Final answer:
An ice age is a period of time when Earth's continents are covered with glaciers. It is a long-term climate cycle characterized by colder temperatures and the expansion of ice sheets and glaciers. Scientists once believed that the Earth was heading for another ice age, but the current global warming trend is likely to prevent it.
Step-by-step explanation:
An ice age is a period of time when a large portion of Earth's continents are covered with glaciers. It is a long-term climate cycle characterized by colder temperatures and the expansion of ice sheets and glaciers. Ice ages are caused by a combination of factors, including changes in Earth's orbit, volcanic activities, and the distribution of continents.
During an ice age, the advance and retreat of glaciers shape the landscape, creating features such as moraines, drumlins, and U-shaped valleys. These glacial landforms provide evidence of past ice ages. The most recent ice age, known as the Pleistocene Ice Age, occurred approximately 2.6 million to 11,700 years ago.
In the question, it is mentioned that scientists believed the Earth was heading for another ice age due to apparent global cooling trends. This refers to a hypothesis in the 1970s that suggested a cooling trend could lead to a new ice age. However, further research and understanding of climate change have shown that the current global warming trend will likely prevent the onset of a new ice age.
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