The Ice Age refers to the prolonged period of reduced temperatures of the atmosphere and the earth’s surface, leading to an expansion of alpine glaciers and polar ice. The pulses of cold climate within an ice age are known as the glacial periods, while the intermittent warm climate is known as an interglacial (Kidskonnect n.d.). The ice age may also refer to the presence of a large size of an ice sheet in the northern and southern hemispheres. The ice age has gone through several stages, and by the second definition, scientists argue that we are currently in the interglacial period of the ice age, called the Pliocene-Quaternary glaciations. The ice age period began more than 2 million years ago during the Pleistocene era. The expansion of glaciers was first discovered by an engineer and geographer, Pierre Martel on his visit to the valley of Chamonix in the Savoy Alps. Since then, several archaeologists, geographers and geologists have discovered several evidences of ice or glacier extension on the earth’s atmosphere. The ice age is caused by the changes in the earth’s orbit and plate tectonic movements which generate waning and waxing of the ice age.
In earth’s history, there have been five major ice ages with large volumes of glaciers expanding over the past 1 million years. The five ice ages include: Huronian, Cryogenian, Andean-Saharan, Karoo Ice Age, and the Quaternary glaciations. Without these ice ages, the earth’s surface is said to be free of ice. The development of ice ages resulted in various physical activities on earth. For example, the Cryogenian ice age which occurred approximately 800 million years ago caused the Cambrian explosion, and Snowball Earth, with ice reaching the equator (Ehlers et al 2016). The Andean-Saharan also caused the reduction of Carbon dioxide and the increase in oxygen levels, leading to the onset of the Karoo Ice Age. The evidence of Karoo Ice Age was found in Karoo region of South Africa where an extensive sheet of polar ice was found 360-260 million years ago. The current Pliocene Ice Age began approximately 2.6 million years ago which began with the spread of glacial ice in the northern hemisphere. Several cycles of glaciations have been experienced since then.
The ice age is important because it causes the reflection of the sun’s rays by the ice, leading to low air temperatures. Furthermore, increased ice in the arctic reduces evaporation and sublimation; hence causing dry precipitation in the Polar Regions compared to the deserts. The low precipitation reduces snowfalls which are common in high altitudes, by causing them to melt during the summer period.
The ice age has also caused changes in the earth’s atmosphere. For example, it has caused changes in the levels of greenhouse gas, which decreased at the beginning of the ice ages, and increased when the ice sheets disappeared (Kidskonnect n.d.). Increase in carbon dioxide levels also reduces the freezing of the ice ages. After an ice age, the earth is warmed by changes in solar insolation and other secondary factors such as the greenhouse gas.
It is important for 2nd graders to learn about the ice age because it enables them to understand the geological factors that affect the changes in climate and physical features as they encounter in their daily lives. It also enables them to learn about the earth and their place in it. They learn about their environment so that they can protect it and appreciate nature. Second graders can understand how glaciations occur, the reasons and the importance of the ice age; hence getting important information about the nature of the earth and how to cope in it.
- Ehlers, Jürgen, Philip D. Hughes, and Philip L. Gibbard. The Ice Age. Chichester, West Sussex: Wiley Blackwell, 2016. Print.
- Kidskonnect. Ice Age Facts and Worksheets. N.D. Web. Accessed from https://kidskonnect.com/history/ice-age/.