Abstract. Solar climate intervention using stratospheric aerosol injection
is a proposed method of reducing global mean temperatures to reduce the
worst consequences of climate change. A detailed assessment of responses and
impacts of such an intervention is needed with multiple global models to
support societal decisions regarding the use of these approaches to help
address climate change. We present a new modeling protocol aimed at
simulating a plausible deployment of stratospheric aerosol injection and
reproducibility of simulations using other Earth system models: Assessing
Responses and Impacts of Solar climate intervention on the Earth system with
stratospheric aerosol injection (ARISE-SAI). The protocol and simulations
are aimed at enabling community assessment of responses of the Earth system
to solar climate intervention. ARISE-SAI simulations are designed to be more
policy-relevant than existing large ensembles or multi-model simulation
sets. We describe in detail the first set of ARISE-SAI simulations,
ARISE-SAI-1.5, which utilize a moderate emissions scenario, introduce
stratospheric aerosol injection at ∼21.5 km in the year 2035, and
keep global mean surface air temperature near 1.5 ∘C above the
pre-industrial value utilizing a feedback or control algorithm. We present
the detailed setup, aerosol injection strategy, and preliminary
climate analysis from a 10-member ensemble of these simulations carried out
with the Community Earth System Model version 2 with the Whole Atmosphere
Community Climate Model version 6 as its atmospheric component.


/pdf/assessing-responses-and-impacts-of-solar-climate-18f6n3rl.pdf

Assessing Responses and Impacts of Solar climate intervention on the Earth system with stratospheric aerosol injection (ARISE-SAI): protocol and initial results from the first simulations

High‐Latitude Stratospheric Aerosol Injection to Preserve the Arctic

Abstract. Extreme weather events have been demonstrated to be increasing in frequency
and intensity across the globe and are anticipated to increase further with
projected changes in climate. Solar climate intervention strategies,
specifically stratospheric aerosol injection (SAI), have the potential to
minimize some of the impacts of a changing climate while more robust
reductions in greenhouse gas emissions take effect. However, to date little
attention has been paid to the possible responses of extreme weather and
climate events under climate intervention scenarios. We present an analysis
of 16 extreme surface temperature and precipitation indices, as well as associated
vegetation responses, applied to the Geoengineering Large Ensemble (GLENS).
GLENS is an ensemble of simulations performed with the Community Earth
System Model (CESM1) wherein SAI is simulated to offset the warming produced
by a high-emission scenario throughout the 21st century, maintaining surface
temperatures at 2020 levels. GLENS is generally successful at maintaining global mean temperature near
2020 levels; however, it does not completely offset some of the projected
warming in northern latitudes. Some regions are also projected to cool
substantially in comparison to the present day, with the greatest decreases
in daytime temperatures. The differential warming–cooling also translates to
fewer very hot days but more very hot nights during the summer and fewer
very cold days or nights compared to the current day. Extreme precipitation
patterns, for the most part, are projected to reduce in intensity in areas
that are wet in the current climate and increase in intensity in dry areas.
We also find that the distribution of daily precipitation becomes more
consistent with more days with light rain and fewer very intense events
than currently occur. In many regions there is a reduction in the
persistence of long dry and wet spells compared to present day. However,
asymmetry in the night and day temperatures, together with changes in cloud
cover and vegetative responses, could exacerbate drying in regions that are
already sensitive to drought. Overall, our results suggest that while SAI
may ameliorate some of the extreme weather hazards produced by global
warming, it would also present some significant differences in the
distribution of climate extremes compared to the present day.


/pdf/indices-of-extremes-geographic-patterns-of-change-in-2ar3jcq9.pdf

Indices of extremes: geographic patterns of change in extremes and associated vegetation impacts under climate intervention

The impacts of Stratospheric Aerosol Injection (SAI) strategies on the Southern Annular Mode (SAM) are analyzed with the Community Earth System Model. Using a set of simulations with fixed single-point SO2 injections we demonstrate the first-order dependence of the SAM response on the latitude of injection, with the northern hemispheric and equatorial injections driving a response corresponding to a positive phase of SAM and the southern hemispheric injections driving a negative phase of SAM. We further demonstrate that the results can to first order explain the differences in the SAM responses diagnosed from the two recent large ensembles of geoengineering simulations utilizing more complex injection strategies – Geoengineering Large Ensemble and Assessing Responses and Impacts of Solar climate intervention on the Earth system with Stratospheric Aerosol Injection (GLENS and ARISE-SAI) – as driven by the differences in the simulated sulfate aerosol distributions. Our results point to the meridional extent of aerosol-induced lower stratospheric heating as an important driver of the sensitivity of the SAM response to the injection location. 

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2022GL100353

Impact of the Latitude of Stratospheric Aerosol Injection on the Southern Annular Mode

Abstract Stratospheric aerosol injection (SAI) of reflective sulfate aerosols has been proposed to temporarily reduce the impacts of global warming. In this study, we compare two SAI simulations which inject at different altitudes to provide the same amount of cooling, finding that lower‐altitude SAI requires 64% more injection. SAI at higher altitudes cools the surface more efficiently per unit injection than lower‐altitude SAI through two primary mechanisms: the longer lifetimes of SO 2 and SO 4 at higher altitudes, and the water vapor feedback, in which lower‐altitude SAI causes more heating in the tropical cold point tropopause region, thereby increasing water vapor transport into the stratosphere and trapping more terrestrial infrared radiation that offsets some of the direct aerosol‐induced cooling. We isolate these individual mechanisms and find that the contribution of lifetime effects to differences in cooling efficiency is approximately five to six times larger than the contribution of the water vapor feedback. 

Quantifying the Efficiency of Stratospheric Aerosol Geoengineering at Different Altitudes

Abstract. Solar climate intervention using stratospheric aerosol injection is a proposed method of reducing global mean temperatures to reduce some of the consequences of climate change. A detailed assessment of responses and impacts of such an intervention is needed with multiple global models to support societal decisions regarding the use of these approaches to help address climate change. We present here a new modeling protocol and a 10-member ensemble of simulations using one of the most comprehensive Earth system models, aimed at simulating a plausible deployment of stratospheric aerosol injection and reproducibility of simulations using other Earth system models to enable community assessment of responses of the Earth system to solar climate intervention. The Assessing Responses and Impacts of Solar climate intervention on the Earth system with stratospheric aerosol injection (ARISE-SAI) simulations utilize a moderate emission scenario, introduce stratospheric aerosol injection at ~ 21 km in year 2035, and keep global mean surface air temperature near 1.5 °C above the pre-industrial value (ARISE-SAI-1.5). We present here the detailed set-up, aerosol injection strategy, and mean surface climate changes in these simulations so they can be reproduced in other global models. 

Assessing Responses and Impacts of Solar climate intervention on the Earth system with stratospheric aerosol injection (ARISE-SAI)

Abstract. There is now a substantial literature of climate model studies of equatorial or tropical stratospheric SO2 injections that aim to counteract the surface warming produced by rising concentrations of greenhouse gases. Here we present the results from the first systematic intercomparison of climate responses in three Earth System Models where the injection of SO2 occours at different latitudes in the lower stratosphere. Our aim is to determine commonalities and differences between the climate model responses in terms of the distribution of the optically reflective sulfate aerosols produced from the oxidation of SO2, and in terms of the surface response to the resulting reduction in solar radiation. A focus on understanding the contribution of characteristics of models transport alongside their microphysical and chemical schemes, and on evaluating the resulting stratospheric responses in different models is given in the companion paper (Bednarz et al., 2022). The goal of this exercise is not to evaluate these single point injection simulations as stand-alone proposed strategies to counteract global warming; instead we determine sources and areas of agreement and uncertainty in the simulated responses and, ultimately, the possibility of designing a comprehensive intervention strategy capable of managing multiple simultaneous climate goals through the combination of different injection locations. We find large disagreements between GISS-E2.1-G and the CESM2-WACCM6 and UKESM1.0 models regarding the magnitude of cooling per unit of aerosol optical depth (AOD) produced, from 4.7 K per unit of AOD in CESM2-WACCM6 to 16.7 K in the GISS-E2.1-G version with modal aerosol microphysics. By normalizing the results with the global mean response in each of the models, and thus assuming that the amount of SO2 injected is a free parameter that can be managed independently, we highlight some commonalities in the overall distributions of the aerosols, in the inter-hemispheric surface temperature response and in shifts to the Inter-Tropical Convergence Zone, and also some areas of disagreement, such as the aerosol confinement in the equatorial region and the transport to polar latitudes. 

Climate response to off-equatorial stratospheric sulfur injections in three Earth System Models – Part 1: experimental protocols and surface changes

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Wanghua Chen

Author Tools

Chat about Author

Papers

Assessing Responses and Impacts of Solar climate intervention on the Earth system with stratospheric aerosol injection (ARISE-SAI)

Climate response to off-equatorial stratospheric sulfur injections in three Earth System Models – Part 1: experimental protocols and surface changes