Quantifying the potential scale of mitigation deterrence from greenhouse gas removal techniques
- PDF / 809,232 Bytes
- 18 Pages / 439.37 x 666.142 pts Page_size
- 100 Downloads / 156 Views
Quantifying the potential scale of mitigation deterrence from greenhouse gas removal techniques Duncan McLaren 1 Received: 4 April 2019 / Accepted: 27 April 2020/ # The Author(s) 2020
Abstract
Greenhouse gas removal (GGR) techniques appear to offer hopes of balancing limited global carbon budgets by removing substantial amounts of greenhouse gases from the atmosphere later this century. This hope rests on an assumption that GGR will largely supplement emissions reduction. The paper reviews the expectations of GGR implied by integrated assessment modelling, categorizes ways in which delivery or promises of GGR might instead deter or delay emissions reduction, and offers a preliminary estimate of the possible extent of three such forms of ‘mitigation deterrence’. Type 1 is described as ‘substitution and failure’: an estimated 50–229 Gt-C (or 70% of expected GGR) may substitute for emissions otherwise reduced, yet may not be delivered (as a result of political, economic or technical shortcomings, or subsequent leakage or diversion of captured carbon into short-term utilization). Type 2, described as ‘rebounds’, encompasses rebounds, multipliers, and side-effects, such as those arising from land-use change, or use of captured CO2 in enhanced oil recovery. A partial estimate suggests that this could add 25–134 Gt-C to unabated emissions. Type 3, described as ‘imagined offsets’, is estimated to affect 17–27% of the emissions reductions required, reducing abatement by a further 182–297 Gt-C. The combined effect of these unanticipated net additions of CO2 to the atmosphere is equivalent to an additional temperature rise of up to 1.4 °C. The paper concludes that such a risk merits further deeper analysis and serious consideration of measures which might limit the occurrence and extent of mitigation deterrence. Keywords Greenhouse gas removal . Mitigation deterrence . Climate policy . Climate modelling
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10584-02002732-3) contains supplementary material, which is available to authorized users.
* Duncan McLaren [email protected]
1
Lancaster Environment Centre, Lancaster University, Lancaster, UK
Climatic Change
1 Introduction In the context of aspirations to limit the average global temperature rise, techniques which can draw greenhouse gases (GHG) from the air have become increasingly significant to climate policy. Integrated assessment models (IAMs) suggest that very substantial use of such techniques (variously termed carbon dioxide removal, negative emissions techniques, or greenhouse gas removal (GGR)) is likely necessary to stabilize atmospheric GHG concentrations at levels compatible with limiting average global temperature rises to 2 °C or lower (Fuss et al. 2014, Wiltshire and Davies-Barnard 2015, Minx et al. 2018). In modelled climate pathways that meet such goals, GGR is typically deployed later in the century (notably in the form of bioenergy with carbon capture and storage (BECCS)), alongside accelerated
Data Loading...
