[en] Ensuring the environmental integrity of internationally transferred mitigation outcomes, whether through offset arrangements, a market mechanism or non-market approaches, is a priority for the implementation of Article 6 of the Paris Agreement. Any conventional transferred mitigation outcome, such as an offset agreement, that involves exchanging greenhouse gases with different lifetimes can increase global warming on some timescales. We show that a simple ‘do no harm’ principle regarding the choice of metrics to use in such transactions can be used to guard against this, noting that it may also be applicable in other contexts such as voluntary and compliance carbon markets. We also show that both approximate and exact ‘warming equivalent’ exchanges are possible, but present challenges of implementation in any conventional market. Warming-equivalent emissions may, however, be useful in formulating warming budgets in a two-basket approach to mitigation and in reporting contributions to warming in the context of the global stocktake. (letter)

[en] While large companies routinely announce greenhouse gas emissions targets, few have derived targets based on global climate goals. This changed in 2015 with the creation of the science based targets (SBTs) initiative, which provides guidelines for setting emission targets in line with the temperature goal of the Paris Agreement. SBTs have now been set by more than 500 companies. Methods for setting such targets are not presented in a comparable way in target-setting guidelines and concerns that certain methods may lead to overshoot of the temperature goal have not been investigated. Here, we systematically characterize and compare all seven broadly applicable target-setting methods and quantify the balance between collective corporate SBTs and global allowable emissions for individual methods and different method mixes. We use a simplified global production scenario composed of eight archetypical companies to evaluate target-setting methods across a range of company characteristics and global emission scenarios. The methods vary greatly with respect to emission allocation principles, required company variables and embedded global emission scenarios. Some methods treat companies largely the same, while others differentiate between company types based on geography, economic sector, projected growth rate or baseline emission intensity. The application of individual target-setting methods as well as different mixes of methods tend to result in an imbalance between time-integrated aggregated SBTs and global allowable emissions. The sign and size of this imbalance is in some cases sensitive to the shape of the global emission pathway and the distribution of variables between the company archetypes. We recommend that the SBT initiative (a) use our SBT method characterisation to present methods in a systematic way, (b) consider our emission imbalance analysis in its method recommendations, (c) disclose underlying reasons for its method recommendations, and (d) require transparency from companies on the calculation of established SBTs. (letter)

[en] In Asia, much effort is put into reducing methane (CH₄) emissions due to the region’s contribution to the recent rapid global atmospheric CH₄ concentration growth. Accurate quantification of Asia’s CH₄ budgets is critical for conducting global stocktake and achieving the long-term temperature goal of the Paris Agreement. In this study, we present top-down estimates of CH₄ emissions from 2009 to 2018 deduced from atmospheric observations from surface network and GOSAT satellite with the high-resolution global inverse model NIES-TM-FLEXPART-VAR. The optimized average CH₄ budgets are 63.40 ± 10.52 Tg y⁻¹ from East Asia (EA), 45.20 ± 6.22 Tg y⁻¹ from Southeast Asia (SEA), and 64.35 ± 9.28 Tg y⁻¹ from South Asia (SA) within the 10 years. We analyzed two 5 years CH₄ emission budgets for three subregions and 13 top-emitting countries with an emission budget larger than 1 Tg y⁻¹, and interannual variabilities for these subregions. Statistically significant increasing trends in emissions are found in EA with a lower emission growth rate during 2014–2018 compared to that during 2009–2013, while trends in SEA are not significant. In contrast to the prior emission, the posterior emission shows a significant decreasing trend in SA. The flux decrease is associated with the transition from strong La Ninña (2010–2011) to strong El Ninño (2015–2016) events, which modulate the surface air temperature and rainfall patterns. The interannual variability in CH₄ flux anomalies was larger in SA compared to EA and SEA. The Southern Oscillation Index correlates strongly with interannual CH₄ flux anomalies for SA. Our findings suggest that the interannual variability in the total CH₄ flux is dominated by climate variability in SA. The contribution of climate variability driving interannual variability in natural and anthropogenic CH₄ emissions should be further quantified, especially for tropical countries. Accounting for climate variability may be necessary to improve anthropogenic emission inventories. (letter)

[en] Carbon dioxide removal from the atmosphere (CDR)—also known as ‘negative emissions’—features prominently in most 2 °C scenarios and has been under increased scrutiny by scientists, citizens, and policymakers. Critics argue that ‘negative emission technologies’ (NETs) are insufficiently mature to rely on them for climate stabilization. Some even argue that 2 °C is no longer feasible or might have unacceptable social and environmental costs. Nonetheless, the Paris Agreement endorsed an aspirational goal of limiting global warming to even lower levels, arguing that climate impacts—especially for vulnerable nations such as small island states—will be unacceptably severe in a 2 °C world. While there are few pathways to 2 °C that do not rely on negative emissions, 1.5 °C scenarios are barely conceivable without them. Building on previous assessments of NETs, we identify some urgent research needs to provide a more complete picture for reaching ambitious climate targets, and the role that NETs can play in reaching them. (letter)

[en] This report analyses how the role of sustainable development can be strengthened in the process of further designing the mechanisms under Article 6 of the Paris Agreement. The paper reflects on the experience with sustainable development in past and current market mechanisms and describes to what extent countries agreed on sustainable development issues in multilateral instruments and institutions outside the ⁠UNFCCC⁠. Based on the current negotiating draft texts (SBSTA 50 from June 2019, as well as CMA2 from December 2019), recommendations are put forward on how to anchor sustainable development and safeguarding provisions in the rules for Article 6.

[en] This paper examines the connection between Nationally Determined Contributions (NDCs) under the Paris Agreement on the one hand and carbon leakage on the other. Firstly, this is done by considering different types of emission targets in the NDCs. With an NDC in a carbon leakage receiving country, shifted emissions in many cases require increased mitigation efforts, so carbon leakage comes at a cost to these countries. Secondly, entrepreneurial decisions are examined more closely. The mere existence of NDCs should already have an influence on them, albeit not on immediate production decisions (production leakage), but on medium- and long-term investment decisions (investment leakage).

[en] The supposed demise of nuclear power has long been asserted by those opposed to the technology. But as the world struggles to meet the Paris Agreement climate goals of limiting global temperature increase by 1.5 °C to 2 °C compared to pre-industrial levels, neither the historic contribution nor the important future role of nuclear energy should be ignored. Nuclear is an indispensable tool to meet the dual challenge of meeting an increasing energy demand while phasing out fossil fuels. To paraphrase the speech of Robert Cecil at the final meeting of the League of Nations - nuclear power is dead, long live nuclear energy!

[en] Despite low per capita emissions, with over a billion population, India is pivotal for climate change mitigation globally, ranking as the third largest emitter of greenhouse gases. We linked a previously published multidimensional population projection with emission projections from an integrated assessment model to quantify the localised (i.e. state-level) health benefits from reduced ambient fine particulate matter in India under global climate change mitigation scenarios in line with the Paris Agreement targets and national scenarios for maximum feasible air quality control. We incorporated assumptions about future demographic, urbanisation and epidemiological trends and accounted for model feedbacks. Our results indicate that compared to a business-as-usual scenario, pursuit of aspirational climate change mitigation targets can avert up to 8.0 million premature deaths and add up to 0.7 years to life expectancy (LE) at birth due to cleaner air by 2050. Combining aggressive climate change mitigation efforts with maximum feasible air quality control can add 1.6 years to LE. Holding demographic change constant, we find that climate change mitigation and air quality control will contribute slightly more to increases in LE in urban areas than in rural areas and in states with lower socio-economic development. (letter)

[en] Highlights: • Energy policy increasingly takes account of the needs of commercial finance. • The multi-billion mobilisation of energy finance has significant justice impacts. • There are 6 principles of ‘just’ energy finance. • Energy policy focusses only on affordability, missing five remaining principles. Up to $61trillion of power systems investment is needed to fulfil the Paris Agreement. The mobilisation of so much capital is a huge challenge. As such, energy policy is changing to meet the needs of commercial finance. However, very little has been done to question the justice implications of this capital mobilisation, and what alternatives there are to commercially-oriented finance for low carbon energy systems. This paper uses a comparative analysis of two developed economies to explore how ‘alternative’ forms of finance operate in each nation’s energy investment landscape. We find alternative finance is often set in opposition to commercial capital. Alternative finance in both nations is motivated by financial justice outcomes that are poorly understood in current energy policy. Our findings suggest that 6 principles are key to ‘just’ energy finance: affordability, good governance, due process, intra-generational equity, spatial equity, and financial resilience. Energy policy that seeks to mobilise capital, should take account of all six principles.

[en] Carbon pricing has been hailed as an essential component of any sensible climate policy. Internalize the externalities, the logic goes, and polluters will change their behavior. The theory is elegant, but has carbon pricing worked in practice? Despite a voluminous literature on the topic, there are surprisingly few works that conduct an ex-post analysis, examining how carbon pricing has actually performed. This paper provides a meta-review of ex-post quantitative evaluations of carbon pricing policies around the world since 1990. Four findings stand out. First, though carbon pricing has dominated many political discussions of climate change, only 37 studies assess the actual effects of the policy on emissions reductions, and the vast majority of these are focused on Europe. Second, the majority of studies suggest that the aggregate reductions from carbon pricing on emissions are limited—generally between 0% and 2% per year. However, there is considerable variation across sectors. Third, in general, carbon taxes perform better than emissions trading schemes (ETSs). Finally, studies of the EU-ETS, the oldest ETS, indicate limited average annual reductions—ranging from 0% to 1.5% per annum. For comparison, the IPCC states that emissions must fall by 45% below 2010 levels by 2030 in order to limit warming to 1.5 °C—the goal set by the Paris Agreement (Intergovernmental Panel on Climate Change 2018). Overall, the evidence indicates that carbon pricing has a limited impact on emissions. (topical review)