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This dataset contains a set of climate scenario that have been developed for the Network for Greening the Financial System (NGFS). The NGFS is a group of 83 central banks and supervisors and 12 observers committed to sharing best practices, contributing to the development of climate– and environment–related risk management in the financial sector and mobilising mainstream finance to support the transition toward a sustainable economy. The scenarios in this dataset were produced by NGFS Workstream 3 in partnership with an academic consortium from the Potsdam Institute for Climate Impact Research (PIK), International Institute for Applied Systems Analysis (IIASA), University of Maryland (UMD), Climate Analytics (CA), the Eidgenössische Technische Hochschule Zürich (ETH) and the National Institute of Economic and Social Research (NIESR). The Phase 3 bespoke scenarios are generated by state-of-the-art well-established integrated assessment models (IAMs), namely GCAM, MESSAGEix-GLOBIOM and REMIND-MAgPIE. These models allow the estimation of global and regional mitigation costs, the analysis of energy system transition characteristics, the quantification of investments required to transform the energy system, and the identification of synergies and trade-off of sustainable development pathways. Technical documentation is available to help users access the datasets. The documentation describes the models and variables, as well as provides detailed guidance for database users. Scenario presentation materials and the user guide are also available at the NGFS portal.

The use of scenarios and modelling methods are pillars in IPCC Working Group III (WGIII) Assessment Reports. Past WGIII assessment report cycles identified knowledge gaps about the integration of modelling across scales and disciplines, mainly between global integrated assessment modelling methods and bottom-up modelling insights of mitigation responses. The need to improve the transparency of model assumptions and enhance the communication of scenario results was also recognised. This annex on Scenarios and Modelling Methods aims to address some of these gaps by detailing the modelling frameworks applied in the WGIII Sixth Assessment Report (AR6) chapters and disclose scenario assumptions and its key parameters. It has been explicitly included in the Scoping Meeting Report of the WGIII contribution to the AR6 and approved by the IPCC Panel at the 46th Session of the Panel.

The use of scenarios and modelling methods are pillars in IPCC Working Group III (WGIII) Assessment Reports. Past WGIII assessment report cycles identified knowledge gaps about the integration of modelling across scales and disciplines, mainly between global integrated assessment modelling methods and bottom-up modelling insights of mitigation responses. The need to improve the transparency of model assumptions and enhance the communication of scenario results was also recognised. This annex on Scenarios and Modelling Methods aims to address some of these gaps by detailing the modelling frameworks applied in the WGIII Sixth Assessment Report (AR6) chapters and disclose scenario assumptions and its key parameters. It has been explicitly included in the Scoping Meeting Report of the WGIII contribution to the AR6 and approved by the IPCC Panel at the 46th Session of the Panel.

The use of scenarios and modelling methods are pillars in IPCC Working Group III (WGIII) Assessment Reports. Past WGIII assessment report cycles identified knowledge gaps about the integration of modelling across scales and disciplines, mainly between global integrated assessment modelling methods and bottom-up modelling insights of mitigation responses. The need to improve the transparency of model assumptions and enhance the communication of scenario results was also recognised. This annex on Scenarios and Modelling Methods aims to address some of these gaps by detailing the modelling frameworks applied in the WGIII Sixth Assessment Report (AR6) chapters and disclose scenario assumptions and its key parameters. It has been explicitly included in the Scoping Meeting Report of the WGIII contribution to the AR6 and approved by the IPCC Panel at the 46th Session of the Panel.

Long-term global emission scenarios enable the analysis of future climate change, impacts, and response strategies by providing insight into possible future developments and linking these different climate research elements. Such scenarios play a crucial role in the climate change literature informing the Intergovernmental Panel on Climate Change’s (IPCC) Assessment Reports (ARs) and support policymakers. This article reviews the evolution of emission scenarios, since 1990, by focusing on scenario critiques and responses as published in the literature. We focus on the issues raised in the critiques and the possible impact on scenario development. The critique (280) focuses on four areas: 1) key scenario assumptions (40%), 2) the emissions range covered by the scenarios and missing scenarios (25%), 3) methodological issues (24%), and 4) the policy relevance and handling of uncertainty (11%). Scenario critiques have become increasingly influential since 2000. Some areas of critique have decreased or become less prominent (probability, development process, convergence assumptions, and economic metrics). Other areas have become more dominant over time (e.g., policy relevance & implications of scenarios, transparency, Negative Emissions Technologies (NETs) assumptions, missing scenarios). Several changes have been made in developing scenarios and their content that respond to the critique.

This dataset contains a set of climate scenario that have been developed for the Network for Greening the Financial System (NGFS). The NGFS is a group of 83 central banks and supervisors and 12 observers committed to sharing best practices, contributing to the development of climate– and environment–related risk management in the financial sector and mobilising mainstream finance to support the transition toward a sustainable economy. The scenarios in this dataset were produced by NGFS Workstream 3 in partnership with an academic consortium from the Potsdam Institute for Climate Impact Research (PIK), International Institute for Applied Systems Analysis (IIASA), University of Maryland (UMD), Climate Analytics (CA), the Eidgenössische Technische Hochschule Zürich (ETH) and the National Institute of Economic and Social Research (NIESR). The Phase 3 bespoke scenarios are generated by state-of-the-art well-established integrated assessment models (IAMs), namely GCAM, MESSAGEix-GLOBIOM and REMIND-MAgPIE. These models allow the estimation of global and regional mitigation costs, the analysis of energy system transition characteristics, the quantification of investments required to transform the energy system, and the identification of synergies and trade-off of sustainable development pathways. Technical documentation is available to help users access the datasets. The documentation describes the models and variables, as well as provides detailed guidance for database users. Scenario presentation materials and the user guide are also available at the NGFS portal.

This dataset contains a set of climate scenario that have been developed for the Network for Greening the Financial System (NGFS). The NGFS is a group of 83 central banks and supervisors and 12 observers committed to sharing best practices, contributing to the development of climate– and environment–related risk management in the financial sector and mobilising mainstream finance to support the transition toward a sustainable economy. The scenarios in this dataset were produced by NGFS Workstream 2 in partnership with an academic consortium from the Potsdam Institute for Climate Impact Research (PIK), International Institute for Applied Systems Analysis (IIASA), University of Maryland (UMD), Climate Analytics (CA), the Eidgenössische Technische Hochschule Zürich (ETH) and the National Institute of Economic and Social Research (NIESR). The Phase 2 bespoke scenarios are generated by state-of-the-art well-established integrated assessment models (IAMs), namely GCAM, MESSAGEix-GLOBIOM and REMIND-MAgPIE. These models allow the estimation of global and regional mitigation costs, the analysis of energy system transition characteristics, the quantification of investments required to transform the energy system, and the identification of synergies and trade-off of sustainable development pathways. Technical documentation is available to help users access the datasets. The documentation describes the models and variables, as well as provides detailed guidance for database users. Scenario presentation materials and the user guide are also available at the NGFS portal.

Download information The data is available for download at the NGFS Scenario Explorer. The license permits use of the scenario ensemble for scientific research and commercial use, but restricts redistribution of substantial parts of the data. Please refer to the FAQ and legal code for more information. Version 2.2 (28 June 2021) Correction of Emission and Carbon Price variables at the native region level for the REMIND-MAgPIE 2.1-4.2 model, Net Zero 2050 scenario (see detailed list at the bottom of this message). Correction of historic (pre-2020) global level carbon prices for the REMIND-MAgPIE 2.1-4.2 model in Divergent Net Zero Scenario In the downloadable file names for Downscaled Data, Climate Damages and NIGEM outputs, space characters have been replaced with underscores. Because the url's for these files refer to the file names, the old links for these files no longer work and unregistered users should request new download link. Solved an issue of incorrect displaying of region names for the "REMIND-MAgPIE 2.1-4.2 IntegratedPhysicalDamages (median/95th)" models in the Scenario Explorer. About the data set This dataset contains a set of climate scenario that have been developed for the Network for Greening the Financial System (NGFS). The NGFS is a group of 83 central banks and supervisors and 12 observers committed to sharing best practices, contributing to the development of climate– and environment–related risk management in the financial sector and mobilising mainstream finance to support the transition toward a sustainable economy. The scenarios in this dataset were produced by NGFS Workstream 2 in partnership with an academic consortium from the Potsdam Institute for Climate Impact Research (PIK), International Institute for Applied Systems Analysis (IIASA), University of Maryland (UMD), Climate Analytics (CA), the Eidgenössische Technische Hochschule Zürich (ETH) and the National Institute of Economic and Social Research (NIESR). The Phase 2 bespoke scen

This document provides technical information on the two datasets behind the NGFS scenarios. It is intended to answer technical questions for those who want to perform analyses on the datasets themselves. It is an update of the Technical Documentation published in June 2020 alongside the first set of NGFS Scenarios. It is therefore aligned with the second set of NGFS Scenarios, released in June 2021.

This document provides technical information on the two datasets behind the NGFS scenarios. It is intended to answer technical questions for those who want to perform analyses on the datasets themselves. It is an update of the Technical Documentation published in June 2020 alongside the first set of NGFS Scenarios. It is therefore aligned with the second set of NGFS Scenarios, released in June 2021.

This document provides technical information on the two datasets behind the NGFS scenarios. It is intended to answer technical questions for those who want to perform analyses on the datasets themselves. It is an update of the Technical Documentation published in June 2020 alongside the first set of NGFS Scenarios. It is therefore aligned with the second set of NGFS Scenarios, released in June 2021.

Given the increasing interest in keeping global warming below 1.5°C, a key question is what this would mean for China's emission pathway, energy restructuring, and decarbonization. By conducting a multimodel study, we find that the 1.5°C-consistent goal would require China to reduce its carbon emissions and energy consumption by more than 90 and 39%, respectively, compared with the "no policy" case. Negative emission technologies play an important role in achieving near-zero emissions, with captured carbon accounting on average for 20% of the total reductions in 2050. Our multimodel comparisons reveal large differences in necessary emission reductions across sectors, whereas what is consistent is that the power sector is required to achieve full decarbonization by 2050. The cross-model averages indicate that China's accumulated policy costs may amount to 2.8 to 5.7% of its gross domestic product by 2050, given the 1.5°C warming limit.

Given the increasing interest in keeping global warming below 1.5°C, a key question is what this would mean for China's emission pathway, energy restructuring, and decarbonization. By conducting a multimodel study, we find that the 1.5°C-consistent goal would require China to reduce its carbon emissions and energy consumption by more than 90 and 39%, respectively, compared with the "no policy" case. Negative emission technologies play an important role in achieving near-zero emissions, with captured carbon accounting on average for 20% of the total reductions in 2050. Our multimodel comparisons reveal large differences in necessary emission reductions across sectors, whereas what is consistent is that the power sector is required to achieve full decarbonization by 2050. The cross-model averages indicate that China's accumulated policy costs may amount to 2.8 to 5.7% of its gross domestic product by 2050, given the 1.5°C warming limit.

Background: Midwifery care is associated with positive birth outcomes, access to community birth options, and judicious use of interventions. The aim of this study was to characterize and compare maternity care preferences of university students across a range of maternity care systems and to explore whether preferences align with evidence- based recommendations and options available. Methods: A cross-sectional, web-based survey was completed in 2014-2015 by a convenience sample of university students in 8 high-income countries across 4 continents (n=4,569). In addition to describing preferences for midwifery care and community birth options across countries, socio-demographic characteristics, psychological factors, knowledge about pregnancy and birth, and sources of information that shaped students’ attitudes towards birth were examined in relation to preferences for midwifery care and community birth options. Results: Approximately half of the student respondents (48. 2%) preferred midwifery-led care for a healthy pregnancy, 9.5% would choose to birth in a birthing center, and 4.5% preferred a home birth. Preference for midwifery care varied from 10.3% among women in the United States to 78.6% among women in England. Preferences for home birth varied from 0.3% among US women to 18.3% among Canadian women. Women, health science students, those with low childbirth fear, who learned about pregnancy and birth from friends (compared to other sources, e.g. the media) and those who responded from Europe were significantly more likely to prefer midwifery care and community birth. High confidence in knowledge of pregnancy and birth was linked to significantly higher odds of community birth preferences and midwifery care preferences Conclusions: It would be beneficial to integrate childbirth education into high school curricula, to promote knowledge of midwifery care, pregnancy and childbirth and reduce fear among prospective parents. Community birth options need to be expa

Background: Midwifery care is associated with positive birth outcomes, access to community birth options, and judicious use of interventions. The aim of this study was to characterize and compare maternity care preferences of university students across a range of maternity care systems and to explore whether preferences align with evidence- based recommendations and options available. Methods: A cross-sectional, web-based survey was completed in 2014-2015 by a convenience sample of university students in 8 high-income countries across 4 continents (n=4,569). In addition to describing preferences for midwifery care and community birth options across countries, socio-demographic characteristics, psychological factors, knowledge about pregnancy and birth, and sources of information that shaped students’ attitudes towards birth were examined in relation to preferences for midwifery care and community birth options. Results: Approximately half of the student respondents (48. 2%) preferred midwifery-led care for a healthy pregnancy, 9.5% would choose to birth in a birthing center, and 4.5% preferred a home birth. Preference for midwifery care varied from 10.3% among women in the United States to 78.6% among women in England. Preferences for home birth varied from 0.3% among US women to 18.3% among Canadian women. Women, health science students, those with low childbirth fear, who learned about pregnancy and birth from friends (compared to other sources, e.g. the media) and those who responded from Europe were significantly more likely to prefer midwifery care and community birth. High confidence in knowledge of pregnancy and birth was linked to significantly higher odds of community birth preferences and midwifery care preferences Conclusions: It would be beneficial to integrate childbirth education into high school curricula, to promote knowledge of midwifery care, pregnancy and childbirth and reduce fear among prospective parents. Community birth options need to be expa

Background: Midwifery care is associated with positive birth outcomes, access to community birth options, and judicious use of interventions. The aim of this study was to characterize and compare maternity care preferences of university students across a range of maternity care systems and to explore whether preferences align with evidence- based recommendations and options available. Methods: A cross-sectional, web-based survey was completed in 2014-2015 by a convenience sample of university students in 8 high-income countries across 4 continents (n=4,569). In addition to describing preferences for midwifery care and community birth options across countries, socio-demographic characteristics, psychological factors, knowledge about pregnancy and birth, and sources of information that shaped students’ attitudes towards birth were examined in relation to preferences for midwifery care and community birth options. Results: Approximately half of the student respondents (48. 2%) preferred midwifery-led care for a healthy pregnancy, 9.5% would choose to birth in a birthing center, and 4.5% preferred a home birth. Preference for midwifery care varied from 10.3% among women in the United States to 78.6% among women in England. Preferences for home birth varied from 0.3% among US women to 18.3% among Canadian women. Women, health science students, those with low childbirth fear, who learned about pregnancy and birth from friends (compared to other sources, e.g. the media) and those who responded from Europe were significantly more likely to prefer midwifery care and community birth. High confidence in knowledge of pregnancy and birth was linked to significantly higher odds of community birth preferences and midwifery care preferences Conclusions: It would be beneficial to integrate childbirth education into high school curricula, to promote knowledge of midwifery care, pregnancy and childbirth and reduce fear among prospective parents. Community birth options need to be expa

Many 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.

Background: Midwifery care is associated with positive birth outcomes, access to community birth options, and judicious use of interventions. The aim of this study was to characterize and compare maternity care preferences of university students across a range of maternity care systems and to explore whether preferences align with evidence- based recommendations and options available. Methods: A cross-sectional, web-based survey was completed in 2014-2015 by a convenience sample of university students in 8 high-income countries across 4 continents (n=4,569). In addition to describing preferences for midwifery care and community birth options across countries, socio-demographic characteristics, psychological factors, knowledge about pregnancy and birth, and sources of information that shaped students’ attitudes towards birth were examined in relation to preferences for midwifery care and community birth options. Results: Approximately half of the student respondents (48. 2%) preferred midwifery-led care for a healthy pregnancy, 9.5% would choose to birth in a birthing center, and 4.5% preferred a home birth. Preference for midwifery care varied from 10.3% among women in the United States to 78.6% among women in England. Preferences for home birth varied from 0.3% among US women to 18.3% among Canadian women. Women, health science students, those with low childbirth fear, who learned about pregnancy and birth from friends (compared to other sources, e.g. the media) and those who responded from Europe were significantly more likely to prefer midwifery care and community birth. High confidence in knowledge of pregnancy and birth was linked to significantly higher odds of community birth preferences and midwifery care preferences Conclusions: It would be beneficial to integrate childbirth education into high school curricula, to promote knowledge of midwifery care, pregnancy and childbirth and reduce fear among prospective parents. Community birth options need to be expa

Background: Midwifery care is associated with positive birth outcomes, access to community birth options, and judicious use of interventions. The aim of this study was to characterize and compare maternity care preferences of university students across a range of maternity care systems and to explore whether preferences align with evidence- based recommendations and options available. Methods: A cross-sectional, web-based survey was completed in 2014-2015 by a convenience sample of university students in 8 high-income countries across 4 continents (n=4,569). In addition to describing preferences for midwifery care and community birth options across countries, socio-demographic characteristics, psychological factors, knowledge about pregnancy and birth, and sources of information that shaped students’ attitudes towards birth were examined in relation to preferences for midwifery care and community birth options. Results: Approximately half of the student respondents (48. 2%) preferred midwifery-led care for a healthy pregnancy, 9.5% would choose to birth in a birthing center, and 4.5% preferred a home birth. Preference for midwifery care varied from 10.3% among women in the United States to 78.6% among women in England. Preferences for home birth varied from 0.3% among US women to 18.3% among Canadian women. Women, health science students, those with low childbirth fear, who learned about pregnancy and birth from friends (compared to other sources, e.g. the media) and those who responded from Europe were significantly more likely to prefer midwifery care and community birth. High confidence in knowledge of pregnancy and birth was linked to significantly higher odds of community birth preferences and midwifery care preferences Conclusions: It would be beneficial to integrate childbirth education into high school curricula, to promote knowledge of midwifery care, pregnancy and childbirth and reduce fear among prospective parents. Community birth options need to be expa

Many 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.

Background: Midwifery care is associated with positive birth outcomes, access to community birth options, and judicious use of interventions. The aim of this study was to characterize and compare maternity care preferences of university students across a range of maternity care systems and to explore whether preferences align with evidence- based recommendations and options available. Methods: A cross-sectional, web-based survey was completed in 2014-2015 by a convenience sample of university students in 8 high-income countries across 4 continents (n=4,569). In addition to describing preferences for midwifery care and community birth options across countries, socio-demographic characteristics, psychological factors, knowledge about pregnancy and birth, and sources of information that shaped students’ attitudes towards birth were examined in relation to preferences for midwifery care and community birth options. Results: Approximately half of the student respondents (48. 2%) preferred midwifery-led care for a healthy pregnancy, 9.5% would choose to birth in a birthing center, and 4.5% preferred a home birth. Preference for midwifery care varied from 10.3% among women in the United States to 78.6% among women in England. Preferences for home birth varied from 0.3% among US women to 18.3% among Canadian women. Women, health science students, those with low childbirth fear, who learned about pregnancy and birth from friends (compared to other sources, e.g. the media) and those who responded from Europe were significantly more likely to prefer midwifery care and community birth. High confidence in knowledge of pregnancy and birth was linked to significantly higher odds of community birth preferences and midwifery care preferences Conclusions: It would be beneficial to integrate childbirth education into high school curricula, to promote knowledge of midwifery care, pregnancy and childbirth and reduce fear among prospective parents. Community birth options need to be expa

This dataset contains a set of climate scenario that have been developed for the Network for Greening the Financial System (NGFS). The NGFS is a group of 83 central banks and supervisors and 12 observers committed to sharing best practices, contributing to the development of climate– and environment–related risk management in the financial sector and mobilising mainstream finance to support the transition toward a sustainable economy. The scenarios in this dataset were produced by NGFS Workstream 2 in partnership with an academic consortium from the Potsdam Institute for Climate Impact Research (PIK), International Institute for Applied Systems Analysis (IIASA), University of Maryland (UMD), Climate Analytics (CA), the Eidgenössische Technische Hochschule Zürich (ETH) and the National Institute of Economic and Social Research (NIESR). The Phase 2 bespoke scenarios are generated by state-of-the-art well-established integrated assessment models (IAMs), namely GCAM, MESSAGEix-GLOBIOM and REMIND-MAgPIE. These models allow the estimation of global and regional mitigation costs, the analysis of energy system transition characteristics, the quantification of investments required to transform the energy system, and the identification of synergies and trade-off of sustainable development pathways. Technical documentation is available to help users access the datasets. The documentation describes the models and variables, as well as provides detailed guidance for database users. Scenario presentation materials and the user guide are also available at the NGFS portal.

This document provides technical information on the two datasets constituting the NGFS reference scenarios (see NGFS Climate Scenarios for central banks and supervisors). One dataset includes transition pathways and data on macro-economic impacts from physical risks, both of which available in the NGFS Scenario Explorer provided by IIASA. The other dataset covers the physical impact data collected by the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP). These datasets are generated with a suite of models including integrated assessment models, general circulation models, sectoral impact models and global macroeconomic damage functions. They are linked together in a coherent way by aligning global warming levels. For each dataset, the most important technical details of the underlying academic work and a short user guide are provided. These are complemented by links to other resources with more detailed information.

This document provides technical information on the two datasets constituting the NGFS reference scenarios (see NGFS Climate Scenarios for central banks and supervisors). One dataset includes transition pathways and data on macro-economic impacts from physical risks, both of which available in the NGFS Scenario Explorer provided by IIASA. The other dataset covers the physical impact data collected by the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP). These datasets are generated with a suite of models including integrated assessment models, general circulation models, sectoral impact models and global macroeconomic damage functions. They are linked together in a coherent way by aligning global warming levels. For each dataset, the most important technical details of the underlying academic work and a short user guide are provided. These are complemented by links to other resources with more detailed information.

This document provides technical information on the two datasets constituting the NGFS reference scenarios (see NGFS Climate Scenarios for central banks and supervisors). One dataset includes transition pathways and data on macro-economic impacts from physical risks, both of which available in the NGFS Scenario Explorer provided by IIASA. The other dataset covers the physical impact data collected by the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP). These datasets are generated with a suite of models including integrated assessment models, general circulation models, sectoral impact models and global macroeconomic damage functions. They are linked together in a coherent way by aligning global warming levels. For each dataset, the most important technical details of the underlying academic work and a short user guide are provided. These are complemented by links to other resources with more detailed information.

Many 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.

Many 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.

Many 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.

This paper describes GCAM v5.1, an open source model that represents the linkages between energy, water, land, climate, and economic systems. GCAM is a market equilibrium model, is global in scope, and operates from 1990 to 2100 in 5-year time steps. It can be used to examine, for example, how changes in population, income, or technology cost might alter crop production, energy demand, or water withdrawals, or how changes in one region's demand for energy affect energy, water, and land in other regions. This paper describes the model, including its assumptions, inputs, and outputs. We then use 11 scenarios, varying the socioeconomic and climate policy assumptions, to illustrate the results from the model. The resulting scenarios demonstrate a wide range of potential future energy, water, and land uses. We compare the results from GCAM v5.1 to historical data and to future scenario simulations from earlier versions of GCAM and from other models. Finally, we provide information on how to obtain the model.

This paper describes GCAM v5.1, an open source model that represents the linkages between energy, water, land, climate, and economic systems. GCAM is a market equilibrium model, is global in scope, and operates from 1990 to 2100 in 5-year time steps. It can be used to examine, for example, how changes in population, income, or technology cost might alter crop production, energy demand, or water withdrawals, or how changes in one region's demand for energy affect energy, water, and land in other regions. This paper describes the model, including its assumptions, inputs, and outputs. We then use 11 scenarios, varying the socioeconomic and climate policy assumptions, to illustrate the results from the model. The resulting scenarios demonstrate a wide range of potential future energy, water, and land uses. We compare the results from GCAM v5.1 to historical data and to future scenario simulations from earlier versions of GCAM and from other models. Finally, we provide information on how to obtain the model.

For aiming to keep global warming well-below 2 °C and pursue efforts to limit it to 1.5 °C, as set out in the Paris Agreement, a full-fledged assessment of negative emission technologies (NETs) that remove carbon dioxide from the atmosphere is crucial to inform science-based policy making. With the Paris Agreement in mind, we re-analyse available scenario evidence to understand the roles of NETs in 1.5 °C and 2 °C scenarios and, for the first time, link this to a systematic review of findings in the underlying literature. In line with previous research, we find that keeping warming below 1.5 °C requires a rapid large-scale deployment of NETs, while for 2 °C, we can still limit NET deployment substantially by ratcheting up near-term mitigation ambition. Most recent evidence stresses the importance of future socio-economic conditions in determining the flexibility of NET deployment and suggests opportunities for hedging technology risks by adopting portfolios of NETs. Importantly, our thematic review highlights that there is a much richer set of findings on NETs than commonly reflected upon both in scientific assessments and available reviews. In particular, beyond the common findings on NETs underpinned by dozens of studies around early scale-up, the changing shape of net emission pathways or greater flexibility in the timing of climate policies, there is a suite of “niche and emerging findings”, e.g. around innovation needs and rapid technological change, termination of NETs at the end of the twenty-first century or the impacts of climate change on the effectiveness of NETs that have not been widely appreciated. Future research needs to explore the role of climate damages on NET uptake, better understand the geophysical constraints of NET deployment (e.g. water, geological storage, climate feedbacks), and provide a more systematic assessment of NET portfolios in the context of sustainable development goals.

For aiming to keep global warming well-below 2 °C and pursue efforts to limit it to 1.5 °C, as set out in the Paris Agreement, a full-fledged assessment of negative emission technologies (NETs) that remove carbon dioxide from the atmosphere is crucial to inform science-based policy making. With the Paris Agreement in mind, we re-analyse available scenario evidence to understand the roles of NETs in 1.5 °C and 2 °C scenarios and, for the first time, link this to a systematic review of findings in the underlying literature. In line with previous research, we find that keeping warming below 1.5 °C requires a rapid large-scale deployment of NETs, while for 2 °C, we can still limit NET deployment substantially by ratcheting up near-term mitigation ambition. Most recent evidence stresses the importance of future socio-economic conditions in determining the flexibility of NET deployment and suggests opportunities for hedging technology risks by adopting portfolios of NETs. Importantly, our thematic review highlights that there is a much richer set of findings on NETs than commonly reflected upon both in scientific assessments and available reviews. In particular, beyond the common findings on NETs underpinned by dozens of studies around early scale-up, the changing shape of net emission pathways or greater flexibility in the timing of climate policies, there is a suite of “niche and emerging findings”, e.g. around innovation needs and rapid technological change, termination of NETs at the end of the twenty-first century or the impacts of climate change on the effectiveness of NETs that have not been widely appreciated. Future research needs to explore the role of climate damages on NET uptake, better understand the geophysical constraints of NET deployment (e.g. water, geological storage, climate feedbacks), and provide a more systematic assessment of NET portfolios in the context of sustainable development goals.

For aiming to keep global warming well-below 2 °C and pursue efforts to limit it to 1.5 °C, as set out in the Paris Agreement, a full-fledged assessment of negative emission technologies (NETs) that remove carbon dioxide from the atmosphere is crucial to inform science-based policy making. With the Paris Agreement in mind, we re-analyse available scenario evidence to understand the roles of NETs in 1.5 °C and 2 °C scenarios and, for the first time, link this to a systematic review of findings in the underlying literature. In line with previous research, we find that keeping warming below 1.5 °C requires a rapid large-scale deployment of NETs, while for 2 °C, we can still limit NET deployment substantially by ratcheting up near-term mitigation ambition. Most recent evidence stresses the importance of future socio-economic conditions in determining the flexibility of NET deployment and suggests opportunities for hedging technology risks by adopting portfolios of NETs. Importantly, our thematic review highlights that there is a much richer set of findings on NETs than commonly reflected upon both in scientific assessments and available reviews. In particular, beyond the common findings on NETs underpinned by dozens of studies around early scale-up, the changing shape of net emission pathways or greater flexibility in the timing of climate policies, there is a suite of “niche and emerging findings”, e.g. around innovation needs and rapid technological change, termination of NETs at the end of the twenty-first century or the impacts of climate change on the effectiveness of NETs that have not been widely appreciated. Future research needs to explore the role of climate damages on NET uptake, better understand the geophysical constraints of NET deployment (e.g. water, geological storage, climate feedbacks), and provide a more systematic assessment of NET portfolios in the context of sustainable development goals.

Climate change mitigation scenarios are finding a wider set of users, including companies and financial institutions. Increased collaboration between scenario producers and these new communities will be mutually beneficial, educating companies and investors on climate risks while grounding climate science in real-world needs.

Climate change mitigation scenarios are finding a wider set of users, including companies and financial institutions. Increased collaboration between scenario producers and these new communities will be mutually beneficial, educating companies and investors on climate risks while grounding climate science in real-world needs.

The 2015 Paris Agreement calls for countries to pursue efforts to limit global-mean temperature rise to 1.5 °C. The transition pathways that can meet such a target have not, however, been extensively explored. Here we describe scenarios that limit end-of-century radiative forcing to 1.9 W m−2, and consequently restrict median warming in the year 2100 to below 1.5 °C. We use six integrated assessment models and a simple climate model, under different socio-economic, technological and resource assumptions from five Shared Socio-economic Pathways (SSPs). Some, but not all, SSPs are amenable to pathways to 1.5 °C. Successful 1.9 W m−2 scenarios are characterized by a rapid shift away from traditional fossil-fuel use towards large-scale lowcarbon energy supplies, reduced energy use, and carbon-dioxide removal. However, 1.9 W m−2 scenarios could not be achieved in several models under SSPs with strong inequalities, high baseline fossil-fuel use, or scattered short-term climate policy. Further research can help policy-makers to understand the real-world implications of these scenarios.

The 2015 Paris Agreement calls for countries to pursue efforts to limit global-mean temperature rise to 1.5 °C. The transition pathways that can meet such a target have not, however, been extensively explored. Here we describe scenarios that limit end-of-century radiative forcing to 1.9 W m−2, and consequently restrict median warming in the year 2100 to below 1.5 °C. We use six integrated assessment models and a simple climate model, under different socio-economic, technological and resource assumptions from five Shared Socio-economic Pathways (SSPs). Some, but not all, SSPs are amenable to pathways to 1.5 °C. Successful 1.9 W m−2 scenarios are characterized by a rapid shift away from traditional fossil-fuel use towards large-scale lowcarbon energy supplies, reduced energy use, and carbon-dioxide removal. However, 1.9 W m−2 scenarios could not be achieved in several models under SSPs with strong inequalities, high baseline fossil-fuel use, or scattered short-term climate policy. Further research can help policy-makers to understand the real-world implications of these scenarios.

The 2015 Paris Agreement calls for countries to pursue efforts to limit global-mean temperature rise to 1.5 °C. The transition pathways that can meet such a target have not, however, been extensively explored. Here we describe scenarios that limit end-of-century radiative forcing to 1.9 W m−2, and consequently restrict median warming in the year 2100 to below 1.5 °C. We use six integrated assessment models and a simple climate model, under different socio-economic, technological and resource assumptions from five Shared Socio-economic Pathways (SSPs). Some, but not all, SSPs are amenable to pathways to 1.5 °C. Successful 1.9 W m−2 scenarios are characterized by a rapid shift away from traditional fossil-fuel use towards large-scale lowcarbon energy supplies, reduced energy use, and carbon-dioxide removal. However, 1.9 W m−2 scenarios could not be achieved in several models under SSPs with strong inequalities, high baseline fossil-fuel use, or scattered short-term climate policy. Further research can help policy-makers to understand the real-world implications of these scenarios.

The 2015 Paris Agreement calls for countries to pursue efforts to limit global-mean temperature rise to 1.5 °C. The transition pathways that can meet such a target have not, however, been extensively explored. Here we describe scenarios that limit end-of-century radiative forcing to 1.9 W m−2, and consequently restrict median warming in the year 2100 to below 1.5 °C. We use six integrated assessment models and a simple climate model, under different socio-economic, technological and resource assumptions from five Shared Socio-economic Pathways (SSPs). Some, but not all, SSPs are amenable to pathways to 1.5 °C. Successful 1.9 W m−2 scenarios are characterized by a rapid shift away from traditional fossil-fuel use towards large-scale lowcarbon energy supplies, reduced energy use, and carbon-dioxide removal. However, 1.9 W m−2 scenarios could not be achieved in several models under SSPs with strong inequalities, high baseline fossil-fuel use, or scattered short-term climate policy. Further research can help policy-makers to understand the real-world implications of these scenarios.

The 2015 Paris Agreement calls for countries to pursue efforts to limit global-mean temperature rise to 1.5 °C. The transition pathways that can meet such a target have not, however, been extensively explored. Here we describe scenarios that limit end-of-century radiative forcing to 1.9 W m−2, and consequently restrict median warming in the year 2100 to below 1.5 °C. We use six integrated assessment models and a simple climate model, under different socio-economic, technological and resource assumptions from five Shared Socio-economic Pathways (SSPs). Some, but not all, SSPs are amenable to pathways to 1.5 °C. Successful 1.9 W m−2 scenarios are characterized by a rapid shift away from traditional fossil-fuel use towards large-scale lowcarbon energy supplies, reduced energy use, and carbon-dioxide removal. However, 1.9 W m−2 scenarios could not be achieved in several models under SSPs with strong inequalities, high baseline fossil-fuel use, or scattered short-term climate policy. Further research can help policy-makers to understand the real-world implications of these scenarios.

Fossil fuel combustion and land-use change are the two largest contributors to industrial-era increases in atmospheric CO2 concentration. Projections of these are thus fundamental inputs for coupled Earth system models (ESMs) used to estimate the physical and biological consequences of future climate system forcing. While historical data sets are available to inform past and current climate analyses, assessments of future climate change have relied on projections of energy and land use from energy-economic models, constrained by assumptions about future policy, land-use patterns and socio-economic development trajectories. Here we show that the climatic impacts on land ecosystems drive significant feedbacks in energy, agriculture, land use and carbon cycle projections for the twenty-first century. We find that exposure of human-appropriated land ecosystem productivity to biospheric change results in reductions of land area used for crops; increases in managed forest area and carbon stocks; decreases in global crop prices; and reduction in fossil fuel emissions for a low-mid-range forcing scenario. The feedbacks between climate-induced biospheric change and human system forcings to the climate system - demonstrated here - are handled inconsistently, or excluded altogether, in the one-way asynchronous coupling of energy-economic models to ESMs used to date.

Fossil fuel combustion and land-use change are the two largest contributors to industrial-era increases in atmospheric CO2 concentration. Projections of these are thus fundamental inputs for coupled Earth system models (ESMs) used to estimate the physical and biological consequences of future climate system forcing. While historical data sets are available to inform past and current climate analyses, assessments of future climate change have relied on projections of energy and land use from energy-economic models, constrained by assumptions about future policy, land-use patterns and socio-economic development trajectories. Here we show that the climatic impacts on land ecosystems drive significant feedbacks in energy, agriculture, land use and carbon cycle projections for the twenty-first century. We find that exposure of human-appropriated land ecosystem productivity to biospheric change results in reductions of land area used for crops; increases in managed forest area and carbon stocks; decreases in global crop prices; and reduction in fossil fuel emissions for a low-mid-range forcing scenario. The feedbacks between climate-induced biospheric change and human system forcings to the climate system - demonstrated here - are handled inconsistently, or excluded altogether, in the one-way asynchronous coupling of energy-economic models to ESMs used to date.

This paper presents the overview of the Shared Socioeconomic Pathways (SSPs) and their energy, land use, and emissions implications. The SSPs are part of a new scenario framework, established by the climate change research community in order to facilitate the integrated analysis of future climate impacts, vulnerabilities, adaptation, and mitigation. The pathways were developed over the last years as a joint community effort and describe plausible major global developments that together would lead in the future to different challenges for mitigation and adaptation to climate change. The SSPs are based on five narratives describing alternative socio-economic developments, including sustainable development, regional rivalry, inequality, fossil-fueled development, and a middle-of-the-road development. The long-term demographic and economic projections of the SSPs depict a wide uncertainty range consistent with the scenario literature. A multi-model approach was used for the elaboration of the energy, land-use and the emissions trajectories of SSP-based scenarios. The baseline scenarios lead to global energy consumption of 500-1100 EJ in 2100, and feature vastly different land-use dynamics, ranging from a possible reduction in cropland area up to a massive expansion by more than 700 million hectares by 2100. The associated annual CO2 emissions of the baseline scenarios range from about 25 GtCO2 to more than 120 GtCO2 per year by 2100. With respect to mitigation, we find that associated costs strongly depend on three factors: 1) the policy assumptions, 2) the socio-economic narrative, and 3) the stringency of the target. The carbon price for reaching the target of 2.6 W/m2 differs in our analysis thus by about a factor of three across the SSP scenarios. Moreover, many models could not reach this target from the SSPs with high mitigation challenges. While the SSPs were designed to represent different mitigation and adaptation challenges, the resulting narratives and quanti

This paper presents the overview of the Shared Socioeconomic Pathways (SSPs) and their energy, land use, and emissions implications. The SSPs are part of a new scenario framework, established by the climate change research community in order to facilitate the integrated analysis of future climate impacts, vulnerabilities, adaptation, and mitigation. The pathways were developed over the last years as a joint community effort and describe plausible major global developments that together would lead in the future to different challenges for mitigation and adaptation to climate change. The SSPs are based on five narratives describing alternative socio-economic developments, including sustainable development, regional rivalry, inequality, fossil-fueled development, and a middle-of-the-road development. The long-term demographic and economic projections of the SSPs depict a wide uncertainty range consistent with the scenario literature. A multi-model approach was used for the elaboration of the energy, land-use and the emissions trajectories of SSP-based scenarios. The baseline scenarios lead to global energy consumption of 500-1100 EJ in 2100, and feature vastly different land-use dynamics, ranging from a possible reduction in cropland area up to a massive expansion by more than 700 million hectares by 2100. The associated annual CO2 emissions of the baseline scenarios range from about 25 GtCO2 to more than 120 GtCO2 per year by 2100. With respect to mitigation, we find that associated costs strongly depend on three factors: 1) the policy assumptions, 2) the socio-economic narrative, and 3) the stringency of the target. The carbon price for reaching the target of 2.6 W/m2 differs in our analysis thus by about a factor of three across the SSP scenarios. Moreover, many models could not reach this target from the SSPs with high mitigation challenges. While the SSPs were designed to represent different mitigation and adaptation challenges, the resulting narratives and quanti

This paper presents the overview of the Shared Socioeconomic Pathways (SSPs) and their energy, land use, and emissions implications. The SSPs are part of a new scenario framework, established by the climate change research community in order to facilitate the integrated analysis of future climate impacts, vulnerabilities, adaptation, and mitigation. The pathways were developed over the last years as a joint community effort and describe plausible major global developments that together would lead in the future to different challenges for mitigation and adaptation to climate change. The SSPs are based on five narratives describing alternative socio-economic developments, including sustainable development, regional rivalry, inequality, fossil-fueled development, and a middle-of-the-road development. The long-term demographic and economic projections of the SSPs depict a wide uncertainty range consistent with the scenario literature. A multi-model approach was used for the elaboration of the energy, land-use and the emissions trajectories of SSP-based scenarios. The baseline scenarios lead to global energy consumption of 500-1100 EJ in 2100, and feature vastly different land-use dynamics, ranging from a possible reduction in cropland area up to a massive expansion by more than 700 million hectares by 2100. The associated annual CO2 emissions of the baseline scenarios range from about 25 GtCO2 to more than 120 GtCO2 per year by 2100. With respect to mitigation, we find that associated costs strongly depend on three factors: 1) the policy assumptions, 2) the socio-economic narrative, and 3) the stringency of the target. The carbon price for reaching the target of 2.6 W/m2 differs in our analysis thus by about a factor of three across the SSP scenarios. Moreover, many models could not reach this target from the SSPs with high mitigation challenges. While the SSPs were designed to represent different mitigation and adaptation challenges, the resulting narratives and quanti

This paper presents the overview of the Shared Socioeconomic Pathways (SSPs) and their energy, land use, and emissions implications. The SSPs are part of a new scenario framework, established by the climate change research community in order to facilitate the integrated analysis of future climate impacts, vulnerabilities, adaptation, and mitigation. The pathways were developed over the last years as a joint community effort and describe plausible major global developments that together would lead in the future to different challenges for mitigation and adaptation to climate change. The SSPs are based on five narratives describing alternative socio-economic developments, including sustainable development, regional rivalry, inequality, fossil-fueled development, and a middle-of-the-road development. The long-term demographic and economic projections of the SSPs depict a wide uncertainty range consistent with the scenario literature. A multi-model approach was used for the elaboration of the energy, land-use and the emissions trajectories of SSP-based scenarios. The baseline scenarios lead to global energy consumption of 500-1100 EJ in 2100, and feature vastly different land-use dynamics, ranging from a possible reduction in cropland area up to a massive expansion by more than 700 million hectares by 2100. The associated annual CO2 emissions of the baseline scenarios range from about 25 GtCO2 to more than 120 GtCO2 per year by 2100. With respect to mitigation, we find that associated costs strongly depend on three factors: 1) the policy assumptions, 2) the socio-economic narrative, and 3) the stringency of the target. The carbon price for reaching the target of 2.6 W/m2 differs in our analysis thus by about a factor of three across the SSP scenarios. Moreover, many models could not reach this target from the SSPs with high mitigation challenges. While the SSPs were designed to represent different mitigation and adaptation challenges, the resulting narratives and quanti