Most of the integrated assessment modelling (IAM) literature focuses on cost-effective pathways towards given temperature goals. Conversely, using seven diverse IAMs we project global energy CO 2 emissions trajectories based on near-term mitigation efforts, and two assumptions on how these efforts continue post-2030. Despite finding a wide range of emissions by 2050, nearly all the scenarios have median warming of less than 3°C in 2100. However, the most optimistic scenario is still insufficient to limit global warming to 2°C. We furthermore highlight key modelling choices inherent to projecting where emissions are headed. First, emissions are more sensitive to the choice of IAM than to the assumed mitigation effort, highlighting the importance of heterogenous model intercomparisons. Differences across models reflect diversity in baseline assumptions and impacts of near-term mitigation efforts. Second, common practice of using economy-wide carbon prices to represent policy exaggerates carbon capture and storage (CCS) use compared to explicitly modelling policies. Ed Summ 2Mitigation pathways tend to focus on an end temperature target and calculate how to keep within these bounds. This work uses seven integrated assessment models to consider current mitigation efforts, and project likely temperature trajectories.

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The paper analyses the synergies and trade-offs between emission reduction policies and sustainable development objectives. Specifically, it provides an ex-ante assessment that the impacts of the Nationally Determined Contributions (NDCs), submitted under the Paris Agreement, will have on the Sustainable Development Goals (SDGs) of poverty eradication (SDG1) and reduced income inequality (SDG10). By combining an empirical analysis with a modelling exercise, the paper estimates the future trends of poverty prevalence and inequality across countries in a reference scenario and under a climate mitigation policy with alternative revenue recycling schemes. Our results suggest that a full implementation of the emission reduction contributions, stated in the NDCs, is projected to slow down the effort to reduce poverty by 2030 (+2% of the population below the poverty line compared to the baseline scenario), especially in countries that have proposed relatively more stringent mitigation targets and suffer higher policy costs. Conversely, countries with a stringent mitigation policy experience a reduction of inequality compared to baseline scenario levels. If financial support for mitigation action in developing countries is provided through an international climate fund, the prevalence of poverty will be slightly reduced at the aggregate level (185,000 fewer poor people with respect to the mitigation scenario), but the country-specific effect depends on the relative size of funds flowing to beneficiary countries and on their economic structure.