Publication Date:
2019-07-17
Description:
Projections of changes in surface air temperature and global mean sea level over the next century are presented for all IS92 radiative scenarios. A zonal meanenergy-balance climate model is used to estimate temperature changes and thermal expansion, precipitation-dependent sensitivity values are used to estimate thesea-level contribution of glaciers and small ice caps and dynamic ice-sheet models coupled to surface mass balance models are employed with regard to theAntarctic and Greenland ice sheets. A few of the sea-level projections have been included in the IPCC96-report for comparison with the revised IPCC96projections. Here it is demonstrated that the observed inter-model differences are similar for all IS92 radiative forcing scenarios: the projections of global surfaceair temperature change resemble the revised IPCC96 projections. In this paper, the reasons for the inter-model differences in sea-level results are considered. Thelargest inter-model differences in individual sea-level contributions are found for thermal expansion and for the Antarctic ice sheet. Sensitivity experiments arepresented that show the importance of different assumptions about the temperature forcing of the glacier and ice-sheet models and about the weakening of theocean circulation. Furthermore, uncertainties in thermal expansion caused by uncertainties in ocean heat mixing are considered. It is concluded that theinter-model differences in sea-level projections are caused by the use of essentially different models in this paper and in the revised IPCC96 projections.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
Format:
application/pdf
