Earth has entered four great ice ages in its history, but what many people don't know is that we are still in the last ice age.
Ice age, also known as ice age, ice age, is the geological period of the earth's surface covered with large-scale glaciers, the earth's history has appeared four super ice ages, the time scale of the ice age is at least millions of years, in addition to countless Xiaoice periods. The first Great Ice Age known to mankind is called the Hugh Ice Age, which occurred between 2.4 billion years ago and 2.1 billion years ago, which means that the Earth was frozen for 31 years during this period, which is the earliest and longest ice age. The appearance of the Ice Age of Hugh Round almost wiped out the life that had just emerged on Earth.
How did the first Great Ice Age come about? Here we have to mention the first organism on the earth to learn photosynthetic skills of cyanobacteria, although it is called algae, but it does not belong to the algae in the plant, it belongs to prokaryotes like other bacteria, so cyanobacteria may be his real name. Before the emergence of cyanobacteria, there was very little oxygen in the atmosphere, and the organisms at that time were basically anaerobic organisms, relying on the intake of some organic molecules for a living, and even relying on simple chemicals such as sulfates and iron salts to survive, but the emergence of cyanobacteria broke the early ecological balance. By absorbing carbon dioxide and producing oxygen, cyanobacteria increased the concentration of oxygen in the atmosphere from 0.02% to 4% from 2.45 billion years ago to 1.85 billion years ago, which is the famous great oxidation event in geological history. During this period, a large number of anaerobic organisms were killed by oxygen, and the anaerobic archaea that survived could only hide in the oxygen-starved environment and steal their lives. Since the main greenhouse gases in the atmosphere are carbon dioxide and methane, cyanobacteria absorb a large amount of carbon dioxide, and the oxygen released oxidizes methane, so the greenhouse gases are less and less, and the earth cools down sharply, gradually freezing into a snowball.
We all know that the darker the color of objects of the same material, the easier it is to absorb heat, while white absorbs the least amount of heat. After entering the Ice Age, because the Earth was frozen into a white snowball, the amount of sunlight reflected by the Earth became larger and larger, so that the entire Earth system obtained less and less solar energy, coupled with the fact that the Earth's atmosphere carbon dioxide was basically absorbed at that time, it also made this ice age extend indefinitely, if the ice age continues to extend, the Earth will become a lifeless dead ball. Since there is no way to rely on the sun, the earth decides to rely on itself, so the magma inside the earth finally gushes out under the squeeze of the ice layer, so that a large amount of carbon dioxide is sent into the atmosphere, and the earth gradually comes out of the ice age.
This was followed by the Second Aurora Ice Age. This time occurred about 600 million years ago at the end of the Ancient Age, this time the Time of the Great Ice Age occurred on all continents of the world at a slightly different time, and the cause of the Ice Age was similar to the basic principle of the last time, which was the sharp reduction of carbon dioxide that led to the arrival of the Ice Age. The third Great Ice Age occurred during the Carboniferous to Permian period, about 300 million years ago, and this Time the Great Ice Age occurred mainly in the gondwana ancient land. Among them, the occurrence and regression occurred earlier in South America and Africa, and occurred and subsided later in ancient India and Australia. After the glacier retreated, a large area of tongue-tooth plants appeared. The fourth season of glacial age began 2.5 million years ago and has continued to this day, the latest major ice age in earth's history. In the fourth season, the European Alps moon glaciers expanded at least five times, and in China, there were four subglacial periods correspondingly, and modern glaciers covered a total area of about 16.3 million square kilometers, accounting for 11% of the total land area of the earth. China's modern glaciers are mainly distributed in some peak areas of the Himalayas, Kunlun Mountains, Tianshan Mountains, Qilian Mountains, Ganges Mountains and Hengduan Mountains, with a total area of about 57,069 square kilometers.
Many people wonder why we don't feel particularly cold since we are in the ice age. This is because about 8000-10,000 years ago, the world generally warmed up, a large number of glaciers and ice sheets disappeared or contracted, and the earth entered the ice stage, but the glaciers and ice sheets of various continents did not completely disappear. Although a lot of the evidence is something we can see directly now, due to the large number of clues, the academic community has not yet had a clear detail of this Ice Age. However, the development of human civilization is accelerating the process of the end of the ice age, in human production and life, a large amount of carbon dioxide is released, the greenhouse effect is significantly improved, and the temperature is gradually rising. Although the end of the great weapon may be a good thing for many creatures, it may be a disaster for human civilization, the melting of icebergs in the polar regions alone is enough to raise global sea levels by 30 centimeters, and many cities in coastal areas may be submerged, not to mention ancient viruses without glacier seals, as well as harsh climates and extreme weather brought about by rising temperatures, which are huge disasters for human beings. How many degrees do you think the temperature should reach after the Ice Age? What should humans do then?