Global streamflow and flood response to stratospheric aerosol geoengineering

Wei, Liren; Ji, Duoying; Miao, Chiyuan; Muri, Helene; Moore, John C.

doi:10.5194/acp-18-16033-2018

Cited by 20 publications

(17 citation statements)

References 112 publications

(170 reference statements)

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“…A sustained layer of additional sulfate aerosols in the stratosphere would scatter some of the incoming solar radiation back to space, cooling the Earth. Numerous climate modeling studies on SAG have suggested that it could reduce many impacts of anthropogenic global warming, such as sea level rise, floods, permafrost degradation, and extreme weather (e.g., Rasch et al, ; Moore et al, ; Irvine et al, ; Wei et al, ; Ji et al, ; Lee et al, ), and also have side effects such as decreased stratospheric ozone concentrations in polar regions (Pitari et al, ; Tilmes et al, ).…”

Section: Introductionmentioning

confidence: 99%

Stratospheric Sulfate Aerosol Geoengineering Could Alter the High‐Latitude Seasonal Cycle

Jiang

Cao

MacMartin

et al. 2019

Geophysical Research Letters

102

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Stratospheric aerosol geoengineering (SAG) has been proposed to reduce some impacts of anthropogenic climate change. Previous studies examined annual mean climate responses to SAG. Here we use the Stratospheric Aerosol Geoengineering Large Ensemble simulations to explore the effects of SAG on the seasonal cycle of climate change. Simulations show that relative to the present-day climate, SAG diminishes the amplitude of the seasonal cycle of temperature at many high-latitude locations, with warmer winters and cooler summers. The seasonal temperature shift significantly influences the seasonal cycle of snow depth and sea ice, with Arctic sea ice recovery overcompensated in summer by 52% and undercompensated in winter by 8%. We identify that both the dynamic effects of aerosol-induced stratospheric heating and seasonal variations of sunlight contribute to the shifts in seasonal cycle. Shifts in the seasonal cycle have important ecological and environmental implications, which should be considered in geoengineering impact analysis.Plain Language Summary Stratospheric aerosol geoengineering, by releasing sulfate aerosol particles or their precursors (SO 2 ) into the stratosphere to scatter more sunlight back to space, is a potential climate intervention option to counteract anthropogenic global warming. Previous studies focused on the effect of aerosol injection on annual mean climate change. Here we assess seasonal climate shifts in response to aerosol injection using a large ensemble of sophisticated climate model simulations. Relative to the high-CO 2 scenario, stratospheric aerosol injection can stabilize many aspects of climate change on the annual mean basis including global mean temperature, interhemispheric temperature gradient, and equator-to-pole temperature gradient. However, we find that injection of SO 2 into the stratosphere would substantially alter the high-latitude seasonal cycle. Relative to the present-day climate, in a high-CO 2 world with additional aerosols in the stratosphere, many high-latitude locations are warmer in winter and cooler in summer. Meanwhile, stratospheric aerosol geoengineering overcompensated Arctic sea ice extent recovery in summer and undercompensated it in winter. These seasonal climate shifts have important ecological, economic, and aesthetic implications for a full assessment of benefits and risks of stratospheric aerosol geoengineering. Key Points: • We use a large ensemble of simulations to explore high-latitude climate seasonal shifts under stratospheric aerosol geoengineering • Stratospheric aerosol geoengineering would alter seasonal cycle of temperature, snow depth, and sea ice at high latitudes • Stratospheric heating and seasonal sunlight variations are two likely mechanisms that cause shifts in high-latitude seasonal cycle Supporting Information: • Supporting Information S1

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Section: Introductionmentioning

confidence: 99%

Stratospheric Sulfate Aerosol Geoengineering Could Alter the High‐Latitude Seasonal Cycle

Jiang

Cao

MacMartin

et al. 2019

Geophysical Research Letters

102

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“…Such pattern resembles the present analysis of HadGEM2-ES. Wei et al (2018) analyzed the changes in global streamflow and flood return periods under the GeoMIP G4 scenario. Although it is not clear how the drought/flood pattern will respond over East Asia when geoengineering is employed, the aforementioned risk should be considered.…”

Section: Conclusion and Discussionmentioning

confidence: 99%

Impact of Stratospheric Aerosol Injection Geoengineering on the Summer Climate Over East Asia

Lang

Jiang

2021

JGR Atmospheres

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The United Nations Framework Convention on Climate Change (UNFCCC), which has been ratified by >190 countries worldwide, aims to limit global warming to <2°C above the preindustrial level. However, the fact that it is difficult to achieve the national CO 2 mitigation target encourages us to search for alternatives. The solar radiation modification (SRM) geoengineering, which is defined as a measure to temporarily reduce or offset global warming by changing the albedo of the Earth system and increasing the amount of solar radiation reflected from the Earth, has been proposed accordingly (Allen et al., 2018). As a kind of the SRM geoengineering, stratospheric aerosol injection (SAI) geoengineering can increase planetary albedo by injecting SO 2 into the stratosphere to form sulfate aerosols. A portion of incoming sunlight is therefore scattered and, in turn, leads to global cooling (Budyko, 1977;Crutzen, 2006;Wigley, 2006). This proposed technology is considered as one of the most promising SRM methods and thus widely studied in recent years (

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“…Simulations of global climate models show that the three RFGs have enough potential to lower the representative concentration pathway 8.5 (RCP8.5) global warming level to a warming level similar to that under RCP4.5 and even to a 1.5°C warming threshold (Kravitz et al, 2015;MacMartin et al, 2018). In contrast to their consistent cooling potentials, individual RFGs induce different impacts on the Earth's large-scale circulation, raising concerns over inequality risks of RFG impacts on regional climate and hydrological cycle (Crook et al, 2015;Irvine et al, 2010;Irvine et al, 2019;Wei et al, 2018), as well as the distribution and dynamics of climate regimes, such as drylands. Many assessments have examined the potential of RFGs to induce changes in the regional climate, especially precipitation (P) (Kristjánsson et al, 2015;Niemeier et al, 2013;Stjern et al, 2018), but the response of drylands to individual RFGs remains unexplored.…”

Section: Citationmentioning

confidence: 99%

Inequal Responses of Drylands to Radiative Forcing Geoengineering Methods

Park

Jeong

Fan

et al. 2019

Geophysical Research Letters

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Climate geoengineering has the potential to reduce global warming. However, the nonlinear responses of Earth's large-scale circulation to climate geoengineering can exacerbate regional climate change, with potential inequality risks. We show noticeable inequality in the responses of drylands when three radiative forcing geoengineering (RFG) methodologies-cirrus cloud thinning (CCT), marine sky brightening (MSB), and stratospheric aerosol injection (SAI)-individually reduce the radiative forcing of the representative concentration pathway 8.5 scenario using a set of the Norwegian Earth system model (NorESM1-ME) experiments. In North America, CCT and SAI alleviate drylands expansion, whereas drylands expand further under MSB. CCT induces significantly wetter conditions over the western Sahel. Wetting over Australia is enhanced and prevented by MSB and SAI, respectively. Our results suggest spatially inequal distributions of benefits and harms of individual RFGs on the projected distribution of drylands, which should be considered before any real-world application of such RFGs.Plain Language Summary Climate geoengineering has the potential to reduce global warming levels significantly, according to modeling experiments. However, regional impacts of individual climate geoengineering methods are inequal, raising concerns about fairness of negative side effects of such methods. Here, impacts of climate geoengineering on the global distribution of drylands are projected using an Earth system model, NorESM1-ME. Three geoengineering methods are adopted: cirrus cloud thinning (CCT), marine sky brightening (MSB), and stratospheric aerosol injection (SAI). All methods commonly reduce about 2°C of global warming in the late 21st century relative to the high CO 2 emission scenario, representative concentration pathway 8.5. Drylands respond differently to individual methods, especially in North America, the western Sahel, and Australia. In North America, CCT and SAI alleviate drylands expansion, whereas the expansion of drylands is intensified under MSB. CCT notably reduces drylands expansion over the western Sahel. The reduction of drylands in Australia is enhanced by MSB due to atmospheric circulation changes but prevented by SAI. Our results suggest that climate geoengineering can exacerbate drylands expansion in some regions despite potential alleviation in other regions. Such inequalities should be considered if RFGs for real-world applications to mitigate global warming were ever to be considered.

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Global streamflow and flood response to stratospheric aerosol geoengineering

Cited by 20 publications

References 112 publications

Stratospheric Sulfate Aerosol Geoengineering Could Alter the High‐Latitude Seasonal Cycle

Stratospheric Sulfate Aerosol Geoengineering Could Alter the High‐Latitude Seasonal Cycle

Impact of Stratospheric Aerosol Injection Geoengineering on the Summer Climate Over East Asia

Inequal Responses of Drylands to Radiative Forcing Geoengineering Methods

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