Building equity in: strategies for integrating equity into modelling for a 1.5°C world.

Emission pathways consistent with limiting temperature increase to 1.5°C raise pressing questions from an equity perspective. These pathways would limit impacts and benefit vulnerable communities but also present trade-offs that could increase inequality. Meanwhile, rapid mitigation could exacerbate political debates in which equity has played a central role. In this paper, we first develop a set of elements we suggest are essential for evaluating the equity implications of policy actions consistent with 1.5°C. These elements include (i) assess climate impacts, adaptation, loss and damage; (ii) be sensitive to context; (iii) compare costs of mitigation and adaptation policy action; (iv) incorporate human development and poverty; (v) integrate inequality dynamics; and (vi) be clear about normative assumptions and responsive to users. We then assess the ability of current modelling practices to address each element, focusing on global integrated assessment models augmented by national modelling and scenarios. We find current practices face serious limitations across all six dimensions although the severity of these varies. Finally, based on our assessment we identify strategies that may be best suited for enabling us to generate insights into each of the six elements in the context of assessing pathways for a 1.5°C world.This article is part of the theme issue 'The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'.