Comment on egusphere-2023-370

Abstract

<strong class="journal-contentHeaderColor">Abstract.</strong> In study presented here we focus on the large climate-ice sheet feedbacks on global scales on time scales of 100,000 yrs. We conducted a series of idealised sensitivity experiments under CO₂ and solar radiation reduction scenarios with the Globally Resolved Energy Balance - Ice Sheet Model v1.0 (GREB-ISM v1.0), to study the characteristics of five climate-ice sheet feedbacks, including albedo, snowfall, ice latent heat, topography and sea level feedbacks. We analysed the relative importance of each of these feedbacks on the ice sheet growth and on the climate system (surface temperature). The results indicate that the inclusion of ice sheets will delay the response to the external forcing and facilitate the climate cooling in the high latitude and altitude areas in the Northern Hemisphere, but also causes a small amount of warming elsewhere, due to the blocking of atmospheric heat transport. As for individual feedbacks, the albedo feedback is the most dominant positive feedback in favour of ice sheet build-up and cooler climates, whereas snowfall feedback is the greatest negative feedback that reduces the growth of ice sheets. The large ice latent heat required to melt ice allows to maintain ice sheets from one cold seasons to the next and therefore provides a positive feedback for ice sheet growth. The ice sheets impact on the topography is also a positive feedback but with smaller impact than the albedo feedback. The sea level change influences ice sheets by shifting their location, in particular allowing ice sheets growth in the Arctic Ocean, while reducing it over central north Asia.