 - Nakicenovic, Nebojsa A1 - Schellnhuber, Hans Joachim A1 - Schlosser, Peter A1 - Takeuchi, Kazuhiko A1 - van der Leeuw, Sander A1 - Whiteman, Gail A1 - Rockström, Johan T1 - All options, not silver bullets, needed to limit global warming to 1.5 °C BT - a scenario appraisal JF - Environmental research letters N2 - Climate science provides strong evidence of the necessity of limiting global warming to 1.5 °C, in line with the Paris Climate Agreement. The IPCC 1.5 °C special report (SR1.5) presents 414 emissions scenarios modelled for the report, of which around 50 are classified as '1.5 °C scenarios', with no or low temperature overshoot. These emission scenarios differ in their reliance on individual mitigation levers, including reduction of global energy demand, decarbonisation of energy production, development of land-management systems, and the pace and scale of deploying carbon dioxide removal (CDR) technologies. The reliance of 1.5 °C scenarios on these levers needs to be critically assessed in light of the potentials of the relevant technologies and roll-out plans. We use a set of five parameters to bundle and characterise the mitigation levers employed in the SR1.5 1.5 °C scenarios. For each of these levers, we draw on the literature to define 'medium' and 'high' upper bounds that delineate between their 'reasonable', 'challenging' and 'speculative' use by mid century. We do not find any 1.5 °C scenarios that stay within all medium upper bounds on the five mitigation levers. Scenarios most frequently 'over use' CDR with geological storage as a mitigation lever, whilst reductions of energy demand and carbon intensity of energy production are 'over used' less frequently. If we allow mitigation levers to be employed up to our high upper bounds, we are left with 22 of the SR1.5 1.5 °C scenarios with no or low overshoot. The scenarios that fulfil these criteria are characterised by greater coverage of the available mitigation levers than those scenarios that exceed at least one of the high upper bounds. When excluding the two scenarios that exceed the SR1.5 carbon budget for limiting global warming to 1.5 °C, this subset of 1.5 °C scenarios shows a range of 15–22 Gt CO2 (16–22 Gt CO2 interquartile range) for emissions in 2030. For the year of reaching net zero CO2 emissions the range is 2039–2061 (2049–2057 interquartile range). KW - climate change KW - emissions scenarios KW - 1.5 ◦C KW - negative emissions Y1 - 2021 U6 - https://doi.org/10.1088/1748-9326/abfeec SN - 1748-9326 N1 - Corrigendum: 10.1088/1748-9326/acbf6a VL - 16 IS - 6 PB - IOP Publishing CY - Bristol ER - TY - GEN A1 - Lenton, Timothy M. A1 - Rockstroem, Johan A1 - Gaffney, Owen A1 - Rahmstorf, Stefan A1 - Richardson, Katherine A1 - Steffen, Will A1 - Schellnhuber, Hans Joachim T1 - Climate tipping points - too risky to bet against : Comment T2 - Nature : the international weekly journal of science Y1 - 2019 U6 - https://doi.org/10.1038/d41586-019-03595-0 SN - 0028-0836 SN - 1476-4687 VL - 575 IS - 7784 SP - 592 EP - 595 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Sillmann, Jana A1 - Lenton, Timothy M. A1 - Levermann, Anders A1 - Ott, Konrad A1 - Hulme, Mike A1 - Benduhn, Francois A1 - Horton, Joshua B. T1 - COMMENTARY: No emergency argument for climate engineering JF - Nature climate change Y1 - 2015 SN - 1758-678X SN - 1758-6798 VL - 5 IS - 4 SP - 290 EP - 292 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Levermann, Anders A1 - Bamber, Jonathan L. A1 - Drijfhout, Sybren A1 - Ganopolski, Andrey A1 - Haeberli, Winfried A1 - Harris, Neil R. P. A1 - Huss, Matthias A1 - Krueger, Kirstin A1 - Lenton, Timothy M. A1 - Lindsay, Ronald W. A1 - Notz, Dirk A1 - Wadhams, Peter A1 - Weber, Susanne T1 - Potential climatic transitions with profound impact on Europe Review of the current state of six 'tipping elements of the climate system' JF - Climatic change : an interdisciplinary, intern. journal devoted to the description, causes and implications of climatic change N2 - We discuss potential transitions of six climatic subsystems with large-scale impact on Europe, sometimes denoted as tipping elements. These are the ice sheets on Greenland and West Antarctica, the Atlantic thermohaline circulation, Arctic sea ice, Alpine glaciers and northern hemisphere stratospheric ozone. Each system is represented by co-authors actively publishing in the corresponding field. For each subsystem we summarize the mechanism of a potential transition in a warmer climate along with its impact on Europe and assess the likelihood for such a transition based on published scientific literature. As a summary, the 'tipping' potential for each system is provided as a function of global mean temperature increase which required some subjective interpretation of scientific facts by the authors and should be considered as a snapshot of our current understanding. Y1 - 2012 U6 - https://doi.org/10.1007/s10584-011-0126-5 SN - 0165-0009 SN - 1573-1480 VL - 110 IS - 3-4 SP - 845 EP - 878 PB - Springer CY - Dordrecht ER - TY - GEN A1 - Smith, Taylor A1 - Zotta, Ruxandra-Maria A1 - Boulton, Chris A. A1 - Lenton, Timothy M. A1 - Dorigo, Wouter A1 - Boers, Niklas T1 - Reliability of resilience estimation based on multi-instrument time series T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Many widely used observational data sets are comprised of several overlapping instrument records. While data inter-calibration techniques often yield continuous and reliable data for trend analysis, less attention is generally paid to maintaining higher-order statistics such as variance and autocorrelation. A growing body of work uses these metrics to quantify the stability or resilience of a system under study and potentially to anticipate an approaching critical transition in the system. Exploring the degree to which changes in resilience indicators such as the variance or autocorrelation can be attributed to non-stationary characteristics of the measurement process – rather than actual changes in the dynamical properties of the system – is important in this context. In this work we use both synthetic and empirical data to explore how changes in the noise structure of a data set are propagated into the commonly used resilience metrics lag-one autocorrelation and variance. We focus on examples from remotely sensed vegetation indicators such as vegetation optical depth and the normalized difference vegetation index from different satellite sources. We find that time series resulting from mixing signals from sensors with varied uncertainties and covering overlapping time spans can lead to biases in inferred resilience changes. These biases are typically more pronounced when resilience metrics are aggregated (for example, by land-cover type or region), whereas estimates for individual time series remain reliable at reasonable sensor signal-to-noise ratios. Our work provides guidelines for the treatment and aggregation of multi-instrument data in studies of critical transitions and resilience. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1322 Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-589120 SN - 1866-8372 IS - 1322 SP - 173 EP - 183 ER - TY - JOUR A1 - Smith, Taylor A1 - Zotta, Ruxandra-Maria A1 - Boulton, Chris A. A1 - Lenton, Timothy M. A1 - Dorigo, Wouter A1 - Boers, Niklas T1 - Reliability of resilience estimation based on multi-instrument time series JF - Earth System Dynamics N2 - Many widely used observational data sets are comprised of several overlapping instrument records. While data inter-calibration techniques often yield continuous and reliable data for trend analysis, less attention is generally paid to maintaining higher-order statistics such as variance and autocorrelation. A growing body of work uses these metrics to quantify the stability or resilience of a system under study and potentially to anticipate an approaching critical transition in the system. Exploring the degree to which changes in resilience indicators such as the variance or autocorrelation can be attributed to non-stationary characteristics of the measurement process – rather than actual changes in the dynamical properties of the system – is important in this context. In this work we use both synthetic and empirical data to explore how changes in the noise structure of a data set are propagated into the commonly used resilience metrics lag-one autocorrelation and variance. We focus on examples from remotely sensed vegetation indicators such as vegetation optical depth and the normalized difference vegetation index from different satellite sources. We find that time series resulting from mixing signals from sensors with varied uncertainties and covering overlapping time spans can lead to biases in inferred resilience changes. These biases are typically more pronounced when resilience metrics are aggregated (for example, by land-cover type or region), whereas estimates for individual time series remain reliable at reasonable sensor signal-to-noise ratios. Our work provides guidelines for the treatment and aggregation of multi-instrument data in studies of critical transitions and resilience. Y1 - 2023 U6 - https://doi.org/10.5194/esd-14-173-2023 SN - 2190-4987 VL - 14 SP - 173 EP - 183 PB - Copernicus Publications CY - Göttingen ER - TY - JOUR A1 - Steffen, Will A1 - Röckstrom, Johan A1 - Richardson, Katherine A1 - Lenton, Timothy M. A1 - Folke, Carl A1 - Liverman, Diana A1 - Summerhayes, Colin P. A1 - Barnosky, Anthony D. A1 - Cornell, Sarah E. A1 - Crucifix, Michel A1 - Donges, Jonathan Friedemann A1 - Fetzer, Ingo A1 - Lade, Steven J. A1 - Scheffer, Marten A1 - Winkelmann, Ricarda A1 - Schellnhuber, Hans Joachim T1 - Trajectories of the Earth System in the Anthropocene JF - Proceedings of the National Academy of Sciences of the United States of America N2 - We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a "Hothouse Earth" pathway even as human emissions are reduced. Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene. We examine the evidence that such a threshold might exist and where it might be. If the threshold is crossed, the resulting trajectory would likely cause serious disruptions to ecosystems, society, and economies. Collective human action is required to steer the Earth System away from a potential threshold and stabilize it in a habitable interglacial-like state. Such action entails stewardship of the entire Earth System-biosphere, climate, and societies-and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values. KW - Earth System trajectories KW - climate change KW - Anthropocene KW - biosphere feedbacks KW - tipping elements Y1 - 2018 U6 - https://doi.org/10.1073/pnas.1810141115 SN - 0027-8424 VL - 115 IS - 33 SP - 8252 EP - 8259 PB - National Acad. of Sciences CY - Washington ER -