[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 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] According to its article 2, the Paris Agreement PA aims at, inter alia, "Holding the increase in the global average temperature to well below 2 °C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5 °C above pre-industrial levels ... ". Paragraph 21 of the Decision, the document that explains the general thinking of the Parties to the United Nations Framework Convention on Climate Change UNFCCC as they adopted the PA in 2015, "Invites the Intergovernmental Panel on Climate Change [IPCC] to provide a special report in 2018 on the impacts of global warming of 1.5 °C above pre-industrial levels and related global greenhouse gas emission pathways."

[en] In June 2015, the G7 agreed to two global mitigation goals: ‘a decarbonization of the global economy over the course of this century’ and ‘the upper end of the latest Intergovernmental Panel on Climate Change (IPCC) recommendation of 40%–70% reductions by 2050 compared to 2010’. These IPCC recommendations aim to preserve a likely (>66%) chance of limiting global warming to 2 °C but are not necessarily consistent with the stronger ambition of the subsequent Paris Agreement of ‘holding the increase in the global average temperature to well below 2 °C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 °C above pre-industrial levels’. The G7 did not specify global or national emissions scenarios consistent with its own agreement. Here we identify global cost-optimal emissions scenarios from Integrated Assessment Models that match the G7 agreement. These scenarios have global 2030 emissions targets of 11%–43% below 2010, global net negative CO₂ emissions starting between 2056 and 2080, and some exhibit net negative greenhouse gas emissions from 2080 onwards. We allocate emissions from these global scenarios to countries according to five equity approaches representative of the five equity categories presented in the Fifth Assessment Report of the IPCC (IPCCAR5): ‘capability’, ‘equality’, ‘responsibility-capability-need’, ‘equal cumulative per capita’ and ‘staged approaches’. Our results show that G7 members’ Intended Nationally Determined Contribution (INDCs) mitigation targets are in line with a grandfathering approach but lack ambition to meet various visions of climate justice. The INDCs of China and Russia fall short of meeting the requirements of any allocation approach. Depending on how their INDCs are evaluated, the INDCs of India and Brazil can match some equity approaches evaluated in this study. (letter)

[en] Deployment potential for SMR Current nuclear plant designs on offer may be too large for several countries and regions, for reasons including: • cooling water requirements; • electrical grid size; • market demand; • financing requirements.

[en] This discussion paper explores key issues and options to achieve environmental integrity under Article 6 of the Paris Agreement. It proposes that environmental integrity in context of Article 6 means that using international transfers does not result in higher global GHG emissions than if mitigation targets of NDCs had been achieved only through domestic mitigation action. The paper identifies four issues that can affect the global GHG emissions outcome from international transfers: robust accounting for international transfers; the quality of units from mechanisms; the ambition of the NDC target of the transferring country; and presence of incentives and disincentives for further mitigation action. A particular risk is the international transfer of ''hot air''. Based on global GHG emissions and the communicated NDCs, it is estimated that global mitigation action be undermined by up to 68 % if all hot air in current NDCs would be transferred. The paper identifies and discusses seven options to mitigate environmental integrity risks from international transfers, including principles for international guidance on mechanism design and communication of NDCs, international reporting and review, eligibility criteria, limits on international transfers, exchange or discount rates, green investment schemes, and carbon clubs. Finally, the paper explores for crediting mechanisms how additionality could be demonstrated and how emission baselines could be set under the new framework of the Paris Agreement where nearly all Parties have communicated a mitigation target in their NDC.

[en] The potential role of nuclear energy in meeting the targets to limit global warming under the Paris Agreement on climate change depends primarily on what emissions reductions are needed. It is a two step process: we have to make sure that we are working with realistic targets before we can assess how nuclear can help.

[en] Since the ‘Paris agreement’ in 2015 there has been much focus on what a +1.5 °C or +2 °C warmer world would look like. Since the focus lies on policy relevant global warming targets, or specific warming levels (SWLs), rather than a specific point in time, projections are pooled together to form SWL ensembles based on the target temperature rather than emission scenario. This study uses an ensemble of CMIP5 global model projections to analyse how well SWL ensembles represent the stabilized climate of global warming targets. The results show that the SWL ensembles exhibit significant trends that reflect the transient nature of the RCP scenarios. These trends have clear effect on the timing and clustering of monthly cold and hot extremes, even though the effect on the temperature of the extreme months is less visible. In many regions there is a link between choice of RCP scenario used in the SWL ensemble and climate change signal in the highest monthly temperatures. In other regions there is no such clear-cut link. From this we conclude that comprehensive analyses of what prospects the different global warming targets bring about will require stabilization scenarios. Awaiting such targeted scenarios we suggest that prudent use of SWL scenarios, taking their characteristics and limitations into account, may serve as reasonable proxies in many situations. (letter)

[en] This event presented roadmaps for nuclear energy innovation linked to nationally determined contributions (NDCs) to the global response to climate change. It covered enabling conditions for research and development, the regulatory framework and infrastructure to support Member States’ NDC updates from 2020 to 2050

[en] • It is important to identify, understand and make use of all entry points and cooperation mechanisms for supporting those Parties willing to consider or strengthen nuclear power to address climate change. • IAEA and other organizations working on nuclear power should actively seek to contribute to the relevant processes under the Paris Agreement, including the global stockade. • The findings of this conference should be considered together with the findings of previous conferences on nuclear science and applications (e.g., contributions to adaptation and transformation in general).