(ORDO NEWS) — When it comes to climatic disasters, apocalyptic images of the ice age and global warming immediately come to mind. In the history of mankind alone, several dozen cataclysms have occurred, and for the entire time of the existence of our planet, more than one hundred.
However, both the Earth and humanity survived. Today we face a new threat – the trend towards an increase in average temperature is observed around the world.
The biggest climate disasters in the history of the Earth
During its existence, our planet has experienced radical climate change. There were periods when the temperature rose so much that even at the North and South Poles there was no ice left. Dinosaurs appeared in one of these.
There were also opposite eras – ice ages, when the Earth was completely covered with ice. And the activity of volcanoes and solar activity warmed the planet again over time. On the one hand, such global climate changes led to catastrophic consequences for the biosphere and the extinction of most species.
On the other hand, they stimulated the emergence of new organisms and significantly rebuilt them. After all, the crisis forces all living things to change. Let us analyze the most striking examples of natural disasters caused by climate change.
- Early Proterozoic Ice Age or Huronian glaciation. The first ice age began 2.4 billion years ago and lasted 300 million years;
- Cryogeny. The second ice age began 720 million years ago and lasted 85 million years;
- Paleozoic. The third ice age began 460 million years ago and lasted 40 million years;
- Late Paleozoic. This ice age began 360 million years ago and lasted 100 million years;
- Cenozoic. The last ice age began 34 million years ago and continues to this day.
“Great” extinctions are most often associated with climate change. There were five of them, and the most massive was the Permian-Triassic. It happened 252 million years ago. About 60% of families of marine organisms, 80% of genera and up to 90% of species of trilobites, corals, echinoderms and others have disappeared.
According to a popular hypothesis, the trigger for the Permian-Triassic extinction was anomalously large-scale volcanism. Further, the situation only worsened – it is believed that an increase in the Earth’s temperature by about 10 ° C due to the “methane hydrate gun” played a key role.
At a depth of 200 m to 1 km in the seas there are deposits of frozen gas hydrates – methane, the molecules of which are associated with water. Volcanic activity has led to the melting of gas hydrates and their transition to a gaseous state.
The massive release of methane raised the ambient temperature, which also accelerated melting. The greenhouse gas accumulated over the years has caused a sharp increase in temperature and massive extinction. The Permo-Triassic crisis is a clear example of what happens to nature during global warming.
Extinction of the megafauna
The last known extinction occurred about 11,000 years ago. The temperature increased by 6°C in 40-80 years, which led to the extinction of mammoths, woolly rhinoceros, bighorn deer, and other largest mammals and birds.
Frozen, densely planted tundra-steppes have turned into ordinary tundra. Winters became milder, but more snowy, small herbaceous vegetation died. The animals of this area were left without food, and their numbers decreased.
Man also began to experience problems with nutrition, intensified hunting, which further reduced the fauna. People had to adapt.
So, about 10 thousand years BC. e. agriculture appeared. In the regions that avoided global climate change, animals and people did not change. For example, in Africa or South America, agriculture arose much later – in the 2nd millennium BC. e.
How did natural disasters affect the development of mankind
From 10th to 5th millennium BC. e. the earth has been steadily warmer. The tundra was first replaced by sparse coniferous forests, and then by broad-leaved ones. There were no global changes in people’s lives, the way of life remained familiar.
However, about 3-4 thousand years BC. e. the subboreal cold epoch began. The sharp drop in temperature forced people to adapt. It was during this period that the first supercivilizations appeared: Mesopotamian and Ancient Egyptian.
Some scientists attribute these changes to a worsening climate, and the subsequent collapse of empires to warming.
- One of the major cold snaps over the past millennia coincided with the rise of the Roman Empire. And in 300-600 years. n. e. there was a warming, and in 395 the empire collapsed
- Most of the Middle Ages, known in history as a period of stagnation, falls on a period of warming
- From 1312 to 1791, the Little Ice Age begins – a noticeable cooling throughout Eurasia. At this time, the era of the Renaissance and cultural and technological progress falls
- Some researchers even link global warming, which began in 1980, and the collapse of large states
What is happening with global warming today?
The history of the Earth testifies to more extensive climate changes than the current global warming. However, if earlier cataclysms were caused by natural factors, today these processes are influenced by human activity.
Since the 80s, the temperature on the whole Earth has risen insignificantly, by about half a degree, so in some regions and countries we may not notice global warming. But, if we follow its growth since 1860, we will see a change of 1.5 degrees, and this can already lead to:
- Melting ice
- Sea level rise
- Change in the circulation of water and air
Today, the Intergovernmental Panel on Climate Change (IPCC), the United Nations (UN), the UN Specialized Agency for Education, Science and Culture (UNESCO), the World Meteorological Organization (WMO) are studying the problem of global warming. Billions of dollars are allocated to combat these phenomena. Growth rates are constantly being researched:
- Emissions into the environment
- Greenhouse gases into the atmosphere
Scientists build climate models, draw historical analogies, and compare research findings with known paleoclimate data to get the most accurate picture of climate change. They agree that by about 2100 the average temperature on Earth will increase by another 1.5-2°C.
At the same time, 1.5°C is the threshold value, followed by a global change in all ecosystems on the planet. If the temperature rises by 2°C, in less than a hundred years the Earth will no longer be the same as it is now.
What awaits nature and humanity?
Melting ice will increase the amount of water
Scientists suggest that in the next 100 years, water bodies will rise by about three meters. And this means that coastal cities and countries located on the islands can expect flooding. The probability depends on a number of factors that are difficult to calculate.
Let’s look at a historical example. 8 thousand years BC e. the southern half of the North Sea was the dry land known as Doggerland. After the ice age, the glaciers began to melt, and the rise in sea levels gradually reduced the land. At some point under Doggerland began a massive melting of the permafrost.
And the land, comparable in area to the territory of Norway, went under water in 10 years. One of the largest landslides in history has occurred. Such phenomena are difficult to predict, so we cannot say with certainty whether some cities and countries will be under water.
Warming will lead to drought in large areas of Africa and the Middle East
An increase in temperature by 1.5-2°C does not pose a threat to the survival of mankind. But states that will be adversely affected by climate change are unlikely to put up with it. This can lead to massive changes on the political map.
Let us turn again to the climate changes of the previous 5-10 thousand years. When the temperature rose by 1.5-2°C, the natural zones shifted by several hundred kilometers. Where there was a desert, forests appeared, other territories were drained, animals migrated. Natural changes can be predicted, but how a person will behave in these conditions is an open question.
The history of climate catastrophes has shown that the causes of global warming can be both natural and anthropogenic. As already mentioned in one of the examples, earlier the increase in temperature was associated with the melting of gas hydrates and their transition to a gaseous state.
This process was caused by volcanic activity. Today, humans burn fossil fuels, releasing carbon dioxide, methane, nitrous oxide, and other gases into the atmosphere. They raise the temperature of the environment. According to scientists, this is one of the main causes of global warming.
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