In pursuit of the drastic transformations necessary for effectively responding to climate change, the Paris Agreement stresses the need to design and implement sustainable, robust, and socially acceptable policy pathways in a globally coordinated and cooperative manner. For decades, the scientific community has been carrying out quantitative modelling exercises in support of climate policy design, primarily by means of energy systems and integrated assessment modelling frameworks. Here, we describe in detail the context of a hitherto ineffective scientific contribution to policymaking, highlight the available means to formulate a new paradigm that overcomes existing and emerging challenges, and ultimately call for change. In particular, we argue that individual modelling exercises alone widen the gap between formal representation and real-life context in which decisions are taken, and investigate major criticisms to which formalised modelling frameworks are subject. We essentially highlight the importance of employing diverse modelling ensembles, placing the human factor at the core of all modelling processes, and enhancing the robustness of model-driven policy prescriptions through decision support systems. These altogether compose a truly integrative approach to supporting the design of effective climate policy and sustainable transitions and, therefore, strengthen the modelling–policymaking interface.

Globalization of supply chains has resulted in rapid increases in emission transfers from the developing to the developed world. As outsourcing has risen, developed countries have been able to decarbonize domestically, at the expense of increased emissions in developing countries. However, the rapid improvement of carbon efficiency in developing regions together with the post-2008 deceleration in international trade raises the question of whether such embodied emission transfers have peaked. Here we update historical analysis, finding that emission transfers between OECD and non-OECD countries peaked in 2006, and have been declining since. The reversal is principally due to the reduction in the emissions intensity of traded goods, rather than the volume of trade. A more recent decline in embodied emissions transfers is also observed in trade between developing countries. We analyse whether these trends are likely to continue, by exploring a baseline and a Nationally Determined Contribution (NDC) scenario with the Macro-ejconometric Energy-Environment-Economy Model (E3ME) model. The results suggest that absolute embodied emissions will plateau at current levels or slowly return to pre-2008- crisis levels, and differences between the NDC and baseline scenarios imply that NDC policies will not result in significant carbon leakage. However, the share of national footprint embodied in imports, at least for countries with ambitious decarbonization policies, will likely increase. This suggests that, despite the world-wide stabilization of emissions transfers, addressing emissions embodied in imports will become increasingly important for reducing carbon footprints.

Transformation of economic systems is widely regarded as essential for tackling interacting global crises. Unconventional economic approaches seeking holistic human and planetary well-being have transformative potential, but mainstreaming them is hampered by vested interests and intellectual lock-ins. They are also diffuse and struggle to develop sufficient discursive power to gain more widespread traction in policy. To bring coherence, we undertake a qualitative content analysis of 238 document sources from science and practice. We identify ten ecological, social, political economy and holistic principles cutting across 38 economic approaches. They include: (1) social–ecological embeddedness and holistic well-being; (2) interdisciplinarity and complexity thinking; (3) limits to growth; (4) limited substitutability of natural capital; (5) regenerative design; (6) holistic perspectives of people and values; (7) equity, equality and justice; (8) relationality and social enfranchisement; (9) participation, deliberation and cooperation and (10) post-capitalism and decolonization. We also consider opportunities and barriers to applying these principles in the context of global crises. Our results can help consolidate transformative economic approaches and support future efforts to synthesize conceptual models, methodologies and policy solutions and to validate the identified principles more explicitly within global south contexts.

The recent IPCC Special Report on global warming of 1.5 °C emphasizes that rapid action to reduce greenhouse gas (GHG) emissions is vital to achieving the climate mitigation goals of the Paris Agreement. The most-needed substantial upscaling of investments in GHG mitigation options in all sectors, and particularly in manufacturing sectors, can be an opportunity for a green economic development leap in developing countries. Here, we use the Brazilian manufacturing sectors as an example to explore a transformation of its economy while contributing to the Paris targets. Projections of Brazil’s economic futures with and without a portfolio of fiscal policies to induce low carbon investments are produced up to 2030 (end year of Brazil’s Nationally Determined Contribution—NDC), by employing the large-scale macro econometric Energy-Environment-Economy Model, E3ME. Our findings highlight that the correct mix of green stimulus can help modernize and decarbonize the Brazilian manufacturing sectors and allow the country’s economy to grow faster (by up to 0.42% compared to baseline) while its carbon dioxide (CO₂) emissions decline (by up to 14.5% in relation to baseline). Investment levels increase, thereby strengthening exports’ competitiveness and alleviating external constraints to long-term economic growth in net terms.