The ice age is periodic, when will the next ice age come?

2020-12-30 | Xinchu Science Original |

In the past 1 billion years of the earth, the forming ice age accounted for 25% of the time. The earth has experienced 5 ice ages, the longest of which lasted 300 million years, the rest of the ice agesLasts about 100 million years.

Why did the ice age appear?

The appearance of the ice age depends on the earth’s orbit and the earth’s inclination and swing. When the earth is at the aphelion point farthest from the sun and the earth’s inclination increases, this will cause the polar regions to be almost inaccessible to sunlight and the polar temperature will drop.The glacier begins to expand.

There is no continent around Antarctica. The huge ocean will limit the increase of glaciers. Therefore, the ice age glaciers will certainly spread from the North Pole to the south.

As the earth moves around the sun, the Arctic glaciers are not always expanding. Summer glaciers will melt, and winter glaciers will spread south again. As the glaciers grow, the ground’s ability to reflect sunlight becomes stronger, which further reduces the globaltemperature.

Every time winter comes, polar glaciers will be brought closer to the south, and less ice will be melted in summer. The cooled sea water will increase the ability to absorb carbon dioxide, lose greenhouse gases, and the earth will gradually be covered by ice.

Human beings are in the Quaternary Ice Age?

In fact, human beings are already in the cycle of the ice age. The appearance of glaciers at the two poles of the earth is actually a sign of the beginning of the ice age. The Quaternary Ice Age began 2.7 million years ago.

The reasons for the occurrence of the ice age are very complicated. Because of the harsh conditions, it only occurs once every 40,000 years. A longer ice age occurs every 100,000 years. But every ice age begins,The glacier will grow for tens of thousands of years. During this time, the earth will still be in a relatively suitable environment.

According to the normal ice age cycle, the Quaternary ice age will take about 50,000 to 90,000 years to formally enter the ice cover. In theory, the current polar glaciers should have begun to expand outward and open newA round of ice age.

But at present, the glaciers in the polar regions of the earth are not expanding, but are melting. This is because the impact of humans on the earth’s climate has exceeded the natural tolerance of the earth. Maybe humans will let the earth skip the ice age?

Global warming has offset the first glacier expansion?

The key to the global climate is greenhouse gases, of which carbon dioxide is the most important.

In the past 800,000 years, out of every 1 million air molecules on the earth, only 170-280 are carbon dioxide molecules. During the expansion of the ice age, the global carbon dioxide molecules decreased; during the interglacial period in summer, carbon dioxide moleculesincrease.

However, with human activities, the carbon dioxide level in the South Pole of the earth has also reached 400ppm 400 of 1 million air molecules are carbon dioxide molecules, which significantly affects the average temperature of the earth.

The impact of carbon dioxide on global warming is very large, even a small increase will affect the global climate.

At present, the average temperature of the earth has been 5℃ higher than normal, which has almost offset the first glacier expansion during the Quaternary Ice Age, and polar glaciers are still melting, and humans may have skipped the entire ice age.

If this situation does not change, and humans melted all polar glaciers during the Quaternary Ice Age, then the global sea level will increase by at least 60 meters, enough to flood most cities, and the number of humans will be greatly reduced or even extinct.

When the number of humans decreases, the earth's environment will gradually return to a balanced state.

Glaciers have reappeared in the polar regions, sea levels have dropped, and land has resurfaced. Life on land may need to start to evolve again. If the global warming caused by humans really makes humans extinct, then the reborn earth will stillWill humans appear again?


Special statement

This article was uploaded and published on Baidu Know Daily from the media, the author, etc. It only represents the author's views, and does not mean that Baidu knows the views or positions of the daily, and knows that the daily only provides an information publishing platform. Please contact zdribao@baidu.com for cooperation and contributions.

+1 Like it Like

Follow the author

Xinchu Science
Fight for the scientific career!

Know the popular articles in daily newspapers

www.knowledge-daily.com e-mail: k@knowledge-daily.com