Indicators and metrics for the assessment of climate engineering

Abstract

Selecting appropriate indicators is essential to aggregate the information provided by climate model outputs into a manageable set of relevant metrics on which assessments of climate engineering (CE) can be based. From all the variables potentially available from climate models, indicators need to be selected that are able to inform scientists and society on the development of the Earth system under CE, as well as on possible impacts and side effects of various ways of deploying CE or not. However, the indicators used so far have been largely identical to those used in climate change assessments and do not visibly reflect the fact that indicators for assessing CE (and thus the metrics composed of these indicators) may be different from those used to assess global warming. Until now, there has been little dedicated effort to identifying specific indicators and metrics for assessing CE. We here propose that such an effort should be facilitated by a more decision-oriented approach and an iterative procedure in close interaction between academia, decision makers, and stakeholders. Specifically, synergies and trade-offs between social objectives reflected by individual indicators, as well as decision-relevant uncertainties should be considered in the development of metrics, so that society can take informed decisions about climate policy measures under the impression of the options available, their likely effects and side effects, and the quality of the underlying knowledge base.

Quantifying and Comparing Effects of Climate Engineering Methods on the Earth System

“…Furthermore, as discussed above in the rankings of the CE methods, the choice of variables that are considered in the analysis plays a crucial role in the assessment of CE methods (Oschlies et al, ).…”

“…It is an open question which aspects of climate should be included in a comparative assessment of CE methods (Oschlies et al, ). Naturally, the focus is on surface air temperature, because the main aim of CE is to combat global warming and because changes in regional climate variables that local stakeholders and decision‐makers can relate to are correlated with changes in global mean surface air temperature (Seneviratne et al, ).…”

Reflecting upon 10 years of geoengineering research: Introduction to the Crutzen + 10 special issue

“…However, work on integrated, future-oriented assessment frameworks is underway. In this issue, [Boyd, 2016] outlines a set of geo-politically relevant geoengineering assessment criteria based on the potential transboundary effects of a range of techniques, and Oschlies et al [2016b] present a call for a decision-oriented approach to identify specific indicators and metrics for assessing geoengineering involving academia, decision-makers, and societal stakeholders. In their contribution, Irvine et al [2016b] detail moves toward integrating climate impacts into assessments of geoengineering.…”

Research for assessment, not deployment, of Climate Engineering: The German Research Foundation's Priority Program SPP 1689

“…Through such activities, the Priority Program aims to move from scientifically driven fundamental research toward answering policy-relevant research questions. Special research foci currently discussed by several projects of the Program are the investigation of trade offs between different CE schemes and mitigation and the necessary development of appropriate indicators and metrics as well as decision analysis frameworks (see article by Oschlies et al, 2016, in this special issue). Thanks to its interdisciplinary culture and its ambition for transparent research, the Priority Program is viewed as a promising tool to engage the scientific disciplines relevant for a comprehensive assessment of CE and to constructively engage in the discussion with stakeholders and policymakers.…”