Question of the reader - the answer of a scientist
Is it possible to predict the climate of the future by studying the climate of the past in Antarctica?
Paleogeographers study the geological past of the Earth - these specialists work with data on how the physical and geographical conditions have historically changed and why this happened. They investigate, among other things, the climate of the past, relate to geological processes - for example, tectonic movements.

Paleogeography is a fundamental science, its practical significance is very indirect. But it is really important to know how everything happened in the past in order to understand what to expect in the future.

In the arsenal of paleogeography, there are many methods - these are methods of isotope analysis, and methods of radiocarbon analysis, and more specific lithological or paleomagnetic methods.

There are methods of obtaining information about the past by studying the remains of living microorganisms - for example, diatoms.

Diatoms are single-celled organisms with a siliceous shell and they can only be seen under a microscope. Their siliceous carapace can persist in the soil at the bottom of the ocean or lake for thousands of years. By examining the soil, by the types of diatoms scientists can determine what the environment was like five or ten thousand years ago. There are, for example, algae that prefer salt water, there are those that prefer fresh water, there are thermophilic ones, and there are cold-loving ones.

Paleogeographers in Antarctica study how sea level changes, how glaciers grow and shrink, how they affect the relief and even the earth's crust, in what climatic circumstances this happens: how water from the ocean passes into ice, how the Earth reacts to these changes. The three main elements of this system are the body of water, ice and the earth's crust, and the attention of paleogeographers is focused on their interaction.

In a simplified way, the investigation process looks like this. Researchers find in sedimentary layers, for example, the remains of a penguin nest - with preserved organic matter. By organic materials, one can determine at what time this nest appeared, and definitely say: five thousand years ago there was neither a glacier nor an ocean. A little further from this place, researchers find a lake and study the layers of bottom sediments: and, for example, if they find fresh sediments in the upper layer, and marine sediments in the lower layer, then it can be assumed that this lake was previously under sea water - and there was no lake, and a niche at the bottom of the ocean. And since this lake probably contains organic materials, an accurate date can be obtained when the sea receded.

If such data are collected, it will be possible to plot sea level changes, reconstruct glacier dynamics, and model the interaction of the ocean, the earth's surface and the ice sheet in the past.

In this system, there are a lot of influencing factors that are difficult to take into account, therefore, it is impossible to completely simulate the process of natural changes. When constructing models in paleogeography, scientists are forced to take into account the biggest and most significant factors, and leave insignificant ones outside the brackets - otherwise the model will simply not work. Due to the constant deduction of minor agents and a lack of knowledge about nature, current models are inaccurate. So the past must be studied continuously - scientists still know very little about it.
All calculations about the future based on the past are based on how much data researchers have.

With regard to climate, scientists have two datasets about Antarctica. The first one is an array of instrumental data obtained over the past hundred years. The second is an array of data about the distant past, which can be obtained only paleogeographically - by excavating, working with ice cores.

One of the modern problems of paleogeography is that the climate data obtained by the first method are compared with the climate data obtained by the second method. But the further into the past, the more smoothed the results are obtained by researchers - there is less data about the past. In this case, climate forecasting directly depends on the amount of data: to predict something, you need to rely on a very long and very accurate series of observations. In the meantime, there is a stable theory based on a number of assumptions. Modern science relies on Lyell's principle: we imagine that the processes in the past went the same way as now, and therefore, when paleogeographers study the layers of the past and find a shell, they assume that there was a sea in this place. What if not? What if, for some reason, everything was completely different?

Since there are the slightest assumptions in the methods, it is impossible to predict the future with high accuracy. Unfortunately, it is impossible to determine how the sea level will rise in the next 5-10 years and how much warmer the Earth will become in 50 years, but it is possible to roughly outline the trajectory of future changes.



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