1. how would temperature changes in the atmosphere, enough to melt antarctic ice, affect the hydrosphere, lithosphere, and biosphere

The green house gases plays an important role in controlling the overall temperature of the earth. A small increase in the composition (in terms of ppm/ppb) of these green house gases in the atmosphere, such as CO2, water vapour, methane, CFC etc can lead to a subsequent increase in the earth's average temperature, which could be sufficient enough for the melting of the ice at Antarctica.

Thus , it will also be affecting the biosphere as the sea level will rise, surface temperature will increase and life would be difficult to sustain.

                  ppb stands for parts per billion