Schlagwort: climate modelling

Nature – Schwinger et al. (2022): Possibility for strong northern hemisphere high-latitude cooling under negative emissions

Jörg Schwinger, Ali Asaadi, Nadine Goris, Hanna Lee IN: Nature Communications 13, 1095, https://doi.org/10.1038/s41467-022-28573-5

It is well established that a collapse or strong reduction of the Atlantic meridional overturning circulation (AMOC) would substantially cool the northern high latitudes. Here the authors show that there is a possibility that such cooling could be amplified under deliberate CO2 removal and result in a temporary undershoot of a targeted temperature level.

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Quaglia, Ilaria; et al. (2021): A novel approach to sulfate geoengineering with surface emissions of carbonyl sulfide

Quaglia, Ilaria; Visioni, Daniele; Pitari, Giovanni; Kravitz, Ben (2021): A novel approach to sulfate geoengineering with surface emissions of carbonyl sulfide. (Preprint). In Atmos. Chem. Phys. Discuss. DOI: 10.5194/acp-2021-813.

„Sulfate geoengineering (SG) methods based on lower stratospheric tropical injection of sulfur dioxide (SO2) have been widely discussed in recent years, focusing on the direct and indirect effects they would have on the climate system. Here a potential alternative method is discussed, where sulfur emissions are located at the surface in the form of carbonyl sulfide (COS) gas. A time-dependent chemistry-climate model experiment is designed from year 2021 to 2055, assuming a 40 Tg-S/yr artificial global flux of COS, geographically distributed following the present day anthropogenic COS surface emissions. The budget of COS and sulfur species is discussed, as well as the effects of SG-COS on the stratospheric sulfate aerosol optical depth (Δ τ = 0.080 in years 2046–2055), aerosol effective radius (0.46 μm), surface SOx deposition (+8.7 %) and tropopause radiative forcing (RF) (−2.0 W/m2 for clear sky conditions and −1.5 W/m2 including the cloud adjustment). Indirect effects on ozone, methane and stratospheric water vapor are also considered, along with the COS direct contribution (with an overall gas phase global radiative forcing of +0.23 W/m2). According to our model results, the resulting net RF of this SG-COS experiment is −1.3 W/m2 for the year 2050, and it is comparable to the corresponding RF of −1.7 W/m2 obtained with a sustained injection of 4 Tg-S/yr in the tropical lower stratosphere in the form of SO2 (SG-SO2, able to produce a comparable increase of the sulfate aerosol optical depth). Significant changes of the stratospheric ozone response are found in SG-COS with respect to SG-SO2 (+4.9 DU versus +1.5 DU, globally). According to the model results, the resulting UVB perturbation at the surface accounts to −4.3 % as a global-annual average (versus −2.4 % in the SG-SO2 case), with a springtime Antarctic decrease of −2.7 % (versus a +5.8 % increase in the SG-SO2 experiment). Overall, we find that an increase in COS surface emission may be feasible, and produce a more latitudinally-uniform forcing without the need for the deployment of stratospheric aircrafts.“

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Call for Papers: MDPI Special Issue „Advances in Carbon Dioxide Removal Technologies“

Deadline: 10. April 2022

„Recent estimates show that global carbon dioxide emissions were more than 33 gigatons in 2018, following which several international agreements were signed in order to reduce greenhouse gases in the atmosphere. However, in order to achieve these fixed objectives, the conventional mitigation actions, meaning the reduction of carbon dioxide emissions, might be not enough and the removal of carbon dioxide might be required. Negative emission technologies based on carbon dioxide removal will play a crucial role in the coming years to achieve the defined environmental agreements and stabilize the carbon dioxide concentration between 350 and 440 ppmv. This Special Issue, entitled Carbon Dioxide Removal Technologies in the Applied Sciences journal, addresses the important role of these new systems to reach the set environmental targets. The issue covers original reviews, experimental and modelling research, and case studies related to carbon dioxide removal technologies. All aspects related to new developments and challenges in this research area will be included.“

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Goode, P. R.; et al. (2021): Earth’s Albedo 1998–2017 as Measured From Earthshine

Goode, P. R.; Pallé, E.; Shoumko, A.; Shoumko, S.; Montañes‐Rodriguez, P.; Koonin, S. E. (2021): Earth’s Albedo 1998–2017 as Measured From Earthshine. In Geophysical Research Letters 48 (17). DOI: 10.1029/2021GL094888.

„The reflectance of the Earth is a fundamental climate parameter that we measured from Big Bear Solar Observatory between 1998 and 2017 by observing the earthshine using modern photometric techniques to precisely determine daily, monthly, seasonal, yearly and decadal changes in terrestrial albedo from earthshine. We find the inter-annual fluctuations in albedo to be global, while the large variations in albedo within individual nights and seasonal wanderings tend to average out over each year. We measure a gradual, but climatologically significant urn:x-wiley:00948276:media:grl62955:grl62955-math-00010.5 W/m2 decline in the global albedo over the two decades of data. We found no correlation between the changes in the terrestrial albedo and measures of solar activity. The inter-annual pattern of earthshine fluctuations are in good agreement with those measured by CERES (data began in 2001) even though the satellite observations are sensitive to retroflected light while earthshine is sensitive to wide-angle reflectivity. The CERES decline is about twice that of earthshine.“

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Call for Abstracts: 2nd International Conference on Negative CO2 Emissions

Deadline: 1. December 2021

„The objective of the Paris Agreement is to limit global warming to well below 2ºC, and to pursue efforts to limit the temperature increase to 1.5ºC. The carbon budget is the amount of carbon dioxide that we can emit while still limiting global temperature rise to a given level, for example 1.5ºC.The exact size of the carbon budget is uncertain and depends on many factors, including potential future warming of non-CO2 climate forcers. This said, the remaining budgets for limiting the warming to 1.5ºC or 2ºC have been estimated at about 420 and 1170 Gt of CO2 . With unchanged present emissions at about 40 Gt CO2/year these budgets would be exhausted in as few as 10 and 30 years, respectively. Most of the IPCC emission scenarios that meet a global two-degree target in 2100 overshoot the carbon budget at first and then remove the excess carbon with large negative emissions, typically on the order of 400‑800 Gt CO2 up to 2100.At the same time as negative emissions appear to be indispensable to meet adopted climate targets, the large future negative emissions assumed in climate models have been questioned and warnings have been raised about relying on very large and uncertain negative emissions in the future. With the future climate at stake, a deeper and fuller understanding of the various aspects of negative emissions is needed.“

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Kuswanto, Heri; et al. (2021): Impact of Solar Geoengineering on Temperatures over the Indonesian Maritime Continent

Kuswanto, Heri; Kravitz, Ben; Miftahurrohmah, Brina; Fauzi, Fatkhurokhman; Sopahaluwaken, Ardhasena; Moore, John (2021): Impact of Solar Geoengineering on Temperatures over the Indonesian Maritime Continent. In Int J Climatol. DOI: 10.1002/joc.7391.

„Climate change has been projected to increase the intensity and magnitude of extreme temperature in Indonesia. Solar radiation management (SRM) has been proposed as a strategy to temporarily combat global warming, buying time for negative emissions. Though the global impacts of SRM have been extensively studied in recent years, regional impacts, especially in the tropics, have received much less attention. This paper investigates the potential stratospheric sulfate aerosol injection (SAI) to modify mean and extreme temperature, as well as the relative humidity and wet bulb temperature (WBT) change over Indonesian Maritime Continent (IMC) based on simulations from three different earth system models. We applied a simple downscaling method and corrected the bias of model output to reproduce historical temperatures and relative humidity over IMC. We evaluated changes in Geoengineering Model Intercomparison Project (GeoMIP) experiment G4, an SAI experiment in 5 Tg of SO2 into the equatorial lower stratosphere between 2020 and 2069, concurrent with the RCP4.5 emissions scenario.“

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Zickfeld, Kirsten; et al. (2021): Asymmetry in the climate–carbon cycle response to positive and negative CO2 emissions

Zickfeld, Kirsten; Azevedo, Deven; Mathesius, Sabine; Matthews, H. Damon (2021): Asymmetry in the climate–carbon cycle response to positive and negative CO2 emissions. In Nat. Clim. Chang., pp. 1–5. DOI: 10.1038/s41558-021-01061-2.

“ It is commonly assumed that the climate–carbon cycle response to a negative CO2 emission is equal in magnitude and opposite in sign to the response to an equivalent positive CO2 emission. Here we test the hypothesis that this response is symmetric by forcing an Earth system model with positive and negative CO2 emission pulses of varying magnitude and applied from different climate states.“

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Saidi, Majid; Inaloo, Ebrahim Balaghi (2021): CO2 Removal Using 1DMA2P Solvent via Membrane Technology: Rate Based Modeling and Sensitivity Analysis

Saidi, Majid; Inaloo, Ebrahim Balaghi (2021): CO2 Removal Using 1DMA2P Solvent via Membrane Technology: Rate Based Modeling and Sensitivity Analysis. In Chemical Engineering and Processing – Process Intensification, p. 108464. DOI: 10.1016/j.cep.2021.108464.

„A numerically solved reaction rate/kinetic model for CO2 removal from a CO2/N2 gas mixture into novel reactive 1-dimethylamino-2-propanol (1DMA2P) solution in a gas–liquid membrane contactor was constructed.“

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Belmonte, Beatriz A.; et al. (2021): A fuzzy optimization model for planning integrated terrestrial carbon management networks

Belmonte, Beatriz A.; Aviso, Kathleen B.; Benjamin, Michael Francis D.; Tan, Raymond R. (2021): A fuzzy optimization model for planning integrated terrestrial carbon management networks. In Clean Techn Environ Policy, pp. 1–13. DOI: 10.1007/s10098-021-02119-7.

„Although recent papers have reported the development of process integration models for optimizing carbon management networks based on either biochar application or enhanced weathering, none have reported models integrating these two NETs in the same system. To address this gap, a fuzzy mixed-integer linear programming model is developed that integrates biochar application and enhanced weathering for large-scale carbon sequestration.“

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