scholarly journals Impact of idealized future stratospheric aerosol injection on the large-scale ocean and land carbon cycles

2016 ◽  
Vol 121 (1) ◽  
pp. 2-27 ◽  
Author(s):  
J. F. Tjiputra ◽  
A. Grini ◽  
H. Lee
Keyword(s):  
Large Scale ◽  
Stratospheric Aerosol ◽  
Carbon Cycles ◽  
Stratospheric Aerosol Injection

scholarly journals The Response of Permafrost and High‐Latitude Ecosystems Under Large‐Scale Stratospheric Aerosol Injection and Its Termination

2019 ◽  
Vol 7 (6) ◽  
pp. 605-614 ◽  
Author(s):  
Hanna Lee ◽  
Altug Ekici ◽  
Jerry Tjiputra ◽  
Helene Muri ◽  
Sarah E. Chadburn ◽  
...  
Keyword(s):  
High Latitude ◽  
Large Scale ◽  
Stratospheric Aerosol ◽  
Stratospheric Aerosol Injection

scholarly journals Updated and outdated reservations about research into stratospheric aerosol injection

2021 ◽  
Vol 164 (3-4) ◽  
Author(s):  
Wake Smith ◽  
Claire Henly
Keyword(s):  
Recent Literature ◽  
Early Stage ◽  
Stratospheric Aerosol ◽  
Research Community ◽  
Slippery Slope ◽  
Lock In ◽  
Stratospheric Aerosol Injection

AbstractIn this paper, we seek to ground discussions of the governance of stratospheric aerosol injection research in recent literature about the field including an updated understanding of the technology’s deployment logistics and scale, pattern of effects, and research pathways. Relying upon this literature, we evaluate several common reservations regarding the governance of pre-deployment research and testing including covert deployment, technological lock-in, weaponization, slippery slope, and the blurry line between research and deployment. We conclude that these reservations are no longer supported by literature. However, we do not argue that there is no reason for concern. Instead, we enumerate alternative bases for caution about research into stratospheric aerosol injection which are supported by an up-to-date understanding of the literature. We conclude that in order to establish the correct degree and type of governance for stratospheric aerosol injection research, the research community must focus its attention on these well-grounded reservations. However, while these reservations are supported and warrant further attention, we conclude that none currently justifies restrictive governance of early-stage stratospheric aerosol injection research.

scholarly journals Evaluation of modeled global carbon dynamics: analysis based on global carbon flux and above-ground biomass data

2016 ◽  
Author(s):  
Bao-Lin Xue ◽  
Qinghua Guo ◽  
Tianyu Hu ◽  
Yongcai Wang ◽  
Shengli Tao ◽  
...  
Keyword(s):  
Spatial Patterns ◽  
Carbon Flux ◽  
Large Scale ◽  
Gross Primary Production ◽  
Carbon Dynamics ◽  
Global Scale ◽  
Above Ground Biomass ◽  
Carbon Cycles ◽  
Ground Biomass ◽  
Global Carbon

Abstract. Dynamic global vegetation models are useful tools for the simulation of carbon dynamics on regional and global scales. However, even the most validated models are usually hampered by the poor availability of global biomass data in the model validation, especially on regional/global scales. Here, taking the integrated biosphere simulator model (IBIS) as an example, we evaluated the modeled carbon dynamics, including gross primary production (GPP) and potential above-ground biomass (AGB), on the global scale. The IBIS model was constrained by both in situ GPP and plot-level AGB data collected from the literature. Independent validation showed that IBIS could reproduce GPP and evapotranspiration with acceptable accuracy at site and global levels. On the global scale, the IBIS-simulated total AGB was similar to those obtained in other studies. However, discrepancies were observed between the model-derived and observed spatial patterns of AGB for Amazonian forests. The differences among the AGB spatial patterns were mainly caused by the single-parameter set of the model used. This study showed that different meteorological inputs can also introduce substantial differences in AGB on the global scale. Further analysis showed that this difference is small compared with parameter-induced differences. The conclusions of our research highlight the necessity of considering the heterogeneity of key model physiological parameters in modeling global AGB. The research also shows that to simulate large-scale carbon dynamics, both carbon flux and AGB data are necessary to constrain the model. The main conclusions of our research will help to improve model simulations of global carbon cycles.

scholarly journals Climate engineering and the ocean: effects on biogeochemistry and primary production

2017 ◽  
Author(s):  
Siv K. Lauvset ◽  
Jerry Tjiputra ◽  
Helene Muri
Keyword(s):  
Primary Production ◽  
Radiative Forcing ◽  
Large Scale ◽  
Stratospheric Aerosol ◽  
Climate Impacts ◽  
Environmental Drivers ◽  
Earth System ◽  
Climate Engineering ◽  
Mean Sea Surface ◽  
Radiation Management

Abstract. Here we use an Earth System Model with interactive biogeochemistry to project future ocean biogeochemistry impacts from large-scale deployment of three different radiation management (RM) climate engineering (also known as geoengineering) methods: stratospheric aerosol injection (SAI), marine sky brightening (MSB), and cirrus cloud thinning (CCT). We apply RM such that the change in radiative forcing in the RCP8.5 emission scenario is reduced to the change in radiative forcing in the RCP4.5 scenario. The resulting global mean sea surface temperatures in the RM experiments are comparable to those in RCP4.5, but there are regional differences. The forcing from MSB, for example, is applied over the oceans, so the cooling of the ocean is in some regions stronger for this method of RM than for the others. Changes in ocean primary production are much more variable, but SAI and MSB give a global decrease comparable to RCP4.5 (~ 6 % in 2100 relative to 1971–2000), while CCT give a much smaller global decrease of ~ 3 %. The spatially inhomogeneous changes in ocean primary production are partly linked to how the different RM methods affect the drivers of primary production (incoming radiation, temperature, availability of nutrients, and phytoplankton) in the model. The results of this work underscores the complexity of climate impacts on primary production, and highlights that changes are driven by an integrated effect of multiple environmental drivers, which all change in different ways. These results stress the uncertain changes to ocean productivity in the future and advocates caution at any deliberate attempt for large-scale perturbation of the Earth system.

scholarly journals Global streamflow and flood response to stratospheric aerosol geoengineering

2018 ◽  
Author(s):  
Liren Wei ◽  
Duoying Ji ◽  
Chiyuan Miao ◽  
John C. Moore
Keyword(s):  
Return Period ◽  
Flood Risk ◽  
Large Scale ◽  
Hydrological Cycle ◽  
Stratospheric Aerosol ◽  
Model Intercomparison ◽  
Geographic Pattern ◽  
Solar Geoengineering ◽  
Intercomparison Project ◽  
Future Warming

Abstract. Flood risk is projected to increase under projections of future warming climates due to an enhanced hydrological cycle. Solar geoengineering is known to reduce precipitation and slowdown the hydrological cycle, and may be therefore be expected to offset increased flood risk. We examine this hypothesis using streamflow and river discharge responses to the representative concentration pathway RCP4.5 and Geoengineering Model Intercomparison Project (GeoMIP) G4 experiments. We also calculate changes in 30, 50, 100-year flood return periods relative to the historical (1960–1999) period under the RCP4.5 and G4 scenarios. Similar spatial patterns are produced for each return period, although those under G4 are closer to historical values than under RCP4.5. Under G4 generally lower streamflows are produced on the western sides of Eurasia and North America, with higher flows on their eastern sides. In the southern hemisphere northern parts of the land masses have lower streamflow under G4, and southern parts increases relative to RCP4.5. So in general solar geoengineering does appear to reduce flood risk in most regions, but the relative effects are largely determined by this large scale geographic pattern. Both streamflow and return period show increased drying of the Amazon under both RCP4.5 and G4 scenarios, with more drying under G4.

scholarly journals Global streamflow and flood response to stratospheric aerosol geoengineering

2018 ◽  
Vol 18 (21) ◽  
pp. 16033-16050 ◽  
Author(s):  
Liren Wei ◽  
Duoying Ji ◽  
Chiyuan Miao ◽  
Helene Muri ◽  
John C. Moore
Keyword(s):  
Return Period ◽  
Flood Risk ◽  
Large Scale ◽  
Hydrological Cycle ◽  
Stratospheric Aerosol ◽  
Model Intercomparison ◽  
Geographic Pattern ◽  
Solar Geoengineering ◽  
Intercomparison Project ◽  
Future Warming

Abstract. Flood risk is projected to increase under future warming climates due to an enhanced hydrological cycle. Solar geoengineering is known to reduce precipitation and slow down the hydrological cycle and may therefore be expected to offset increased flood risk. We examine this hypothesis using streamflow and river discharge responses to Representative Concentration Pathway 4.5 (RCP4.5) and the Geoengineering Model Intercomparison Project (GeoMIP) G4 scenarios. Compared with RCP4.5, streamflow on the western sides of Eurasia and North America is increased under G4, while the eastern sides see a decrease. In the Southern Hemisphere, the northern parts of landmasses have lower streamflow under G4, and streamflow of southern parts increases relative to RCP4.5. We furthermore calculate changes in 30-, 50-, and 100-year flood return periods relative to the historical (1960–1999) period under the RCP4.5 and G4 scenarios. Similar spatial patterns are produced for each return period, although those under G4 are closer to historical values than under RCP4.5. Hence, in general, solar geoengineering does appear to reduce flood risk in most regions, but the overall effects are largely determined by this large-scale geographic pattern. Although G4 stratospheric aerosol geoengineering ameliorates the Amazon drying under RCP4.5, with a weak increase in soil moisture, the decreased runoff and streamflow leads to an increased flood return period under G4 compared with RCP4.5.

scholarly journals Greenland Ice Sheet Response to Stratospheric Aerosol Injection Geoengineering

2019 ◽  
Vol 7 (12) ◽  
pp. 1451-1463 ◽  
Author(s):  
John C. Moore ◽  
Chao Yue ◽  
Liyun Zhao ◽  
Xiaoran Guo ◽  
Shingo Watanabe ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Stratospheric Aerosol ◽  
Stratospheric Aerosol Injection

Emerging risk governance for stratospheric aerosol injection as a climate management technology

2019 ◽  
Vol 39 (4) ◽  
pp. 371-382 ◽  
Author(s):  
Khara D. Grieger ◽  
Tyler Felgenhauer ◽  
Ortwin Renn ◽  
Jonathan Wiener ◽  
Mark Borsuk
Keyword(s):  
Stratospheric Aerosol ◽  
Risk Governance ◽  
Management Technology ◽  
Emerging Risk ◽  
Climate Management ◽  
Stratospheric Aerosol Injection

scholarly journals Synthesis of Global Actual Evapotranspiration from 1982 to 2019

2020 ◽  
Author(s):  
Abdelrazek Elnashar ◽  
Linjiang Wang ◽  
Bingfang Wu ◽  
Weiwei Zhu ◽  
Hongwei Zeng
Keyword(s):  
Land Surface ◽  
Water Resource Management ◽  
Large Scale ◽  
The United States ◽  
Google Earth ◽  
Actual Evapotranspiration ◽  
Digital Object Identifier ◽  
Carbon Cycles ◽  
Study Results ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract. As a linkage among water, energy, and carbon cycles, global actual evapotranspiration (ET) plays an essential role in agriculture, water resource management, and climate change. Although it is difficult to estimate ET over a large scale and for a long time, there are several global ET datasets available with varied algorithms, parameters, and inputs, and they produce different levels of uncertainties. In this study, we propose a long-term synthesized ET product at a kilometer spatial resolution and monthly temporal resolution from 1982 to 2019. Through a site-pixel validation of certain global ET products over different land surface types and conditions, the high performing products were selected through a high-quality flux eddy covariance covering the entire globe. According to the study results, Penman-Monteith Leuning (PML), operational Simplified Surface Energy Balance (SSEBop), Moderate Resolution Imaging Spectroradiometer (MODIS, MOD16A2105) and the Numerical Terradynamic Simulation Group (NTSG) ET products were chosen to create the synthesized ET set. The proposed product agreed well with flux EC ET over most of the all comparison levels, with a maximum ME (RME) of 13.94 mm (17.13 %) and a maximum RMSE (RRMSE) of 38.61 mm (47.45 %). Furthermore, the product performed better than local ET products over China, the United States, and the African continent and presented an ET estimation across all land cover classes. While no product can perform best in all cases, the proposed ET can be used without looking at other datasets and performing further assessments. Data are available on the Harvard Dataverse public repository through the following Digital Object Identifier (DOI): https://doi.org/10.7910/DVN/ZGOUED (Elnashar et al., 2020) as well as it is available as Google Earth Engine (GEE) application through this link: https://elnashar.users.earthengine.app/view/synthesizedet.

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