What if ‘negative emission technologies’ (NETs) fail at scale: Implications of the Paris Agreement for big emitting nations

This new paper is published in Climate Policy and is available at: http://www.tandfonline.com/doi/full/10.1080/14693062.2017.1346498 and http://dx.doi.org/10.1080/14693062.2017.1346498

A pre-edit version of the paper can be found at: ‘What if NETs fail at scale’ – pre-edit version of Climate Policy paper – August 2017

Authors: Alice Larkin, Jaise KuriakoseMaria Sharmina, and Kevin Anderson


A cumulative emissions approach is increasingly used to inform mitigation policy. However, there are different interpretations of what ‘2°C’ implies. Here it is argued that cost-optimisation models, commonly used to inform policy, typically underplay the urgency of 2°C mitigation. The alignment within many scenarios of optimistic assumptions on negative emissions technologies (NETs), with implausibly early peak emission dates and incremental short-term mitigation, delivers outcomes commensurate with 2°C commitments. In contrast, considering equity and socio-technical barriers to change, suggests a more challenging short-term agenda. To understand these different interpretations, short-term CO2 trends of the largest CO2 emitters, are assessed in relation to a constrained CO2 budget, coupled with a ‘what if’ assumption that negative emissions technologies fail at scale. The outcomes raise profound questions around high-level framings of mitigation policy. The paper concludes that applying even weak equity criteria, challenges the feasibility of maintaining a 50% chance of avoiding 2°C without urgent mitigation efforts in the short-term. This highlights a need for greater engagement with: (1) the equity dimension of the Paris Agreement, (2) the sensitivity of constrained carbon budgets to short-term trends and (3) the climate risks for society posed by an almost ubiquitous inclusion of NETs within 2°C scenarios.