A Scheme for Jointly Trading off Costs and Risks of Solar Radiation Management and Mitigation Under Long-Tailed Climate Sensitivity Probability Density Distributions

AbstractSide effects of “solar-radiation management” (SRM) might be perceived as an important metric when society decides on implementing SRM as a climate policy option to alleviate anthropogenic global warming. We generalize cost-risk analysis that originally trades off expected welfare loss from climate policy costs and risks from transgressing climate targets to also include risks from applying SRM. In a first step of acknowledging SRM risks, we represent global precipitation mismatch as a prominent side effect of SRM under long-tailed probabilistic knowledge about climate sensitivity. We maximize a social welfare function for the following three scenarios, considering alternative relative weights of risks: temperature-risk-only, precipitation-risk-only, and equally-weighted both-risks. Our analysis shows that in the temperature-risk-only scenario, perfect compliance with the 2 °C-temperature target is attained for all numerically represented climate sensitivities, a unique feature of SRM, but the 2 °C-compatible precipitation corridor is violated. The precipitation-risk-only scenario exhibits an approximate mirror-image of this result. In addition, under the both-risks scenario, almost 90% and perfect compliance can be achieved for the temperature and precipitation targets, respectively. Moreover, in a mitigation-only analysis, the welfare loss from mitigation cost plus residual climate risks, compared to the no-climate-policy option, is approximately 4.3% (in terms of balanced growth equivalent), while being reduced more than 90% under a joint-mitigation-SRM analysis.

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Complementing CO2 emission reduction by solar radiation management might strongly enhance future welfare

Earth System Dynamics ◽

10.5194/esd-10-453-2019 ◽

2019 ◽

Vol 10 (3) ◽

pp. 453-472 ◽

Cited By ~ 2

Author(s):

Koen G. Helwegen ◽

Claudia E. Wieners ◽

Jason E. Frank ◽

Henk A. Dijkstra

Keyword(s):

Global Warming ◽

Solar Radiation ◽

Cost Benefit Analysis ◽

Cost Benefit ◽

Policy Option ◽

Integrated Assessment Model ◽

Assessment Model ◽

Solar Radiation Management ◽

Stochastic Dynamic ◽

Radiation Management

Abstract. Solar radiation management (SRM) has been proposed as a means to reduce global warming in spite of high greenhouse-gas concentrations and to lower the chance of warming-induced tipping points. However, SRM may cause economic damages and its feasibility is still uncertain. To investigate the trade-off between these (economic) gains and damages, we incorporate SRM into a stochastic dynamic integrated assessment model and perform the first rigorous cost–benefit analysis of sulfate-based SRM under uncertainty, treating warming-induced climate tipping and SRM failure as stochastic elements. We find that within our model, SRM has the potential to greatly enhance future welfare and merits being taken seriously as a policy option. However, if only SRM and no CO2 abatement is used, global warming is not stabilised and will exceed 2 K. Therefore, even if successful, SRM can not replace but only complement CO2 abatement. The optimal policy combines CO2 abatement and modest SRM and succeeds in keeping global warming below 2 K.

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Counteracting global warming by using a locally variable Solar Radiation Management

10.5194/egusphere-egu2020-12307 ◽

2020 ◽

Author(s):

Davide Marchegiani ◽

Dietmar Dommenget

Keyword(s):

Global Warming ◽

Solar Radiation ◽

Cloud Cover ◽

Global Climate ◽

Solar Radiation Management ◽

Intergovernmental Panel ◽

Global Average ◽

Temperature And Precipitation ◽

Precipitation Response ◽

Radiation Management

Solar Radiation Management (SRM) is regarded as a tool which could potentially mitigate or completely offset global warming by increasing planetary albedo. However, this approach could potentially reduce precipitation as well, as shown in the latest Intergovernmental Panel on Climate Change (ICPP) 5th report. Thus, although SRM might weaken global climate risks, it may enhance those in some regions. Here, using the Globally Resolved Energy Balance (GREB) model, we present experiments designed to completely offset the temperature and precipitation response due to a&#160;CO2-doubling experiment (abrupt2&#215;CO2). The main idea around which our study is built upon is to employ a localized and seasonally varying SRM, as opposed to the most recent Geo-Engineering experiments which just apply a global and homogeneous one. In order to achieve such condition, we carry out the computation by using an &#8220;artificial cloud cover&#8221;. The usage of this localized approach allows us to globally cut down temperature warming in the abrupt2&#215;CO2 scenario by 99.8% (which corresponds to an increase of 0.07 &#176;C on a global average basis), while at the same time only having minor changes in precipitation (0.003 mm/day on a global average basis). To achieve this the cloud cover is increased by about 8% on a global average. Moreover, neither temperature nor precipitation response are exacerbated when averaged over any IPCC Special Report on Extremes (SREX) region. Indeed, for temperatures, 90% of SREX regions averages fall within 0.3 &#176;C change, with all regional mean anomalies being under 0.38 &#176;C. Whereas, as far as precipitation is concerned, changes go up to 0.01 mm/day for 90% of SREX regions, with all of them changing by less than 0.02 mm/day. Similar results are achieved for seasonal variations, with Seasonal Cycle (DJF-JJA) having no major changes in both surface temperature and precipitation.

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Estimating option values of solar radiation management assuming that climate sensitivity is uncertain

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1520795113 ◽

2016 ◽

Vol 113 (21) ◽

pp. 5886-5891 ◽

Cited By ~ 9

Author(s):

Yosuke Arino ◽

Keigo Akimoto ◽

Fuminori Sano ◽

Takashi Homma ◽

Junichiro Oda ◽

...

Keyword(s):

Side Effects ◽

Solar Radiation ◽

Climate Sensitivity ◽

Maximum Level ◽

Integrated Assessment Model ◽

Assessment Model ◽

Solar Radiation Management ◽

Option Value ◽

Option Values ◽

Radiation Management

Although solar radiation management (SRM) might play a role as an emergency geoengineering measure, its potential risks remain uncertain, and hence there are ethical and governance issues in the face of SRM’s actual deployment. By using an integrated assessment model, we first present one possible methodology for evaluating the value arising from retaining an SRM option given the uncertainty of climate sensitivity, and also examine sensitivities of the option value to SRM’s side effects (damages). Reflecting the governance challenges on immediate SRM deployment, we assume scenarios in which SRM could only be deployed with a limited degree of cooling (0.5 °C) only after 2050, when climate sensitivity uncertainty is assumed to be resolved and only when the sensitivity is found to be high (T2x = 4 °C). We conduct a cost-effectiveness analysis with constraining temperature rise as the objective. The SRM option value is originated from its rapid cooling capability that would alleviate the mitigation requirement under climate sensitivity uncertainty and thereby reduce mitigation costs. According to our estimates, the option value during 1990–2049 for a +2.4 °C target (the lowest temperature target level for which there were feasible solutions in this model study) relative to preindustrial levels were in the range between $2.5 and $5.9 trillion, taking into account the maximum level of side effects shown in the existing literature. The result indicates that lower limits of the option values for temperature targets below +2.4 °C would be greater than $2.5 trillion.

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Effectiveness of stratospheric solar-radiation management as a function of climate sensitivity

Nature Climate Change ◽

10.1038/nclimate1328 ◽

2011 ◽

Vol 2 (2) ◽

pp. 92-96 ◽

Cited By ~ 16

Author(s):

Katharine L. Ricke ◽

Daniel J. Rowlands ◽

William J. Ingram ◽

David W. Keith ◽

M. Granger Morgan

Keyword(s):

Solar Radiation ◽

Climate Sensitivity ◽

Solar Radiation Management ◽

Radiation Management

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How can solar geoengineering and mitigation be combined under climate targets?

Earth System Dynamics ◽

10.5194/esd-12-1529-2021 ◽

2021 ◽

Vol 12 (4) ◽

pp. 1529-1542

Author(s):

Mohammad M. Khabbazan ◽

Marius Stankoweit ◽

Elnaz Roshan ◽

Hauke Schmidt ◽

Hermann Held

Keyword(s):

Side Effects ◽

Climate Policy ◽

Policy Option ◽

Solar Radiation Management ◽

Policy Tool ◽

Trade Offs ◽

Negative Emissions ◽

Solar Geoengineering ◽

Radiation Management

Abstract. So far, scientific analyses have mainly focused on the pros and cons of solar geoengineering or solar radiation management (SRM) as a climate policy option in mere isolation. Here, we put SRM into the context of mitigation by a strictly temperature-target-based approach. As the main innovation, we present a scheme that extends the applicability regime of temperature targets from mitigation-only to SRM-mitigation analyses. We explicitly account for one major category of side effects of SRM while minimizing economic costs for complying with the 2 ∘C temperature target. To do so, we suggest regional precipitation guardrails that are compatible with the 2 ∘C target. Our analysis shows that the value system enshrined in the 2 ∘C target leads to an elimination of most of the SRM from the policy scenario if a transgression of environmental targets is confined to 1/10 of the standard deviation of natural variability. Correspondingly, about half to nearly two-thirds of mitigation costs could be saved, depending on the relaxation of the precipitation criterion. In addition, assuming a climate sensitivity of 3 ∘C or more, in case of a delayed enough policy, a modest admixture of SRM to the policy portfolio might provide debatable trade-offs compared to a mitigation-only future. Also, in our analysis which abstains from a utilization of negative emissions technologies, for climate sensitivities higher than 4 ∘C, SRM will be an unavoidable policy tool to comply with the temperature targets. The economic numbers we present must be interpreted as upper bounds in the sense that cost-lowering effects by including negative emissions technologies are absent. However, with an additional climate policy option such as carbon dioxide removal present, the role of SRM would be even more limited. Hence, our results, pointing to a limited role of SRM in a situation of immediate implementation of a climate policy, are robust in that regard. This limitation would be enhanced if further side effects of SRM are taken into account in a target-based integrated assessment of SRM.

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