Background color for WARNING safety signs, labels, and tags. Marking hazardous parts of machines with may cut, crush, or otherwise injure. Emphasizing hazards when enclosure doors are open or when gear, belt, or other guards around moving equipment are opened or removed, exposing unguarded hazards. Marking exposed edges of
Bibcode:1995GBioC...9..377C. doi:10.1029/95GB01107. An ice age is a period of long-term reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers.
During this time, North America, Europe and Asia were covered with ice. Saber-toothed tigers became extinct during this period, but they hunted mammoths and other mammals for food. Fun Earth Science Facts for Kids All about Ice Age â Image of the Sea Ice During Ice Age. Scientists believe the Earth has experienced several ice ages with warm and cold periods. Weâre actually in a warm pattern of an ice age right now. Ice ages are caused by several factors.