- Why does air pressure change with altitude?

Atmospheric pressure decreases as the height of a surface above ground level increases. This is because, as the altitude increases: the number of air molecules decreases. the weight of the air decreases.

there is more space between air molecules at higher altitudes  

Explanation:

answer; (d) melting of sea ice;

heat from the core of the earth causes convection currents to occur in the mantle. these currents slowly move the crust around.