Safe vs. Fair: A Formidable Trade-off in Tackling Climate Change

Abstract

Global warming requires a response characterized by forward-looking management of atmospheric carbon and respect for ethical principles. Both safety and fairness must be pursued, and there are severe trade-offs as these are intertwined by the limited headroom for additional atmospheric CO 2 emissions. This paper provides a simple numerical mapping at the aggregated level of developed vs. developing countries in which safety and fairness are formulated in terms of cumulative emissions and cumulative per capita emissions respectively. It becomes evident that safety and fairness cannot be achieved simultaneously for strict definitions of both. The paper further posits potential global trading in future cumulative emissions budgets in a world where financial transactions compensate for physical emissions: the safe vs. fair tradeoff is less severe but remains formidable. Finally, we explore very large deployment of engineered carbon sinks and show that roughly 1,000 Gt CO 2 of cumulative negative emissions over the century are required to have a significant effect, a remarkable scale of deployment. We also identify the unexplored issue of how such sinks might be treated in sub-global carbon accounting.

Climate justice and the international regime: before, during, and after Paris

“…While general principles of differentiation have nominal weight, the complexity of realizing justice means that with no framework there is little prospect that voluntary global climate action will be structured in a manner consistent with principles of fairness and justice. The inability of the international regime to impose or encourage the application of one or a limited set of justice principles remains a perennial constraint on the regime's effectiveness and a challenge when translating justice concerns into practical action . Meanwhile, in the midst of the cacophony of perspectives, emissions are increasing as are negative impacts on vulnerable communities around the world.…”

Post-2020 climate agreements in the major economies assessed in the light of global models

“…However, when the carbon budget is tight, as it is the case in 2°C policies, even resource sharing schemes such as those based on per capita equalization would not compensate for the inequality in favor of OECD countries 14,78 . A particular challenge lies in the uncertainty about the relations between regional emission allocation and costs, which is much greater than the uncertainty in global mitigation costs.…”

Direct air capture of CO2 and climate stabilization: A model based assessment

“…When accounting for the additional trade-off between climate safety and fairness, carbon removal programs of massive scale (e.g. 1000 GtCO 2 ) have been proposed (Tavoni et al 2012). Already, century-scale integrated assessment models (IAMs) foresee a significant role of negative emissions (Azar et al 2010), as these would allow to reach otherwise infeasible targets ) and to implement more modest emission reductions in the short and medium term .…”