There are a few very good reasons why the change in the ice mass results in a decline in the populations of penguins. One reason is the penguins food source grows and develops under the the ice masses. Another reason is a loss of habitat for the penguins. When there is less ice, there are fewer krill for the penguins to eat.
Answer:
The lithosphere is the solid, outer part of the Earth. The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth's structure. It is bounded by the atmosphere above and the asthenosphere (another part of the upper mantle)
Simple. Air has mass. And if air has mass it also has weight. You can feel air when the wind blows. Or do an experiment. Weigh an empty container. Then pump it to a vacuum. Weigh it again. The difference is the weight of the air inside.