@article{WarszawskiKrieglerLentonetal.2021, author = {Warszawski, Lila and Kriegler, Elmar and Lenton, Timothy M. and Gaffney, Owen and Jacob, Daniela and Klingenfeld, Daniel and Koide, Ryu and Costa, Mar{\´i}a M{\´a}{\~n}ez and Messner, Dirk and Nakicenovic, Nebojsa and Schellnhuber, Hans Joachim and Schlosser, Peter and Takeuchi, Kazuhiko and van der Leeuw, Sander and Whiteman, Gail and Rockstr{\"o}m, Johan}, title = {All options, not silver bullets, needed to limit global warming to 1.5 °C}, series = {Environmental research letters}, volume = {16}, journal = {Environmental research letters}, number = {6}, publisher = {IOP Publishing}, address = {Bristol}, issn = {1748-9326}, doi = {10.1088/1748-9326/abfeec}, pages = {15}, year = {2021}, abstract = {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).}, language = {en} } @article{RockstroemKotzeMilutinovićetal.2024, author = {Rockstr{\"o}m, Johan and Kotz{\´e}, Louis and Milutinović, Svetlana and Biermann, Frank and Brovkin, Victor and Donges, Jonathan and Ebbesson, Jonas and French, Duncan and Gupta, Joyeeta and Kim, Rakhyun and Lenton, Timothy and Lenzi, Dominic and Nakicenovic, Nebojsa and Neumann, Barbara and Schuppert, Fabian and Winkelmann, Ricarda and Bosselmann, Klaus and Folke, Carl and Lucht, Wolfgang and Schlosberg, David and Richardson, Katherine and Steffen, Will}, title = {The planetary commons}, series = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {121}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {5}, publisher = {National Academy of Sciences}, address = {Washington, DC}, issn = {1091-6490}, doi = {10.1073/pnas.2301531121}, pages = {10}, year = {2024}, abstract = {The Anthropocene signifies the start of a no- analogue tra­jectory of the Earth system that is fundamentally different from the Holocene. This new trajectory is characterized by rising risks of triggering irreversible and unmanageable shifts in Earth system functioning. We urgently need a new global approach to safeguard critical Earth system regulating functions more effectively and comprehensively. The global commons framework is the closest example of an existing approach with the aim of governing biophysical systems on Earth upon which the world collectively depends. Derived during stable Holocene conditions, the global commons framework must now evolve in the light of new Anthropocene dynamics. This requires a fundamental shift from a focus only on governing shared resources beyond national jurisdiction, to one that secures critical functions of the Earth system irrespective of national boundaries. We propose a new framework—the planetary commons—which differs from the global commons frame­work by including not only globally shared geographic regions but also critical biophysical systems that regulate the resilience and state, and therefore livability, on Earth. The new planetary commons should articulate and create comprehensive stewardship obligations through Earth system governance aimed at restoring and strengthening planetary resilience and justice.}, language = {en} }