have the glaciers of the mountains and the polar regions and we have the great ice sheets of greenland and antarctica. the mountains and polar glaziers are particularly sensitive and we have already committed to further melting over the next decade, to hundreds of years. we�*re also going to see more ice loss from the greenland ice sheet over this century. and for the antarctic ice sheet, there is a wide range of possibilities if we limit greenhouse gas emissions. we may be fortunate and have a relatively low contribution to sea—level rise. but if we have very high greenhouse gas emissions and we are unlucky with how sensitive the ice sheet is, we could see very high sea—level rise indeed. could see very high sea-level rise indeed. �* , , indeed. am i right, the message is there is no — indeed. am i right, the message is there is no going _ indeed. am i right, the message is there is no going back— indeed. am i right, the message is there is no going back from - indeed. am i right, the message is there is no going back from some i there is no going back from some change, once they have melted they cannot be refrozen, i assume? but thatis cannot be refrozen, i assume? but that is cautious optimism this could be slowed or even halted, or is that