Why do scientists believe the polar ice is disappearing?

water pollution

global warming

garbage dumping

polar bears are breaking it up

what are the main causes of global warming?

emissions from cars and factories

discharge from water treatment plants

chemicals in the water

hazardous waste buried underground

how do polar bears use ice?

drinking water

food

means of travel

platform for hunting seals

what is one human activity that may be contributing most to melting of the ice?

dumping chemicals in water

driving cars

speeding up soil erosion

mining gold and silver