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Steep emissions reductions are needed in the coming decades to limit warming to 2°C or lower, followed by multiple gigatons of annual carbon dioxide removal (CDR) in the second half of the 21st century. In this presentation we make a first assessment of the “CDR gap” and ask whether countries are preparing for the CDR scale-up challenge. We find that most countries pledge only a small expansion of CDR by 2030 in their nationally determined contributions (NDCs), while only a subset have proposed CDR in their long-term mitigation strategies. There is a significant gap between these proposed CDR levels and levels in scenarios that limit warming to 2°C or lower. While some scenarios have low CDR requirements, these require even steeper emissions reductions that we are not on track to achieve. Most countries prioritize conventional CDR on land (i.e. the management of forest sinks) which has low permanence and may raise land use conflicts. Conventional CDR on land will be extremely difficult just to maintain, let alone expand to meet net zero emissions targets. By contrast, countries focus far less in their NDCs and long-term strategies on novel CDR methods such as bioenergy with carbon capture and storage, direct air capture, or blue carbon. For these technologies to make a meaningful contribution to long-term climate mitigation, urgent support is required in the formative phases of their development. Above all, rapid emissions reductions are needed to reduce our dependence on CDR and prevent a widening CDR gap by 2050.

Intergovernmental Panel on Climate Change (IPCC) assessments are the trusted source of scientific evidence for climate negotiations taking place under the United Nations Framework Convention on Climate Change (UNFCCC), including the first global stocktake under the Paris Agreement that will conclude at COP28 in December 2023. Evidence-based decision making needs to be informed by up-to-date and timely information on key indicators of the state of the climate system and of the human influence on the global climate system. However, successive IPCC reports are published at intervals of 5–10 years, creating potential for an information gap between report cycles. We base this update on the assessment methods used in the IPCC Sixth Assessment Report (AR6) Working Group One (WGI) report, updating the monitoring datasets and to produce updated estimates for key climate indicators including emissions, greenhouse gas concentrations, radiative forcing, surface temperature changes, the Earth’s energy imbalance, warming attributed to human activities, the remaining carbon budget and estimates of global temperature extremes. The purpose of this effort, grounded in an open data, open science approach, is to make annually updated reliable global climate indicators available in the public domain (https://doi.org/10.5281/zenodo.7883758, Smith et al., 2023). As they are traceable and consistent with IPCC report methods, they can be trusted by all parties involved in UNFCCC negotiations and help convey wider understanding of the latest knowledge of the climate system and its direction of travel. The indicators show that human induced warming reached 1.14 [0.9 to 1.4] °C over the 2013–2022 period and 1.26 [1.0 to 1.6] °C in 2022. Human induced warming is increasing at an unprecedented rate of over 0.2 °C per decade. This high rate of warming is caused by a combination of greenhouse gas emissions being at an all-time high of 57 ± 5.6 GtCO2e over the last decade, as well as reductions in the strength of aerosol cooling. Despite this, there are signs that emission levels are starting to stabilise, and we can hope that a continued series of these annual updates might track a real-world change of direction for the climate over this critical decade.

Taking stock of global progress towards achieving the Paris Agreement requires measuring aggregate national action against modelled mitigation pathways. Because of differences in how land-based carbon removals are defined, scientific sources report higher global carbon emissions than national emissions inventories, a gap which will evolve in the future. We establish a first estimate aligning IPCC-assessed pathways with inventories using a climate model to explicitly include indirect carbon removal dynamics on land area reported as managed for by countries. After alignment, we find that key global mitigation benchmarks can appear more ambitious when considering this extra land sink, though changes vary amongst world regions and temperature outcomes. Our results highlight the need to enhance communication between scientific and policy communities to enable more robust alignment in the future.

BackgroundWith the Paris agreement in 2015, the international community set ambitious goals for limiting climate warming and adapting to the impacts of climate change. However, despite the increasing ambition of long-term targets, and progress on adaptation planning, current policies are insufficient to limit warming to safe levels or to adapt to climate impacts on the required scale. Climate policy is multifaceted, multisectoral and will require many different types of policy instruments. The scientific literature on climate change is rapidly expanding and contains a wealth of research on climate policies. Gaining an overview of climate policy research is therefore vital, but beyond the scope of traditional, hand-coded systematic maps.MethodsThis study aims to identify the literature on climate policies from a set of hundreds of thousands of studies on climate change. The studies will be classified according to the type of policy instrument discussed. Due to the scale of literature, only a sample of studies will be screened manually. Inclusion/exclusion, as well as policy and other labels, will be estimated using machine learning for the remaining studies. The map will report the numbers of papers on each policy type from each region and each sector, as well as the extent to which machine-learning is able to classify policy instruments correctly.

Mitigation solutions are often evaluated in terms of costs and greenhouse gas reduction potentials, missing out on the consideration of direct effects on human well-being. Here, we systematically assess the mitigation potential of demand-side options categorized into avoid, shift and improve, and their human well-being links. We show that these options, bridging socio-behavioural, infrastructural and technological domains, can reduce counterfactual sectoral emissions by 40–80% in end-use sectors. Based on expert judgement and an extensive literature database, we evaluate 306 combinations of well-being outcomes and demand-side options, finding largely beneficial effects in improvement in well-being (79% positive, 18% neutral and 3% negative), even though we find low confidence on the social dimensions of well-being. Implementing such nuanced solutions is based axiomatically on an understanding of malleable rather than fixed preferences, and procedurally on changing infrastructures and choice architectures. Results demonstrate the high mitigation potential of demand-side mitigation options that are synergistic with well-being. Evaluation of mitigation actions often focuses on cost and overlooks the direct effects on well-being. This work shows demand-side measures have large mitigation potential and beneficial effects on well-being outcomes.

Climate mitigation research puts increasing emphasis on cities, but much more could be learned from urban case studies. The overall size, geographic scope and topic content of cases remains unknown, resulting in few attempts to synthesise the bottom-up evidence. Here, we use scientometric and machine-learning methods to produce a comprehensive map of the literature. Our database of approximately 4,000 case studies provides a wealth of evidence to search, compare and review. We find that cities in world regions with the highest future mitigation relevance are systematically underrepresented. A map of the evidence allows case studies to be matched with urban typologies in new and more ambitious forms of synthesis, bringing together traditionally separate strands of qualitative and quantitative urban research. Cities around the world are at the forefront of enacting climate mitigation policies, but effective action requires a better understanding of potential solutions. This Review offers a systematic exploration of the urban case study literature and discusses ways to best make use of the growing body of cases.

To track progress towards keeping warming well below 2 °C, as agreed upon in the Paris Agreement, comprehensive and reliable information on anthropogenic sources of greenhouse gas emissions (GHG) is required. Here we provide a dataset on anthropogenic GHG emissions 1970–2019 with a broad country and sector coverage. We build the dataset from recent releases of the “Emissions Database for Global Atmospheric Research” (EDGAR) for CO2 emissions from fossil fuel combustion and industry (FFI), CH4 emissions, N2O emissions, and fluorinated gases, and use a well-established fast-track method to extend this dataset from 2018 to 2019. We complement this with data on net CO2 emissions from land use, land-use change and forestry (LULUCF) from three bookkeeping models. We provide an assessment of the uncertainties in each greenhouse gas at the 90 % confidence interval (5th–95th percentile) by combining statistical analysis and comparisons of global emissions inventories with an expert judgement informed by the relevant scientific literature. We identify important data gaps: CH4 and N2O emissions could be respectively 10–20 % higher than reported in EDGAR once all emissions are accounted. F-gas emissions estimates for individual species in EDGARv5 do not align well with atmospheric measurements and the F-gas total exceeds measured concentrations by about 30 %. However, EDGAR and official national emission reports under the UNFCCC do not comprehensively cover all relevant F-gas species. Excluded F-gas species such as chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs) are larger than the sum of the reported species. GHG emissions in 2019 amounted to 59 ± 6.6 GtCO2eq: CO2 emissions from FFI were 38 ± 3.0 Gt, CO2 from LULUCF 6.6 ± 4.6 Gt, CH4 11 ± 3.3 GtCO2eq, N2O 2.4 ±1.5 GtCO2eq and F-gases 1.6 ± 0.49 GtCO2eq. Our analysis of global, anthropogenic GHG emission trends over the past five decades (1970–2019) highlights a pattern of varied, but sustained emissions growth. There is high confidence that global anthropogenic greenhouse gas emissions have increased every decade. Emission growth has been persistent across different (groups of) gases. While CO2 has accounted for almost 75 % of the emission growth since 1970 in terms of CO2eq as reported here, the combined F-gases have grown at a faster rate than other GHGs, albeit starting from low levels in 1970. Today, F-gases make a non-negligible contribution to global warming – even though CFCs and HCFCs, regulated under the Montreal Protocol and not included in our estimates, have contributed more. There is further high confidence that global anthropogenic GHG emission levels were higher in 2010-2019 than in any previous decade and GHG emission levels have grown across the most recent decade. While average annual greenhouse gas emissions growth slowed between 2010–2019 compared to 2000–2009, the absolute increase in average decadal GHG emissions from the 2000s to the 2010s has been the largest since the 1970s – and within all human history as suggested by available long-term data. We note considerably higher rates of change in GHG emissions between 2018 and 2019 than for the entire decade 2010–2019, which is numerically comparable with the period of high GHG emissions growth during the 2000s, but we place low confidence in this finding as the majority of the growth is driven by highly uncertain increases in CO2-LULUCF emissions as well as the use of preliminary data and extrapolation methodologies for these most recent years. While there is a growing number of countries today on a sustained emission reduction trajectory, our analysis further reveals that there are no global sectors that show sustained reductions in GHG emissions. We conclude by highlighting that tracking progress in climate policy requires substantial investments in independent GHG emission accounting and monitoring as well as the available national and international statistical infrastructures. The data associated with this article (Minx et al. 2021) can be found at https://doi.org/10.5281/zenodo.5053056.

Meeting human needs at sustainable levels of energy use is fundamental for avoiding catastrophic climate change and securing the well-being of all people. In the current political-economic regime, no country does so. Here, we assess which socio-economic conditions might enable societies to satisfy human needs at low energy use, to reconcile human well-being with climate mitigation. Using a novel analytical framework alongside a novel multivariate regression-based moderation approach and data for 106 countries, we analyse how the relationship between energy use and six dimensions of human need satisfaction varies with a wide range of socio-economic factors relevant to the provisioning of goods and services ('provisioning factors'). We find that factors such as public service quality, income equality, democracy, and electricity access are associated with higher need satisfaction and lower energy requirements (‘beneficial provisioning factors’). Conversely, extractivism and economic growth beyond moderate levels of affluence are associated with lower need satisfaction and greater energy requirements (‘detrimental provisioning factors’). Our results suggest that improving beneficial provisioning factors and abandoning detrimental ones could enable countries to provide sufficient need satisfaction at much lower, ecologically sustainable levels of energy use. However, as key pillars of the required changes in provisioning run contrary to the dominant political-economic regime, a broader transformation of the economic system may be required to prioritise, and organise provisioning for, the satisfaction of human needs at low energy use.

Meeting human needs at low levels of energy use is fundamental for avoiding catastrophic climate change and securing the well-being of all people. In the current international political-economic regime, no country does so.Here, we assess which socio-economic conditions might enable societies to satisfy human needs at sustainable levels of energy use, and thus reconcile human well-being with ambitious climate mitigation. Applying a novel analytical framework and a novel regression-based moderation approach to data from 106 countries, we analyse how the relationship between energy use and six dimensions of human need satisfaction varies with a wide range of socio-economic factors relevant to the provisioning of goods and services (‘provisioning factors’).We find that higher achievements in provisioning factors such as income equality, public service quality, democracy and electricity access are associated with greater need satisfaction and lower energy dependence of need satisfaction. Conversely, higher levels of economic growth and extractivism are associated with lower need satisfaction and greater energy dependence of need satisfaction. Our analysis suggests that countries with beneficial configurations of key provisioning factors are much more likely to reach high levels of need satisfaction at low(er) levels of energy use. Based on our statistical models, countries with highly beneficial configurations of several key provisioning factors could likely achieve sufficient need satisfaction within levels of energy use found compatible with limiting global warming to 1.5 °C without negative emissions technologies. Achieving this would be very unlikely for countries with detrimental provisioning configurations.Improvements in relevant provisioning factors may thus be crucial for ending human deprivation in currently underproviding countries without exacerbating climate and ecological crises, and for tackling the ecological overshoot of currently needs-satisfying countries without compromising sufficient need satisfaction. However, as key pillars of the suggested changes in provisioning run contrary to the dominant political-economic regime, a broader political-economic transformation may be required to organise provisioning for the satisfaction of human needs within sustainable levels of energy use.Our findings have important implications for climate mitigation, poverty eradication, development discourses, and efforts towards Sustainable Development Goals and socio-ecological transformation.

As current action remains insufficient to meet the goals of the Paris agreement let alone to stabilize the climate, there is increasing hope that solutions related to demand, services and social aspects of climate change mitigation can close the gap. However, given these topics are not investigated by a single epistemic community, the literature base underpinning the associated research continues to be undefined. Here, we aim to delineate a plausible body of literature capturing a comprehensive spectrum of demand, services and social aspects of climate change mitigation. As method we use a novel double-stacked expert—machine learning research architecture and expert evaluation to develop a typology and map key messages relevant for climate change mitigation within this body of literature. First, relying on the official key words provided to the Intergovernmental Panel on Climate Change by governments (across 17 queries), and on specific investigations of domain experts (27 queries), we identify 121 165 non-unique and 99 065 unique academic publications covering issues relevant for demand-side mitigation. Second, we identify a literature typology with four key clusters: policy, housing, mobility, and food/consumption. Third, we systematically extract key content-based insights finding that the housing literature emphasizes social and collective action, whereas the food/consumption literatures highlight behavioral change, but insights also demonstrate the dynamic relationship between behavioral change and social norms. All clusters point to the possibility of improved public health as a result of demand-side solutions. The centrality of the policy cluster suggests that political actions are what bring the different specific approaches together. Fourth, by mapping the underlying epistemic communities we find that researchers are already highly interconnected, glued together by common interests in sustainability and energy demand. We conclude by outlining avenues for interdisciplinary collaboration, synthetic analysis, community building, and by suggesting next steps for evaluating this body of literature.

In this article, we explore the concept of consumption corridors as it might apply to energy use, with specific attention to both wellbeing and power relations. We employ the distinction between energy provisioning and human-need satisfaction to explore different configurations of energy use, as well as their possible dynamics. Specifically, we draw on past research documenting the benefits of decoupling our thinking about energy services and needs satisfaction and use it as a basis to identify scenarios characterized by different degrees of access to energy services and levels of resource demand. We then translate this perspective to the logic of sustainable consumption corridors. We delineate how minimum and maximum consumption standards would relate to combinations of energy-service demand and needs-satisfier access. Finally, we explore how power dynamics, specifically exercises of discursive power, might move societal trajectories toward sustainable combinations of energy provisioning and needs satisfaction or away from them.

A rapid coal phase-out is needed to meet the goals of the Paris Agreement, but is hindered by serious challenges ranging from vested interests to the risks of social disruption. To understand how to organize a global coal phase-out, it is crucial to go beyond cost-effective climate mitigation scenarios and learn from the experience of previous coal transitions. Despite the relevance of the topic, evidence remains fragmented throughout different research fields, and not easily accessible. To address this gap, this paper provides a systematic map and comprehensive review of the literature on historical coal transitions. We use computer-assisted systematic mapping and review methods to chart and evaluate the available evidence on historical declines in coal production and consumption. We extracted a dataset of 278 case studies from 194 publications, covering coal transitions in 44 countries and ranging from the end of the 19th century until 2021. We find a relatively recent and rapidly expanding body of literature reflecting the growing importance of an early coal phase-out in scientific and political debates. Previous evidence has primarily focused on the United Kingdom, the United States, and Germany, while other countries that experienced large coal declines, like those in Eastern Europe, are strongly underrepresented. An increasing number of studies, mostly published in the last 5 years, has been focusing on China. Most of the countries successfully reducing coal dependency have undergone both demand-side and supply-side transitions. This supports the use of policy approaches targeting both demand and supply to achieve a complete coal phase-out. From a political economy perspective, our dataset highlights that most transitions are driven by rising production costs for coal, falling prices for alternative energies, or local environmental concerns, especially regarding air pollution. The main challenges for coal-dependent regions are structural change transformations, in particular for industry and labor. Rising unemployment is the most largely documented outcome in the sample. Policymakers at multiple levels are instrumental in facilitating coal transitions. They rely mainly on regulatory instruments to foster the transitions and compensation schemes or investment plans to deal with their transformative processes. Even though many models suggest that coal phase-outs are among the low-hanging fruits on the way to climate neutrality and meeting the international climate goals, our case studies analysis highlights the intricate political economy at work that needs to be addressed through well-designed and just policies.

Contemporary consumption patterns, embedded in profit-maximizing economic systems, are driving a worsening socio-ecological crisis, in particular through the escalating production and consumption of goods with high material and/or energy intensity. Establishing minimum and maximum standards of consumption (or “consumption corridors”) has been suggested as a way to address this crisis. Consumption corridors provide the normative basis for sustainable consumption, that is, enough consumption for individuals to satisfy needs, but not too much to collectively surpass environmental limits. Current consumption patterns (especially in the global North) do not yet fall within consumption corridors, and standards are not fixed over time. Consumption is socially constructed and can escalate due to socio-economic, technological, or infrastructural influences. In this article, we propose a framework to understand such escalating trends. This approach can be used as a tool for comprehending how consumption evolves over time, as well as for identifying the most effective leverage points to intervene and prevent escalation from happening in the first place. We build on theories of human-need satisfaction and combine these conceptual understandings with insights from research on socio-technical provisioning systems, sociological approaches to consumption, and perspectives on infrastructure lock-in. We illustrate our framework by systemically considering escalation for a specific technological product – the private car.

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It is critical to ensure climate and energy policies are just, equitable and beneficial for communities, both to sustain public support for decarbonisation and address multifaceted societal challenges. Our objective in this article is to examine the diverse social outcomes that have resulted from climate policies, in varying contexts worldwide, over the past few decades. We review 203 ex-post climate policy assessments that analyse social outcomes in the literature. We systematically and comprehensively map out this work, identifying articles on carbon, energy and transport taxes, feed-in-tariffs, subsidies, direct procurement policies, large renewable deployment projects, and other regulatory and market-based interventions. We code each article in terms of their studied social outcomes and effects, with a focus on electricity access, energy affordability, community cohesion, employment, distributional and equity issues, livelihoods and poverty, procedural justice, subjective well-being and drudgery. Our analysis finds that climate and energy policies often fall short of delivering positive social outcomes. Nonetheless, across country contexts and policy types there are manifold examples of climate policymaking that does deliver on both social and climate goals. This requires attending to distributive and procedural justice in policy design, and making use of appropriate mechanisms to ensure that policy costs and benefits are fairly shared. We emphasize the need to further advance ex-post policy assessments and learn about what policies work for a just transition.

The volume of published academic research is growing rapidly and this new era of “big literature” poses new challenges to evidence synthesis, pushing traditional, manual methods of evidence synthesis to their limits. New technology developments, including machine learning, are likely to provide solutions to the problem of information overload and allow scaling of systematic maps to large and even vast literatures. In this paper, we outline how systematic maps lend themselves well to automation and computer‐assistance. We believe that it is a major priority to consolidate efforts to develop and validate efficient, rigorous and robust applications of these novel technologies, ensuring the challenges of big literature do not prevent the future production of systematic maps.

Should economic growth continue in a world threatened by the prospect of catastrophic climate change? The scientific and public debate has brought forth a broad spectrum of views and narratives on this question, ranging from neoclassical economics to degrowth. We argue that different positions can be attributed to underlying differences in views on (a) factors that determine human well‐being, (b) the feasibility and desirability of economic growth, (c) appropriate intervention points, and (d) preferences about governance and policy options. For each of these dimensions, we propose points of agreement on which a consensus between conflicting positions might be achieved. From this basis, we distill a sustainability transition perspective that could act as a basis for a renewed debate on how to align human well‐being with environmental sustainability. This article is categorized under: Climate Economics>Economics and Climate Change

Non-technical summary ‘Discourses of climate delay’ pervade current debates on climate action. These discourses accept the existence of climate change, but justify inaction or inadequate efforts. In contemporary discussions on what actions should be taken, by whom and how fast, proponents of climate delay would argue for minimal action or action taken by others. They focus attention on the negative social effects of climate policies and raise doubt that mitigation is possible. Here, we outline the common features of climate delay discourses and provide a guide to identifying them.

Research on climate change mitigation tends to focus on supply-side technology solutions. A better understanding of demand-side solutions is missing. We propose a transdisciplinary approach to identify demand-side climate solutions, investigate their mitigation potential, detail policy measures and assess their implications for well-being.

Cities are key for achieving the 1.5 °C warming limit of the Paris Agreement. However, synthesizing policy insights from the urban literature is a challenge, due to its rapid growth, breadth of topics and relative lack of assessments so far. Here we introduce methods from computational linguistics to build a systematic overview of research on transport, buildings, waste management and urban form. We find that the epistemic core of the mitigation-focused urban literature is currently centered on urban form and emissions accounting, while extensive research into demand-side options remain overlooked, including congestion and parking polices, active travel, and waste management. In the IPCC Special Report on 1.5 °C, and for meeting the target itself, all such city-scale opportunities need to be examined.

There has been much debate about the assessment process of the Intergovernmental Panel on Climate Change (IPCC). Yet two of the most fundamental challenges that directly threaten the ability of the IPCC to fulfill its mandate have been largely neglected so far. Firstly, the magnitude and rapid expansion of the climate change literature makes it increasingly impossible for the IPCC to conduct comprehensive and transparent assessments without major innovations in assessment practices and tools. Secondly, the structure, organization and scientific practices across the social sciences and humanities prohibit systematic learning on climate change solutions and increasingly limit the policy-relevance of IPCC assessments. We highlight the need for responses along three avenues to prepare the IPCC for continued success in the future: 1) IPCC assessments must make better use of big-data methods and available computational power to assess the growing body of literature and ensure comprehensiveness; 2) systematic review practices need to be enshrined into IPCC procedures to ensure adequate focus and transparency in its assessments; 3) a synthetic research culture needs to be established in the social sciences and humanities in order to foster knowledge accumulation and learning on climate solutions in the future. As policymakers become more interested in understanding solutions, the future prospects of global environmental assessment enterprises will depend heavily on a successful transformation within the social sciences and humanities towards systematic knowledge generation. This article is part of a special issue on solution-oriented Global Environmental Assessments.

Non-technical abstract The climate crisis requires nations to achieve human well-being with low national levels of carbon emissions. Countries vary from one another dramatically in how effectively they convert resources into well-being, and some nations with low levels of emissions have relatively high objective and subjective well-being. We identify urgent research and policy agendas for four groups of countries with either low or high emissions and well-being indicators. Least studied are those with low well-being and high emissions. Understanding social and political barriers to switching from high-carbon to lower-carbon modes of production and consumption, and ways to overcome them, will be fundamental.

Climate policy advice is being undermined by value-laden choices over risky mitigation strategies, warn Dominic Lenzi and colleagues. Climate policy advice is being undermined by value-laden choices over risky mitigation strategies, warn Dominic Lenzi and colleagues.

Global greenhouse gas (GHG) emissions can be traced to five economic sectors: energy, industry, buildings, transport and AFOLU (agriculture, forestry and other land uses). In this topical review, we synthesise the literature to explain recent trends in global and regional emissions in each of these sectors. To contextualise our review, we present estimates of GHG emissions trends by sector from 1990 to 2018, describing the major sources of emissions growth, stability and decline across ten global regions. Overall, the literature and data emphasise that progress towards reducing GHG emissions has been limited. The prominent global pattern is a continuation of underlying drivers with few signs of emerging limits to demand, nor of a deep shift towards the delivery of low and zero carbon services across sectors. We observe a moderate decarbonisation of energy systems in Europe and North America, driven by fuel switching and the increasing penetration of renewables. By contrast, in rapidly industrialising regions, fossil-based energy systems have continuously expanded, only very recently slowing down in their growth. Strong demand for materials, floor area, energy services and travel have driven emissions growth in the industry, buildings and transport sectors, particularly in Eastern Asia, Southern Asia and South-East Asia. An expansion of agriculture into carbon-dense tropical forest areas has driven recent increases in AFOLU emissions in Latin America, South-East Asia and Africa. Identifying, understanding, and tackling the most persistent and climate-damaging trends across sectors is a fundamental concern for research and policy as humanity treads deeper into the Anthropocene.

This paper explores the underlying development outcomes and cumulative emissions trajectories of 20 middle-income countries from Eastern Europe, Latin America, North Africa and South Asia. First, well-being outcomes are assessed, defined in terms of access to education, democratic and legal rights, and the infrastructures that support physical health. Second, emissions trajectories are estimated to 2050, taking into account current trends in energy consumption and carbon intensity, a likely start-date for stringent climate policy arising from the Paris Agreement (2020), and maximum feasible rates of mitigation. Comparing these estimates to a per capita allocation from the global carbon budget associated with 2 °C, ten countries have low-carbon development trends that will not exceed their allocation. Of these, Costa Rica and Uruguay are achieving very high well-being outcomes, while many more are delivering good outcomes in at least two domains of human need. However, most are seriously deficient in terms of social well-being (education, democratic and legal rights). These results call into question the socio-economic convergence of developing countries with industrialised countries; but they also reaffirm the low-emissions cost of extending good infrastructure access and physical health outcomes to all, demonstrated by the existence of multiple countries that continue to avoid carbon-intensive development.

A growing number of researchers and stakeholders have started to address climate change from the bottom up: by devising scientific models, climate plans, low-carbon strategies and development policies with climate co-benefits. Little is known about the comparative characteristics of these interventions, including their relative efficacy, potentials and emissions reductions. A more systematic understanding is required to delineate the urban mitigation space and inform decision-making. Here, we utilize bibliometric methods and machine learning to meta-analyze 5635 urban case studies of climate change mitigation. We identify 867 studies that explicitly consider technological or policy instruments, and categorize these studies according to policy type, sector, abatement potential, and socio-technological composition to obtain a first heuristic of what is their pattern. Overall, we find 41 different urban solutions with an average GHG abatement potential ranging from 5.2% to 105%, most of them clustering in the building and transport sectors. More than three-fourth of the solutions are on demand side. Less than 10% of all studies were ex-post policy evaluations. Our results demonstrate that technology-oriented interventions in urban waste, transport and energy sectors have the highest marginal abatement potential, while system-wide interventions, e.g. urban form related measures have lower marginal abatement potential but wider scope. We also demonstrate that integrating measures across urban sectors realizes synergies in GHG emission reductions. Our results reveal a rich evidence of techno-policy choices that together enlarge the urban solutions space and augment actions currently considered in global assessments of climate mitigation.

The Paris Agreement (PA) sets out to strengthen the global response to climate change, setting targets for mitigation, adaptation, and finance, and establishing mechanisms through which to achieve these targets. The effectiveness of the PA’s mechanisms in achieving its targets, however, has been questioned. This review systematically maps the peer-reviewed literature on the PA, categorizing the available evidence on whether or not the ‘Paris Regime’ can be effective. We split our analysis into three methodologically distinct sections: first we categorize the literature according to the mechanisms being studied. We find a diverse body of literature, albeit with a clear focus on mitigation, and identify adaptation and capacity building to be clear gaps. Second, we carry out a content analysis, identifying common drivers of, barriers to, and recommendations for effectiveness. Here we find mixed evidence, with potential drivers often qualified by more concrete barriers. Thirdly, we use scientometrics to identify six research clusters. These cover loss and damage, finance, legal issues, international politics, experimental evidence, and studies on tracking progress on the PA’s targets. We conclude with a narrative discussion of our findings, presenting three central themes. First, transparency is widely considered a precondition for the PA to be institutionally effective. However, a lack of clear reporting standards and comparable information renders the PA’s transparency provisions ineffective. Second, environmental effectiveness relies on national ambition, of which there is currently too little. It remains unclear to which extent the Paris Regime structure itself can induce significant ratcheting-up of ambition. Finally, the PA facilitates the diffusion of norms, enables learning and the sharing of best practices. This production of shared norms provides the most promising avenue for overcoming the current lack of ambition. One of the primary successes of the PA is in providing a platform for the exchange of experiences and ideas.

In the wake of the Paris Agreement, countries have yet to embark on deep decarbonisation pathways. This article explores the reasons for this limited response, taking a comparative political economy lens to identify national constraints that actively hinder climate policy progress. We discuss different metrics of climate policy progress, including emissions trends, climate legislation adoption, policy adoption, policy stringency, and policy outcomes. We then review literatures that explain varying national outcomes along these dimensions. Identified constraints include (but are not limited to) exposure to fossil fuel extraction activities, supply-side coal dependency, a lack of democratic norms, exposure to corruption, a lack of public climate awareness, and low levels of social trust. Correlation and principal component analysis of these variables demonstrates strong co-dependencies, including a North-South divide in institutional quality, trust and climate awareness that limits full participation in climate legislation and the removal of fossil subsidies. Recent trends indicate stability in corruption across the whole sample, and the continued durability of autocratic and extractivist states. We identify common constraints for five distinct country groups using cluster analysis: ‘oil & gas states’, ‘fragile states’, ‘coal-dependent development’, ‘fractured democracies’ and ‘wealthy OECD’. We highlight the need to scrutinise architectures of constraint – combinations of political economic factors that are mutually reinforcing and highly resistant to intervention.

The relationship between human health and well-being, energy use and carbon emissions is a foremost concern in sustainable development. If past advances in well-being have been accomplished only through increases in energy use, there may be significant trade-offs between achieving universal human development and mitigating climate change. We test the explanatory power of economic, dietary and modern energy factors in accounting for past improvements in life expectancy, using a simple novel method, functional dynamic decomposition. We elucidate the paradox that a strong correlation between emissions and human development at one point in time does not imply that their dynamics are coupled in the long term. Increases in primary energy and carbon emissions can account for only a quarter of improvements in life expectancy, but are closely tied to growth in income. Facing this carbon-development paradox requires prioritizing human well-being over economic growth.

With the Paris Agreement's ambition of limiting climate change to well below 2 °C, negative emission technologies (NETs) have moved into the limelight of discussions in climate science and policy. Despite several assessments, the current knowledge on NETs is still diffuse and incomplete, but also growing fast. Here, we synthesize a comprehensive body of NETs literature, using scientometric tools and performing an in-depth assessment of the quantitative and qualitative evidence therein. We clarify the role of NETs in climate change mitigation scenarios, their ethical implications, as well as the challenges involved in bringing the various NETs to the market and scaling them up in time. There are six major findings arising from our assessment: first, keeping warming below 1.5 °C requires the large-scale deployment of NETs, but this dependency can still be kept to a minimum for the 2 °C warming limit. Second, accounting for economic and biophysical limits, we identify relevant potentials for all NETs except ocean fertilization. Third, any single NET is unlikely to sustainably achieve the large NETs deployment observed in many 1.5 °C and 2 °C mitigation scenarios. Yet, portfolios of multiple NETs, each deployed at modest scales, could be invaluable for reaching the climate goals. Fourth, a substantial gap exists between the upscaling and rapid diffusion of NETs implied in scenarios and progress in actual innovation and deployment. If NETs are required at the scales currently discussed, the resulting urgency of implementation is currently neither reflected in science nor policy. Fifth, NETs face severe barriers to implementation and are only weakly incentivized so far. Finally, we identify distinct ethical discourses relevant for NETs, but highlight the need to root them firmly in the available evidence in order to render such discussions relevant in practice., Environmental Research Letters, 13 (6), ISSN:1748-9326, ISSN:1748-9318

We assess the literature on innovation and upscaling for negative emissions technologies (NETs) using a systematic and reproducible literature coding procedure. To structure our review, we employ the framework of sequential stages in the innovation process, with which we code each NETs article in innovation space. We find that while there is a growing body of innovation literature on NETs, 59% of the articles are focused on the earliest stages of the innovation process, 'research and development' (R&D). The subsequent stages of innovation are also represented in the literature, but at much lower levels of activity than R&D. Distinguishing between innovation stages that are related to the supply of the technology (R&D, demonstrations, scale up) and demand for the technology (demand pull, niche markets, public acceptance), we find an overwhelming emphasis (83%) on the supply side. BECCS articles have an above average share of demand-side articles while direct air carbon capture and storage has a very low share. Innovation in NETs has much to learn from successfully diffused technologies; appealing to heterogeneous users, managing policy risk, as well as understanding and addressing public concerns are all crucial yet not well represented in the extant literature. Results from integrated assessment models show that while NETs play a key role in the second half of the 21st century for 1.5 degrees C and 2 degrees C scenarios, the major period of new NETs deployment is between 2030 and 2050. Given that the broader innovation literature consistently finds long time periods involved in scaling up and deploying novel technologies, there is an urgency to developing NETs that is largely unappreciated. This challenge is exacerbated by the thousands to millions of actors that potentially need to adopt these technologies for them to achieve planetary scale. This urgency is reflected neither in the Paris Agreement nor in most of the literature we review here. If NETs are to be deployed at the levels required to meet 1.5 degrees C and 2 degrees C targets, then important post-R&D issues will need to be addressed in the literature, including incentives for early deployment, niche markets, scale-up, demand, and-particularly if deployment is to be hastened-public acceptance.

Humanity faces the challenge of how to achieve a high quality of life for over 7 billion people without destabilizing critical planetary processes. Using indicators designed to measure a ‘safe and just’ development space, we quantify the resource use associated with meeting basic human needs, and compare this to downscaled planetary boundaries for over 150 nations. We find that no country meets basic needs for its citizens at a globally sustainable level of resource use. Physical needs such as nutrition, sanitation, access to electricity and the elimination of extreme poverty could likely be met for all people without transgressing planetary boundaries. However, the universal achievement of more qualitative goals (for example, high life satisfaction) would require a level of resource use that is 2–6 times the sustainable level, based on current relationships. Strategies to improve physical and social provisioning systems, with a focus on sufficiency and equity, have the potential to move nations towards sustainability, but the challenge remains substantial.

Generating negative emissions by removing carbon dioxide from the atmosphere is a key requirement for limiting global warming to well below 2 °C, or even 1.5 °C, and therefore for achieving the long-term climate goals of the recent Paris Agreement. Despite being a relatively young topic, negative emission technologies (NETs) have attracted growing attention in climate change research over the last decade. A sizeable body of evidence on NETs has accumulated across different fields that is by today too large and too diverse to be comprehensively tracked by individuals. Yet, understanding the size, composition and thematic structure of this literature corpus is a crucial pre-condition for effective scientific assessments of NETs as, for example, required for the new special report on the 1.5 °C by the Intergovernmental Panel on Climate Change (IPCC). In this paper we use scientometric methods and topic modelling to identify and characterize the available evidence on NETs as recorded in the Web of Science. We find that the development of the literature on NETs has started later than for climate change as a whole, but proceeds more quickly by now. A total number of about 2900 studies have accumulated between 1991 and 2016 with almost 500 new publications in 2016. The discourse on NETs takes place in distinct communities around energy systems, forests as well as biochar and other soil carbon options. Integrated analysis of NET portfolios—though crucial for understanding how much NETs are possible at what costs and risks—are still in their infancy and do not feature as a theme across the literature corpus. Overall, our analysis suggests that NETs research is relatively marginal in the wider climate change discourse despite its importance for global climate policy.

Generally speaking, the judicial proceedings spawned by the corruption of the 1919 World Series are not accurately related or well understood in the Black Sox canon. In a forthcoming book to be published by McFarland, the writer will attempt to remedy this situation by offering a comprehensive, non-partisan factual account of Black Sox- related grand jury proceedings, the Black Sox criminal trial, and ensuing civil litigation involving scandal principals. Legal analysis will also be provided on certain aspects of these actions. This article is drawn from that work and recounts events attending late-September 1920 grand jury hearings, focusing on a four-day period when the simmering Black Sox scandal finally exploded. An introductory summary of preceding scandal developments is designed to place the article's narrative in perspective.Preceding Scandal DevelopmentsSuspicions about the bona fides of Chisox play were raised in post-1919 World Series columns by syndicated sportswriter Hugh F. Fullerton and a few other scribes.1 But for the most part, sportswriter concerns did not generate great public interest and the matter had become mostly forgotten by the time that the 1920 season commenced. Rather, the exposure of the Black Sox scandal was largely a byproduct of investigation of an altogether different Chicago baseball contretemps: the alleged fixing of a meaningless August 31, 1920 game between the Cubs and the Philadelphia Phillies. Shortly after the existence of an internal investigation of the contest was revealed by Cubs President William L. Veeck, Sr., the judiciary stepped in. On September 7, 1920, the suspect game was brought to the attention of a Cook County grand jury by Illinois Circuit Court Judge Charles A. McDonald, newly appointed chief justice of the local criminal courts and an avid Chicago baseball fan.2 In time, the scope of the grand jury's probe expanded into other matters: game-related skullduggery attributed to Hal Chase, the operation of baseball betting pools in the greater Chicago area, and the rumored fixing of the 1919 World Series.Early proceedings were slow-moving and unfocused but gathered steam following testimony about the alleged Series fix from White Sox owner Charles Comiskey, Chicago Tribune sportswriter James Crusinberry, and New York Giants pitcher and Chase teammate Rube Benton, all of which was immediately leaked to the press. Probe developments were also supplied by lead grand jury prosecutor Hartley Replogle and grand jury foreman Henry H. Brigham, both of whom spoke openly about matters revealed during the proceedings. All of this was highly irregular, if not unlawful. By statute and case law, grand jury proceedings are strictly confidential and proceeding principals, like the prosecutor and panel members, take an oath to keep grand jury testimony and other proof secret.3 Stranger still, this disregard of grand jury protocol appeared countenanced by Judge McDonald. According to one report, "officials of Chief Justice Charles McDonald's court, desirous of giving the national game the benefit of publicity in its purging, lifted the curtain on the grand jury proceeding." 4 By September 25, the transparency of grand jury proceedings permitted press publication of the names of eight White Sox players believed targeted for indictment- Eddie Cicotte, Chick Gandil, Lefty Williams, Swede Risberg, Happy Felsch, Joe Jackson, Fred McMullin, and Buck Weaver-and the nature of the charge likely to be preferred against them: conspiracy to defraud.5 But details of the series fix as well as the roles of the accused players in it remained unsettled. That would change two days later, for in Philadelphia, a figure from baseball's margins was giving the interview that would blow open the corruption of the 1919 World Series.Publication of the Billy Maharg StoryOn September 27, 1920, sportswriter James Isaminger provided readers of the Philadelphia North American with the first insider's account of the abasement of the 1919 Series. …

Quietly nestled among the renowned sports names charged in the Black Sox scandal is that of an obscure figure: one Rachael Brown.1 Based on surviving evidence, it appears that Brown was indicted by the Cook County grand jury almost entirely on the word of Lefty Williams, who identified the negotiators of the fix as "two fellows introduced as Brown and Sullivan ... the gamblers from New York."2 Defendant Brown, however, was never taken into custody on the indictment. Nor did he ever make an appearance, either personally or via counsel, in a Chicago courtroom. From the time of the scandal until today, Rachael Brown has remained largely a cipher, a scandal actor whose identity has never been conclusively established. In the order in which they appeared on the public stage, here are snapshots of the most likely candidates for the role of Black Sox defendant Rachael Brown.1. Abram Braunstein, Commonly Known as Rachel BrownA contemporary of Arnold Rothstein, Abram "Rachel" Braunstein was a smalltime Manhattan gambler who first came to public attention via his connection to Louis "Bridgie" Webber, a key prosecution witness in the trial of the notorious Rosenthal murder case. Those proceedings culminated in conviction with death sentences for five men, including corrupt NYPD Vice Squad Lieutenant Charles Becker. While in a jail cell awaiting his fate, Becker claimed that Rosenthal's killers had had an earlier target, namely "'Rachel' Braunstein, Webber's partner in a 42nd Street gambling house and known in the gambling fraternity as Rachel Brown."3 According to Becker, a prospective new trial witness named Jack Sullivan would testify that Rosenthal's slayers had plotted to kill Rachel Braunstein and take his half of the gambling partnership. Sullivan "learned of it ... told Braunstein and escorted him to a steamship" on which Braunstein escaped to Spain, as reported in the Boston Globe, The New York Times, the New Brunswick (N.J.) Times, and the Washington Post, Oct. 29, 1912. In due course, this allegation precipitated the issuance of a subpoena for "Rachel Brown of 123 Manhattan Avenue," served while Brown was appearing in magistrate's court to answer a disorderly conduct charge that stemmed from a fight. Indignant, Brown disclaimed knowledge of the reason why the subpoena had been issued and "asserted that since the Becker trial he had been hounded and threatened on many occasions," as per The New York Times, Mar. 6, 1914.After that, Brown apparently tried to stay out of the public eye. But four years later, "Rachie Brown, the old partner of Bridgie Webber" was back in the news after being netted in a police raid of the newly opened Picadilly Club in Manhattan. The arrestee identified himself as fish dealer Aaron Braun but vice detectives immediately recognized him as "the genuine 'Rachie Brown'" (Boston Globe, Dec. 9, 1918). The following summer, Brown was in custody again, arrested during a raid on a disreputable gambling resort in Saratoga, as reported in the Saratogian, Jul. 29, 1919. After much foot-dragging by local officials cozy with gaming interests, a specially convened Saratoga County grand jury returned gambling-related indictments against 48 targets, including Abram (Rachie) Brown, as per the Saratoga Sun, Aug. 20, 1920.4None of the above received mention when newspapers nationwide ran stories about the forthcoming indictment of Joseph "Sport" Sullivan and Brown, "an otherwise unidentified gambler from New York City," in connection with the Cook County probe of the 1919 World Series (see, e.g., Chicago Tribune, Sept. 30, 1920). Within days, however, it was reported that "Rachie Brown, a gambler said to have been deeply involved in the Series plot, has left New York City and gone to Europe. His departure is regarded by underworld gossips as proof that he was mixed up in the baseball plot. He [Brown] had been known as a 'steerer' for Rothstein's gambling operations" (see unidentified news item reprinted in The Sporting News, Oct. …

The most recent IPCC assessment has shown an important role for negative emissions technologies (NETs) in limiting global warming to 2 °C cost-effectively. However, a bottom-up, systematic, reproducible, and transparent literature assessment of the different options to remove CO2 from the atmosphere is currently missing. In part 1 of this three-part review on NETs, we assemble a comprehensive set of the relevant literature so far published, focusing on seven technologies: bioenergy with carbon capture and storage (BECCS), afforestation and reforestation, direct air carbon capture and storage (DACCS), enhanced weathering, ocean fertilisation, biochar, and soil carbon sequestration. In this part, part 2 of the review, we present estimates of costs, potentials, and side-effects for these technologies, and qualify them with the authors' assessment. Part 3 reviews the innovation and scaling challenges that must be addressed to realise NETs deployment as a viable climate mitigation strategy. Based on a systematic review of the literature, our best estimates for sustainable global NET potentials in 2050 are 0.5–3.6 GtCO2 yr−1 for afforestation and reforestation, 0.5–5 GtCO2 yr−1 for BECCS, 0.5–2 GtCO2 yr−1 for biochar, 2–4 GtCO2 yr−1 for enhanced weathering, 0.5–5 GtCO2 yr−1 for DACCS, and up to 5 GtCO2 yr−1 for soil carbon sequestration. Costs vary widely across the technologies, as do their permanency and cumulative potentials beyond 2050. It is unlikely that a single NET will be able to sustainably meet the rates of carbon uptake described in integrated assessment pathways consistent with 1.5 °C of global warming., Environmental Research Letters, 13 (6), ISSN:1748-9326, ISSN:1748-9318