[en] The Greenland Ice Sheet (GrIS) will be losing mass at an accelerating pace throughout the 21st century, with a direct link between anthropogenic greenhouse gas emissions and the magnitude of Greenland mass loss. Currently, approximately 60 % of the mass loss contribution comes from surface melt and subsequent meltwater runoff, while 40 % are due to ice calving. In the ablation zone covered by bare ice in summer, most of the surface melt energy is provided by absorbed shortwave fluxes, which could be reduced by solar geoengineering measures. However, so far very little is known about the potential impacts of an artificial reduction of the incoming solar radiation on the GrIS surface energy budget and the subsequent change in meltwater production. By forcing the regional climate model MAR with the latest CMIP6 shared socioeconomic pathways (ssp) future emission scenarios (ssp245, ssp585) and associated G6solar experiment from the CNRM-ESM2-1 Earth System Model, we estimate the local impact of a reduced solar constant on the projected GrIS surface mass balance (SMB) decrease. Overall, our results show that even in case of low mitigation greenhouse gas emissions scenario (ssp585), the Greenland surface mass loss can be brought in line with the medium mitigation emissions scenario (ssp245) by reducing the solar downward flux at the top of the atmosphere by ~40 W/m2 or ~1.5 % (using the G6solar experiment). In addition to reducing global warming in line with ssp245, G6solar also decreases the efficiency of surface meltwater production over the Greenland ice sheet by damping the well-known positive melt-albedo feedback. With respect to a MAR simulation where the solar constant remains unchanged, decreasing the solar constant according to G6solar in the MAR radiative scheme mitigates the projected Greenland ice sheet surface melt increase by 6 %. However, only more constraining geoengineering experiments than G6solar would allow to maintain positive SMB until the end of this century without any reduction in our greenhouse gas emissions.
Research center :
Sphères - SPHERES
Disciplines :
Earth sciences & physical geography
Author, co-author :
Fettweis, Xavier ; Université de Liège - ULiège > Département de géographie > Climatologie et Topoclimatologie
Delhasse, A., Hanna, E., Kittel, C., and Fettweis, X.: Brief communication: CMIP6 does not suggest any atmospheric blocking increase in summer over Greenland by 2100, Int. J. Climatol., 41, 2589-2596, https://doi.org/10.1002/joc.6977, 2021.
Feldmann, J., Levermann, A., and Mengel, M.: Stabilizing theWest Antarctic Ice Sheet by surface mass deposition, Sci. Adv., 5, eaaw4132, https://doi.org/10.1126/sciadv.aaw4132, 2019.
Fettweis, X.: TC, Greenland ice sheet and geoengineering: MAR outputs, Zenodo [data set], https://doi.org/10.5281/zenodo.5024965, 2021.
Fettweis, X., Franco, B., Tedesco, M., van Angelen, J. H., Lenaerts, J. T. M., van den Broeke, M. R., and Gallée, H.: Estimating the Greenland ice sheet surface mass balance contribution to future sea level rise using the regional atmospheric climate model MAR, The Cryosphere, 7, 469-489, https://doi.org/10.5194/tc-7-469-2013, 2013.
Fettweis, X., Hofer, S., Krebs-Kanzow, U., Amory, C., Aoki, T., Berends, C. J., Born, A., Box, J. E., Delhasse, A., Fujita, K., Gierz, P., Goelzer, H., Hanna, E., Hashimoto, A., Huybrechts, P., Kapsch, M.-L., King, M. D., Kittel, C., Lang, C., Langen, P. L., Lenaerts, J. T. M., Liston, G. E., Lohmann, G., Mernild, S. H., Mikolajewicz, U., Modali, K., Mottram, R. H., Niwano, M., No?l, B., Ryan, J. C., Smith, A., Streffing, J., Tedesco, M., van de Berg, W. J., van den Broeke, M., van de Wal, R. S. W., van Kampenhout, L., Wilton, D., Wouters, B., Ziemen, F., and Zolles, T.: GrSMBMIP: intercomparison of the modelled 1980-2012 surface mass balance over the Greenland Ice Sheet, The Cryosphere, 14, 3935-3958, https://doi.org/10.5194/tc-14-3935-2020, 2020.
Franco, B., Fettweis, X., and Erpicum, M.: Future projections of the Greenland ice sheet energy balance driving the surface melt, The Cryosphere, 7, 1-18, https://doi.org/10.5194/tc-7-1-2013, 2013.
Goelzer, H., Nowicki, S., Payne, A., Larour, E., Seroussi, H., Lipscomb, W. H., Gregory, J., Abe-Ouchi, A., Shepherd, A., Simon, E., Agosta, C., Alexander, P., Aschwanden, A., Barthel, A., Calov, R., Chambers, C., Choi, Y., Cuzzone, J., Dumas, C., Edwards, T., Felikson, D., Fettweis, X., Golledge, N. R., Greve, R., Humbert, A., Huybrechts, P., Le clec'h, S., Lee, V., Leguy, G., Little, C., Lowry, D. P., Morlighem, M., Nias, I., Quiquet, A., Rückamp, M., Schlegel, N.-J., Slater, D. A., Smith, R. S., Straneo, F., Tarasov, L., van deWal, R., and van den Broeke, M.: The future sea-level contribution of the Greenland ice sheet: a multimodel ensemble study of ISMIP6, The Cryosphere, 14, 3071-3096, https://doi.org/10.5194/tc-14-3071-2020, 2020.
Hofer, S., Tedstone, A. J., Fettweis, X., and Bamber J.: Cloud microphysics and circulation anomalies control differences in future Greenland melt, Nat. Clim. Change, 9, 523-528, https://doi.org/10.1038/s41558-019-0507-8, 2019.
Hofer, S., Lang, C., Amory, C., Kittel, C., Delhasse, A., Tedstone, A., and Fettweis, X.: Greater Greenland Ice Sheet contribution to global sea level rise in CMIP6, Nat. Commun., 11, 6289, https://doi.org/10.1038/s41467-020-20011-8, 2020.
Irvine, P. J., Keith, D.W., and Moore, J.: Brief communication: Understanding solar geoengineering's potential to limit sea level rise requires attention from cryosphere experts, The Cryosphere, 12, 2501-2513, https://doi.org/10.5194/tc-12-2501-2018, 2018.
Irvine, P., Emanuel, K., He, J., Horowitz, L. W., Vecchi, G., and Keith, D.: Halving warming with idealized solar geoengineering moderates key climate hazards, Nat. Clim. Change, 9, 295-299, https://doi.org/10.1038/s41558-019-0398-8, 2019.
Kravitz, B., Robock, A., Tilmes, S., Boucher, O., English, J. M., Irvine, P. J., Jones, A., Lawrence, M. G., MacCracken, M., Muri, H., Moore, J. C., Niemeier, U., Phipps, S. J., Sillmann, J., Storelvmo, T.,Wang, H., and Watanabe, S.: The Geoengineering Model Intercomparison Project Phase 6 (GeoMIP6): simulation design and preliminary results, Geosci. Model Dev., 8, 3379-3392, https://doi.org/10.5194/gmd-8-3379-2015, 2015.
Le clec'h, S., Charbit, S., Quiquet, A., Fettweis, X., Dumas, C., Kageyama, M., Wyard, C., and Ritz, C.: Assessment of the Greenland ice sheet-atmosphere feedbacks for the next century with a regional atmospheric model coupled to an ice sheet model, The Cryosphere, 13, 373-395, https://doi.org/10.5194/tc-13-373-2019, 2019.
Moore, J. C., Yue, C., Zhao, L., Guo, X., Watanabe, S., and Ji, D.: Greenland ice sheet response to stratospheric aerosol injection geoengineering, Earth's Future, 7, 1451-1463, https://doi.org/10.1029/2019EF001393, 2019.
No?l, B., van Kampenhout, L., Lenaerts, J. T. M., van de Berg,W. J., and van den Broeke, M. R.: A 21st century warming threshold for sustained Greenland ice sheet mass loss, Geophys. Res. Lett., 48, e2020GL090471, https://doi.org/10.1029/2020GL090471, 2021.
O'Neill, B. C., Tebaldi, C., van Vuuren, D. P., Eyring, V., Friedlingstein, P., Hurtt, G., Knutti, R., Kriegler, E., Lamarque, J.-F., Lowe, J., Meehl, G. A., Moss, R., Riahi, K., and Sanderson, B. M.: The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6, Geosci. Model Dev., 9, 3461-3482, https://doi.org/10.5194/gmd-9-3461-2016, 2016.
Séférian, R., Nabat, P., Michou, M., Saint-Martin, D., Voldoire, A., Colin, J., Decharme, B., Delire, C., Berthet, S., Chevallier, M., Sénési, S., Franchisteguy, L., Vial, J., Mallet, M., Joetzjer, E., Geoffroy, O., Guérémy, J.-F., Moine, M.-P., Msadek, R., Ribes, A., Rocher, M., Roehrig, R., Salas-y-Mélia, D., Sanchez, E., Terray, L., Valcke, S., Waldman, R., Aumont, O., Bopp, L., Deshayes, J., ?thé, C., and Madec, G.: Evaluation of CNRM Earth-System model, CNRM-ESM2-1: role of Earth system processes in present-day and future climate, J. Adv. Model. Earth Sy., 11, 4182-4227, https://doi.org/10.1029/2019MS001791, 2019.
Shepherd, J., Caldeira, K., Cox, P., Haigh, J., Keith, D., Launder, B., Mace, G., MacKerron, G., Pyle, J., Rayner, S., Redgwell, C.,Watson, A., Garthwaite, R., Heap, R., Parker, A., andWilsdon, J.: Geoengineering the climate: science, governance and uncertainty, Royal Society Policy Document 10/09, 83 pp., London, 2009.
Smith,W.: The cost of stratospheric aerosol injection through 2100, Environ. Res. Lett., 15, 114004, https://doi.org/10.1088/1748-9326/aba7e7, 2020.
Slater, T., Hogg, A., and Mottram, R.: Ice-sheet losses track highend sea-level rise projections, Nat. Clim. Change, 10, 879-881, https://doi.org/10.1038/s41558-020-0893-y, 2020.
Tedesco, M. and Fettweis, X.: Unprecedented atmospheric conditions (1948-2019) drive the 2019 exceptional melting season over the Greenland ice sheet, The Cryosphere, 14, 1209-1223, https://doi.org/10.5194/tc-14-1209-2020, 2020.
Tilmes, S., MacMartin, D. G., Lenaerts, J. T. M., van Kampenhout, L., Muntjewerf, L., Xia, L., Harrison, C. S., Krumhardt, K. M., Mills, M. J., Kravitz, B., and Robock, A.: Reaching 1.5 and 2.0 C global surface temperature targets using stratospheric aerosol geoengineering, Earth Syst. Dynam., 11, 579-601, https://doi.org/10.5194/esd-11-579-2020, 2020.
van Angelen, J. H., Lenaerts, J. T. M., van den Broeke, M. R., Fettweis, X., and van Meijgaard, E.: Rapid loss of firn pore space accelerates 21st century Greenland mass loss, Geophys. Res. Lett., 40, 2109-2113, https://doi.org/10.1002/grl.50490, 2013.
van de Berg, W. J., van Meijgaard, E., and van Ulft, L. H.: The added value of high resolution in estimating the surface mass balance in southern Greenland, The Cryosphere, 14, 1809-1827, https://doi.org/10.5194/tc-14-1809-2020, 2020.
Visioni, D., MacMartin, D. G., Kravitz, B., Boucher, O., Jones, A., Lurton, T., Martine, M., Mills, M. J., Nabat, P., Niemeier, U., Séférian, R., and Tilmes, S.: Identifying the sources of uncertainty in climate model simulations of solar radiation modification with the G6sulfur and G6solar Geoengineering Model Intercomparison Project (GeoMIP) simulations, Atmos. Chem. Phys. Discuss. [preprint], https://doi.org/10.5194/acp-2021-133, in review, 2021a.
Visioni, D., MacMartin, D. G., and Kravitz, B.: Is turning down the sun a good proxy for stratospheric sulfate geoengineering?, J. Geophys. Res.-Atmos., 126, e2020JD033952, https://doi.org/10.1029/2020JD033952, 2021b.
Zelinka, M. D., Myers, T. A., McCoy, D. T., Po-Chedley, S., Caldwell, P. M., Ceppi, P., Klein, S. A., and Taylor K. : Causes of higher climate sensitivity in CMIP6 models, Geophys. Res. Lett., 47, e2019GL085782, https://doi.org/10.1029/2019GL085782, 2020.
