The last ice age began more than two million years ago and has not ended yet How is that?

There is no chance of us entering another Ice Age now because the greenhouse gases we put into the atmosphere during the Industrial Age warmed the Earth.

Illustration of the Earth, with the continents in their present form, but with the planet completely iced over.  The snowball Earth hypothesis suggests that, hundreds of millions of years ago, the Earth may have frozen solid like this as a result of severe climate change.  This illustration imagines what the planet might look like were this to happen now.  In this view, we can make out Australia and Asia and part of the Pacific Ocean.

Although some movies might make us believe that ice ages happen overnight, this is not true, as they take thousands of years to form, while millions of years last on Earth. The Earth has gone through 5 major ice ages, the last of which started 2.6 million years ago and is still continuing so far, as the Earth is currently going through a warm interglacial period that occurs between cold glacial periods.

But what ice ages? How does it occur?

How does the ice age happen?

According to ABC News , the Ice Age is the period in which ice covers large areas of the Earth's surface, and these periods last for millions of years as they reshape the features of the Earth's surface.

An ice age occurs when the Earth's temperature drops and the atmosphere becomes a few degrees cooler over a long period of time, and here summer temperatures in the northern hemisphere cannot rise above freezing for years. This means that the snow that falls in the winter does not melt but rather accumulates over time and begins to compress or glaciate into the ice sheets.

The decrease in the temperature of the planet occurs as a result of some external and internal factors. External factors include any change in the Earth's orbit around the Sun and the amount of light and sunlight reaching the Earth. The amount of light reaching the Earth is affected by the Earth's tilt on its axis and the shape of the Earth's orbit as it revolves around the Sun. As for the internal changes, they mean any changes in ocean currents, the composition of the atmosphere and volcanic activities.

According to a study published in the journal Nature and reported by Science Daily, the beginning of the Ice Age is linked to what is known as Milankovitch cycles, a mechanism of climate changes that Milankovitch explained in 1930 when regular changes in the Earth's tilt and orbit combine to affect the amount of radiation Solar exposure to areas on Earth.

When these factors result in the Northern Hemisphere getting less solar radiation in the summer, a new ice age could begin.

How many ice ages?

The number of major ice ages that the planet has gone through is estimated at 5 eras, the first occurred about two billion years ago and lasted about 300 million years, and the last began about 2.6 million years ago and is still continuing until now, which explains why the polar ice caps of the planet so far.

Large ice ages account for about 25 percent of the planet's past billions of years , Michael Sandstrom, a doctoral student in paleoclimatology at Columbia University in New York City, tells livescience . The five major ice ages include:

First: The Huronian Ice Age period, which lasted between 2.1 and 2.4 billion years ago, during which the Earth became colder as a result of the saturation of the atmosphere and water bodies with oxygen. Despite the increase in the brightness of the sun's rays, the excess oxygen led to the removal of methane, which contributes to keeping the Earth at a warm temperature. Snow and ice covered large and vast areas of land and oceans, reaching up to the equator. The Horonian era is the longest in history.

Second: The Cryogenian period, which extended between 720 million to 635 million years ago, and icy deserts dominated the globe in this age. Temperatures near the equator ranged between -43 and -23 degrees Celsius.

Third: The period of glaciation in the Andes and the Andean-Saharan, which extended from 420 million to 450 million years ago.

Fourth: The Late Paleozoic ice age, formerly known as the Karoo Ice Age, and was known by this name for the formation of the ice sheet in the Karoo region in South Africa. It lasted between 335 and 260 million years ago.

Fifth: The Quaternary period, this period extends from 2.6 million years to the present, where the ice sheets are currently concentrated in Greenland and Antarctica. Multiple changes occurred in the environments, climate and sea level on earth during this period, and this ice age is the warmest among the previous eras.

What happens during the ice age?

During the Ice Age, sea level drops dramatically, because a large amount of Earth's water is trapped on land in continental glaciers.

According to the " Space " website , during the last cold glacial period, which began about 115,000 years ago and ended about 11,000 years ago, sea level was 120 meters lower than it is today, huge ice masses covered vast areas of land.

The planet was much cooler than it is now, and the average global temperature was around 8°C, which is 6°C cooler than the global annual average today. Although this difference does not appear to be significant, it has resulted in ice sheets covering most of North America, Canada, northern Europe and all of northern Asia.

Did humans live in the ice age?

According to SPACE, people like us lived during the Ice Age and managed to survive. Since the emergence of the human race about 300,000 years ago in Africa; Humans spread all over the world. During the Ice Age some populations remained in Africa and were not exposed to the severe effects of the cold and others moved to other parts of the world including the cold icy environments of Europe.

On how the human race survived during the Ice Age, some believe it has to do with how well we adapt, how we use social skills, communication skills, harnessing tools, and the ability to move from one place to another.

Are we about to enter another ice age?

The ABC website stated that the beginning of the Ice Age is associated with changes in the Earth's tilt and orbit, and the Earth is scheduled to witness another ice age now, but climate change makes this highly unlikely.

There is no chance of us entering an ice age now because of the greenhouse gases we put into the atmosphere

More specifically, there is no chance that we are entering an ice age now, because the greenhouse gases we put into the atmosphere during the industrial age have warmed the Earth. Although scientists cannot say we prevented the next ice age, humans certainly played an important role.

There's actually a hypothesis that it's not only industrial society that has caused this, but also methane emissions from rice fields since humans began farming on a large scale, Dr Stephen Phipps, a climate scientist at the University of Tasmania told ABC. It has been around for at least 5,000 years.

So it's likely not only greenhouse gas emissions over the past two centuries that kept us from entering the Ice Age, but also greenhouse gas emissions over the past 5,000 years, which helped guide us away from the next ice-cold period.