Climate changes past and present. The influence of some factors on climate change. Greenhouse effect. Consequences of climate change. Kyoto Protocol

11.1. Climate changes past and present

Climate is a long-term weather regime determined by the geographic latitude of the area, altitude above sea level, remoteness of the area from the ocean, land topography and other factors.

In 1935, at the meteorological congress in Warsaw, it was prescribed that the values ​​averaged over the previous thirty years should be taken as climatic values. Therefore, in 1935, average values ​​of, say, average monthly or average annual temperatures or precipitation for 1901–1930 were adopted as the standard climate. Now the years 1971–2000 are considered as such.

The climate system is the most complex physical system on the planet. It includes all the moving geospheres of the Earth, i.e. the atmosphere, hydrosphere, lithosphere, biosphere, together with man and all his already quite large-scale anthropogenic activities.

The climate of a planet is determined by its mass, distance from the Sun, and atmospheric composition. The Earth's atmosphere consists of 78% nitrogen, 21% oxygen. The remaining 1% is water vapor, CO 2 (0.03–0.04%), ozone, methane, nitrous oxide, etc. They retain part of the heat emitted by the earth’s surface heated by the Sun, and thus act like a blanket, keeping The temperature of the earth's surface is approximately 30 °C higher than what it would be if the atmosphere consisted only of oxygen and nitrogen. This natural system for controlling the Earth's temperature is called natural greenhouse effect. Recently, however, anthropogenic activities have increased levels of major greenhouse gases, altering the atmosphere's ability to absorb energy. A denser blanket of greenhouse gases upsets the balance between incoming and outgoing energy. As a result, it is established on the planet enhanced greenhouse effect, which has extremely adverse consequences.

About three-quarters of the increase in atmospheric CO 2 concentrations in the 1990s. is due to the burning of fossil fuels, and the rest is due to changes in land use, including deforestation (including for agriculture, urban expansion, roads, etc.).

In the past, the Earth's climate has changed more than once. Studies of sedimentary deposits of the earth's crust, determination of the composition of atmospheric air by microscopic air bubbles included in glacier ice, show that over hundreds of millions of years in past geological eras, the climate of our planet was very significantly different from the present one. Just 10,000 years ago, Northern Europe and much of North America were covered in ice. At that time, an ice sheet containing approximately the same volume of ice as modern Antarctica lay over Europe. Over Moscow, the maximum ice thickness was 300–400 m, and the center of the ice sheet was located over Scandinavia. The second Antarctica was located above North America. These ice sheets deposited such a huge amount of water that the level of the World Ocean was 120 m lower than today. This means that all continents, except Antarctica, were connected to each other by land bridges and this was the direct reason for the settlement of Australia and America. It has now been definitely proven that the settlement of America occurred through the so-called Bering Bridge.

Modern climatologists believe that the Bering Strait controls the advance and retreat of ice ages. It happens this way. Due to some still unclear reasons - most likely, a decrease in solar activity - the temperature on the planet decreases, and part of the water in the oceans freezes. Due to a decrease in the volume of liquid water in the World Ocean, the strait is exposed and turns into the Bering Isthmus, preventing the flow of Pacific Ocean waters into the Arctic. At the same time, the level of Arctic waters decreases, which is immediately replenished with warmer water from the Atlantic Ocean - Arctic ice melts, and the isthmus again becomes a strait. The Ice Age is ending. The “close-open” cycles of the strait last for many thousands of years.

As the Earth was liberated from continental shields, a fairly long period began in which the temperature was significantly higher than today: by 1–1.5 ºC. This period was called the Holocene climatic optimum. Even before science appeared, this same period was imprinted in the memory of many generations of people as a “golden” age, taken away from people for the sins they committed. In the epics of any people in the world, in any culture of the world, there is an idea of ​​a “golden” age. This is an age of extremely favorable natural and climatic conditions, and this is exactly what preceded the emergence of human civilization, the same climate that dominated the planet for approximately 4 thousand years (from 9,000 to 5,000 years ago).

Other outstanding climatic events are the so-called warming of Roman times, then again a significant cooling of the era of the Great Migration of Peoples, and then (from what is more or less well known) - this is the peak at the turn of the 1st and 2nd millennium, the so-called medieval climatic optimum. He gained fame, in particular, due to the fact that at this time the settlement of Greenland by the Normans took place.

The temperature dynamics of the Northern Hemisphere in the Holocene (deviations from the 1951–1980 norm) are presented in Fig. 21.As can be seen from the figure , all temperature changes are concentrated in a rather narrow range - 6 ° C - the difference in global temperature between two states of the Earth (glacial and interglacial periods). This is due to the operation of the planet's climate system.

Rice. 21. Temperature dynamics of the Northern Hemisphere in the Holocene (deviations from the norm for 1951–1980) (according to V. Klimenko, 2010)

However, the planet's climate is currently changing rapidly. According to the UN Intergovernmental Panel on Climate Change (IPCC), between 1906 and 2005, the average temperature of the Earth increased by 0.74 degrees Celsius. The IPCC is also confident that this growth will continue in the future. From the last twenty years of the twentieth century. seventeen turned out to be the warmest in the entire history of meteorological observations (starting from the mid-17th century), and 1995 was 0.75 °C warmer than the climate norm at the end of the last century. The reality of warming is currently confirmed by observations of the state of the Earth's polar caps. In particular, American researchers note that over the past 40 years, more than 40 thousand km 3 of polar ice has melted. There is other evidence of climate warming. For example, a team of Swedish climatologists and oceanographers analyzed satellite data from 1978 to 1995, which allows them to determine the state of sea ice in the Arctic. It has been established that over these years the area of ​​floating ice in the Arctic Ocean has decreased by approximately 610 thousand km 2. The freeze-up time on lakes and rivers in the middle and high latitudes of the Northern Hemisphere has decreased by 1–2 weeks over the last century. Thus, Lake Baikal freezes 11 days later and becomes ice-free five days earlier than 100 years ago.

On average, the territory of Russia became warmer by 0.9 °C over 100 years (1901–2000). In the last 50 years, the warming rate has increased to 2.7 °C/100 years, and after 1970 the warming trend has already reached 4 °C/100 years. In Siberia, warming is occurring at a higher rate. In the last 100 years alone, 70% of coastlines have retreated inland, and the level of the World Ocean has risen by an average of 10 to 20 cm. With climate warming, the number and destructive power of typhoons is increasing. Between 1920 and 1970, the world experienced about 40 hurricanes per year. But from about the mid-1980s. the number of hurricanes has doubled.

In the modern world, humanity is increasingly concerned about the issue of global climate change on Earth. In the last quarter of the twentieth century, sharp warming began to be observed. The number of winters with very low temperatures has decreased significantly, and the average surface air temperature has increased by 0.7 °C. The climate has changed naturally over millions of years. Now these processes are happening much faster. It is worth considering that global climate change can lead to dangerous consequences for all humanity. We will talk further about what factors provoke climate change and what the consequences may be.

Earth's climate

The climate on Earth was not constant. It has changed over the years. Changes in dynamic processes on Earth, the influence of external influences and solar radiation on the planet have led to climate changes.

We have known since school that the climate on our planet is divided into several types. Namely, there are four climate zones:

• Equatorial.
• Tropical.
• Moderate.
• Polar.

Each type is characterized by certain value parameters:

• Temperatures.
• Amount of precipitation in winter and summer.

It is also known that climate significantly affects the life of plants and animals, as well as the soil and water regime. It is the climate that prevails in a given region that determines what crops can be grown in the fields and on farmsteads. The settlement of people, the development of agriculture, the health and life of the population, as well as the development of industry and energy are inextricably linked.

Any climate change significantly affects our lives. Let's look at how climate can change.

Manifestations of a changing climate

Global climate change is manifested in deviations of weather indicators from long-term values ​​over a long period of time. This includes not only changes in temperatures, but also the frequency of weather events that go beyond normal and are considered extreme.

There are processes on Earth that directly provoke all kinds of changes in climate conditions, and also indicate to us that global climate change is taking place.

It is worth noting that climate change on the planet is currently occurring very quickly. Thus, the planetary temperature has increased by half a degree in just about half a century.

What factors influence climate

Based on the processes listed above, which indicate climate change, we can identify several factors influencing these processes:

• Changing orbit and changing the Earth's tilt.
• Decrease or increase in the amount of heat in the depths of the ocean.
• Change in solar radiation intensity.
• Changes in relief and location of continents and oceans, as well as changes in their sizes.
• Changes in the composition of the atmosphere, a significant increase in the amount of greenhouse gases.
• Change in albedo of the earth's surface.

All these factors influence the planet's climate. Climate change occurs for a number of reasons, which can be natural and anthropogenic.

Reasons that provoke changes in climatic conditions

Let's consider what causes of climate change are considered by scientists around the world.

1. Radiation coming from the Sun. Scientists believe that the changing activity of the hottest star may be one of the main causes of climate change. The sun develops and from being young and cold it slowly moves into the stage of aging. Solar activity was one of the reasons for the onset of the Ice Age, as well as periods of warming.
2. Greenhouse gases. They provoke a rise in temperature in the lower layers of the atmosphere. The main greenhouse gases are:

3. Changing Earth's orbit leads to a change and redistribution of solar radiation on the surface. Our planet is influenced by the gravity of the moon and other planets.

4. Impact of volcanoes. It is as follows:

• Environmental impact of volcanic products.
• The impact of gases and ash on the atmosphere, and as a consequence on the climate.
• The influence of ash and gases on snow and ice on the peaks, which leads to mudflows, avalanches, and floods.

Passively degassing volcanoes have a global impact on the atmosphere, just like an active eruption. It can cause a global decrease in temperatures, and as a result, crop failure or drought.

Human activity is one of the causes of global climate change

Scientists have long found the main cause of climate warming. This is an increase in greenhouse gases that are released and accumulated in the atmosphere. As a result, the ability of land and ocean ecosystems to absorb carbon dioxide decreases as it increases in the atmosphere.

Human activities affecting global climate change:

Scientists, based on their research, have concluded that if natural causes influenced the climate, the temperature on earth would be lower. It is human influence that contributes to rising temperatures, which leads to global climate change.

Having considered the causes of climate change, let's move on to the consequences of such processes.

Are there any positive aspects of global warming?

Looking for the positives in a changing climate

Considering how much progress has been made, increased temperatures can be used to increase crop yields. At the same time creating favorable conditions for them. But this will be possible only in temperate climate zones.

The advantages of the greenhouse effect include an increase in the productivity of natural forest biogeocenoses.

Global consequences of climate change

What will be the consequences on a global scale? Scientists believe that:

Climate change on Earth will have a significant impact on human health. The incidence of cardiovascular and other diseases may increase.

• A decrease in food production can lead to hunger, especially among the poor.
• The problem of global climate change will, of course, affect the political issue. Conflicts over the right to own fresh water sources may intensify.

We can already see some of the effects of climate change. How will the climate on our planet continue to change?

Forecasts for the development of global climate change

Experts believe that there may be several scenarios for the development of global changes.

1. Global changes, namely temperature increases, will not be drastic. The Earth has a moving atmosphere; thermal energy is distributed throughout the planet due to the movement of air masses. The world's oceans accumulate more heat than the atmosphere. On such a large planet with its complex systems, change cannot happen too quickly. Significant changes will take millennia.
2. Rapid global warming. This scenario is considered much more often. Temperatures have increased by half a degree over the last century, the amount of carbon dioxide has increased by 20%, and methane by 100%. The melting of Arctic and Antarctic ice will continue. The water level in the oceans and seas will become significantly higher. The number of disasters on the planet will increase. The amount of precipitation on Earth will be distributed unevenly, which will increase the areas suffering from drought.
3. In some parts of the Earth, warming will be replaced by short-term cooling. Scientists calculated this scenario based on the fact that the warm Gulf Stream has become 30% slower and can completely stop if the temperature rises a couple of degrees. This may be reflected in severe cooling in Northern Europe, as well as in the Netherlands, Belgium, Scandinavia and in the northern regions of the European part of Russia. But this is only possible for a short period of time, and then warming will return to Europe. And everything will develop according to scenario 2.
4. Global warming will be replaced by global cooling. This is possible when not only the Gulf Stream stops, but also other ocean currents. This is fraught with the onset of a new ice age.
5. The worst scenario is a greenhouse disaster. An increase in carbon dioxide in the atmosphere will contribute to an increase in temperature. This will lead to the fact that carbon dioxide from the world's oceans will begin to move into the atmosphere. Carbonate sedimentary rocks will decompose with an even greater release of carbon dioxide, which will lead to an even greater increase in temperature and decomposition of carbonate rocks in deeper layers. Glaciers will melt quickly, reducing the Earth's albedo. The amount of methane will increase and the temperature will rise, which will lead to disaster. An increase in temperature on earth by 50 degrees will lead to the death of human civilization, and by 150 degrees it will cause the death of all living organisms.

Global climate change on Earth, as we see, can pose a danger to all humanity. Therefore, it is necessary to pay great attention to this issue. It is necessary to study how we can reduce human influence on these global processes.

Climate change in Russia

Global climate change in Russia will not fail to affect all regions of the country. It will reflect both positively and negatively. The residential area will move closer to the north. Heating costs will be significantly reduced, and cargo transportation along the Arctic coast on large rivers will be simplified. In northern regions, melting snow in areas where there was permafrost can lead to serious damage to communications and buildings. Population migration will begin. In recent years, the number of phenomena such as drought, storm winds, heat, floods, and extreme cold has increased significantly. It is not possible to say specifically how warming will affect different industries. The essence of climate change must be studied comprehensively. It is important to reduce the impact of human activities on our planet. More on this later.

How to avoid disaster?

As we saw earlier, the consequences of global climate change can be simply catastrophic. Humanity should already understand that we are able to stop the approaching catastrophe. What needs to be done to save our planet:

Global climate change must not be allowed to get out of control.

The large world community at the UN conference on climate change adopted the UN Framework Convention (1992) and the Kyoto Protocol (1999). What a pity that some countries put their well-being above solving global climate change issues.

The international scientific community has a huge responsibility to determine the trends of climate change in the future and the development of the main directions of the consequences of this change will save humanity from catastrophic consequences. And taking expensive measures without scientific justification will lead to huge economic losses. The problems of climate change concern all of humanity, and they must be solved together.

https://www.site/2018-02-14/chlen_korrespondent_ran_o_klimate_zemli_v_proshlom_i_buduchem_globalnom_poholodanii

“Even Elon Musk, I’m afraid, is not able to change this”

Corresponding Member of the Russian Academy of Sciences on the Earth's climate in past and future global cooling

How did the climate on Earth change in ancient times, and is it possible, using these data accumulated by scientists, to predict what will happen to the planet in the next hundred or thousand years? Nikolai Smirnov, a member of the laboratory of paleoecology at the Institute of Plant and Animal Ecology of the Ural Branch of the Russian Academy of Sciences, corresponding member of the Russian Academy of Sciences, answered these questions within the framework of the “Open Lecture Course of the Russian Academy of Sciences” series. It turned out that it was even hotter in the Urals. Some 70 thousand years ago, in the area of ​​present-day Yekaterinburg, porcupines could be found, and muskrats lived on Pechora. The forecast for the future is also good - polar bears will swim on ice floes over flooded Yekaterinburg, and then porcupines will return again. You just need to have a little patience.

Science is “to judge the design of the engine by the cars passing by”

How important is the past for the present and future? There are a huge number of different statements on this subject. But the question is: what do we need to practically know from the past in order to understand the current situation and predict the future? In fact, the answer is by no means obvious.

Reconstructions of individual stages of the past, which we are also involved in, as we accumulate researched materials, make it possible to establish patterns and dynamics of processes. In this case, we are able to recognize no longer individual periods, but identify patterns of changing stages, the speed of processes and sometimes reasons.

However, the famous paleontologist George Simpson expressed an interesting idea in one of his works back in the 40s of the last century: “Geneticists, looking at how fruit flies frolic in vitro, think that they are studying evolution. And a paleontologist is like a man standing at a busy street crossroads, and believes that he can judge the structure of an internal combustion engine by looking at the cars passing by.” Simply put, in order to understand how living nature works, you need to understand a lot of conditions, and scientists often overestimate their capabilities.

Let's see, maybe Simpson was really right, and we really want too much from science?

What is the “Holocene climate optimum”

First, a little terminology. The Pleistocene is an era of the Quaternary period that began approximately 2.5 million years ago and ended 15 thousand years ago. The late Pleistocene stands out - this is the last ice age, approximately 120 - 15 thousand years ago. Next comes the Holocene - the interglacial period. It began after the Pleistocene and is where we now live. The Holocene, in turn, is also subdivided. Of the Holocene periods, the Atlantic is most often mentioned; 9-6 thousand years ago is the warmest period of the Holocene, which is also called the climatic optimum.

Vice-President of the Russian Academy of Sciences about the synthetic world in which a person of the 21st century lives

The most difficult question: how to understand the dynamics of ongoing processes? Moreover, they have different scales, and different scales, in turn, are based on different mechanisms. So, historical dynamics. These are changes that occur at intervals of hundreds of years. Geographical dynamics. Changes span thousands of years. Characterized by shifts in the boundaries of natural zones. A larger scale is geological dynamics, when new natural zones and climate types arise, causing mass extinctions of species and the emergence of new ones. On this scale we are dealing with a change in the configuration of the continents and the Earth's orbit.

Were there forests in Yamal?

Now, based on ice isotopes from samples taken at the Vostok station in Antarctica, we know about all processes over the past 360 thousand years. They show that the average temperature there ranged from plus 4 to minus 8 degrees Celsius. And it is also clear that this variability is generated by processes associated with changes in the position of our planet’s orbit.

One more sketch. Shift in the northern forest boundary, recorded from data obtained from the Yamal Peninsula. In the Atlantic, the summer boundary extended to 68.5 degrees north latitude. And this is significantly further than it is now. Fossil wood is still found in Yamal. Then it shifts sharply to the south and remains that way now.

Now about processes that have been monitored for hundreds of years. We can track some things quite simply - from photographs. In particular, our specialists have been filming the same place in the Subpolar Urals since 1977. And if the photographs of those years show the tundra, then in the photographs of recent years a decent forest has already grown there. We record the same processes in the Southern Urals along the Taganay ridge, where a serious shift in the upper boundary of the forest in the mountains occurs.

What does this all tell us? I will not delve into climatology; this is a separately developing branch of knowledge. But I will touch on some points. Moreover, many processes are now interpreted in an overly simplified manner. The temperature of the Earth has increased, and accordingly, the forest boundary has shifted. This is often the point. In fact, modern climatology consists of very developed mathematical models that take into account the mass of components of the Earth’s climate and the influence of completely different aspects and factors.

Factors of climate change. First of all, we must mention such a factor as changes in solar activity. Changing Earth's orbital parameters is another factor. Next is a change in the relative position and size of continents and oceans. Changes in the transparency and gas composition of the atmosphere. Volcanic activity. Concentration of gases, including greenhouse gases, and changes in the reflectivity of the Earth's surface. The amount of heat available in the deep ocean.

Now, by the way, it is becoming more and more obvious that it is the ocean that plays a primary role in climate dynamics. And the main thing here is ocean currents, of which only the Gulf Stream is heard. Meanwhile, the Gulf Stream is just one of the branches of the North Atlantic Current, which has changed its characteristics many times. Moreover, it is the Gulf Stream that determines the climate of all of Europe.

What can the bones of a jerboa, lemming or hyena tell us?

Let's return to paleontology. One of the most proven methods for determining past climate changes is the spore-pollen method. Plant pollen settles, falls into sediments, is perfectly preserved there, and by extracting it, the characteristics of ancient vegetation can be restored. It, in turn, marks the natural and climatic conditions of a particular area in a particular period of the past.

Another direction is paleoentomology. From the smallest preserved remains of chitinous insects, experts determine their species and, accordingly, also draw a conclusion about what natural and climatic conditions were there in ancient times. There were four such specialists throughout the USSR; now there are only two left in the country. One of them works at our institute.

Finally, animal bones that we find in ancient layers can tell us a lot. Moreover, the remains of mammals are one of the most widespread types of finds that we manage to make.

What can animal bones tell us? A classic example is the end of the Ice Age, when there was an almost complete extinction of the so-called “giants”: mammoths, woolly rhinoceros, reindeer, giant sloths, and the Don hare. We must understand that there are animal species that are morphologically very specialized and their presence is an indicator of environmental temperature or other climatic conditions.

It is clear that jerboas cannot live in cold climates. The same goes for the porcupine. On the contrary, the arctic fox will not be able to live in a hot zone. One species of lemming, for example, cannot live without green mosses. And green mosses, in turn, need sufficient moisture. Thus, these lemmings are a natural hydrometer. The muskrat is the same - it lives only in a non-freezing aquatic environment. Now its habitat is Don. And when we find the remains of this animal in the Pechora basin, then this is already a reason for an article in a serious academic journal of the Russian Academy of Sciences. Another example is the hyena. This animal is an indicator of saturated biological systems with sufficient food for them.

For example, in the Pleistocene, hyenas lived here, in the Urals, at the latitude of Yekaterinburg and significantly to the north. This is quite difficult to understand. Moreover, at that time large Pleistocene fauna, lemmings and inhabitants of modern steppes lived in one place. Analogs of such a mosaic, mixed tundra-steppe communities, have been preserved in the northeast of our country. Another version is that it was a unique zone that has no analogues now. It is now called the “mammoth steppe”.

Where and when did the last mammoth die?

All this means is that, while dealing with the Ice Age, we were looking for analogues that would allow us to understand the current situation and make a forecast for the future, but we found an absolutely non-analogous example. An example of how difficult it is for science.

Another example of the same thing. The data we have accumulated shows that mammoths lived on Wrangel Island and Chukotka about 3 thousand years ago. Despite the fact that in Western Europe they became extinct about 10 thousand years ago. And the big-horned deer in the Urals lived up to 6 thousand years. This clearly indicates that the process of extinction of the Pleistocene fauna did not occur simultaneously on Earth. This must also be taken into account.

A promising direction now is the study of the DNA of fossil animals. In our country there are no laboratories working well in this area. There is also little abroad for now. But the data that can be obtained is very interesting. For example, studies of the same lemmings showed that 25 thousand years ago there were a lot of haplotypes of this animal. Then the number of haplotypes decreased and by the present period there were absolutely none left.

Our particular surprise was once caused by the discovery of fossil porcupine bones in the Northern Urals with an age of several tens of thousands of years. Such a find can knock any researcher out of the saddle. We began to look into it, and it became clear that we were dealing with another interglacial period. In addition to the porcupine, such species as red wolves lived in the Urals during this period. Now it is listed in the Red Book, and it can only be found in the wild in the Himalayas and India.

Where do we find these bones? First of all, in cave deposits. In the Southern Urals we dug the famous Ignatievskaya cave, where drawings of an ancient man were found. In the Sverdlovsk region there is the Bobylek grotto. Much of what we find has no analogues.

Isotope analysis of bone gives interesting results. For example, we carried out such an analysis for the teeth of a fossil bison from the Bobylek Grotto. Using oxygen isotopes in tooth enamel, we were able to determine the difference between summer and winter temperatures during two years of the life of a 20,000-year-old animal. You can also work with the carbon isotope. As a result, we get a picture of changes in humidity and temperature in ancient times.

“Someday there will be penguins living here.”

So, data about the past - will it help us understand the present and future or, on the contrary, will it harm us? I offer you an unscientific excursion into the future. Moreover, in 100 years I will definitely not exist, and no one will hold me accountable (laughs).

We know for sure that Yekaterinburg is now in a typical interglacial period. It is quite obvious that this will be followed by another ice age. This is the cyclical nature of development. The question remains when this will happen. The Holocene already lasts 10 thousand years. We are suppressing global warming now, but this is only one step away from global cooling. This is despite the anthropogenic impact. I wouldn't be at all surprised if penguins lived here one day. They are still widespread in the Southern Hemisphere almost to the Equator. They only have a little time left to reach us.

True, for now we are still talking about warming. And the worst thing that can happen is the melting of polar ice and rising sea levels. I hope, at least, that in our lifetime we will not see polar bears floating on ice floes over the 1905 area flooded with ocean.

What will summer be like, what even Elon Musk can’t do and what will force people to leave the Urals

Question from the audience: Can your colleagues give an accurate weather forecast - will next year be dry or rainy?

Smirnov: Now without any humor. The head of our dendrochronological laboratory, Stepan Grigorievich Shiyatov, deals with weather issues. He is a professional of the highest class, and for some areas where tree ring results are well read, he has experience in accurate predictions. For example, for the Orenburg region, Shiyatov repeatedly gave conclusions to the authorities that it was useless to sow grain, since there would be a severe drought. The agreement in the forecasts was always very good. However, I don’t know his forecasts for next year.

Question from the audience: You spoke about the inevitable transition from global warming to global cooling, what mechanisms regulate this?

Smirnov: Over the course of 360 thousand years, warming has always been followed by cooling and vice versa. Anthropogenic impact is not able to change this, even Elon Musk, I’m afraid, is not able to change this.

Question from the audience: We have crossed the temperature indicators of the climatic optimum, the Atlantic, is our climate hotter now or colder?

Smirnov: A subtle question. Climate is a general characteristic over a period of time. And we are talking primarily about the climate of the regions. The most sensitive zone to changes in climate regimes is the high latitudes and the Arctic. There are hydrocarbons there, and now this strip is moving into the sphere of geopolitical interests of countries. Where politics begins, there is no smell of science anymore. Yes, ice melting is recorded. But the northern border of the forest has not yet moved particularly anywhere. The important thing is how the gas composition of the atmosphere behaves in response to these temperature fluctuations. There were even several scandals over publications on this topic. The authors have already had to justify that they did not carry out any political orders.

But to answer quite simply, we, of course, are not worried about the biological effects of the New Atlantic. We are still very far from the Atlantic. In the Sverdlovsk region, oaks grow in only three oak forests, but at that time in the southern part of the region they were everywhere. Of course, we also have walnuts growing in the Botanical Garden, but that’s another thing. And one moment. The Atlantic, so you understand, is not the warmest period of all interglacials that have occurred. Before him, in the Mikulin interglacial (110-70 thousand years ago - approx..

Question from the audience: Under what conditions is a sharp global climate change possible and the cycle can go astray?

Smirnov: There are several models that contradict each other. All this is still in the stage of live research and debate by several groups of scientists. There have already been many attacks on the cyclic theory, and there have been proposals to bury it. But there is no escape from such a factor as the tilt of the earth, precession (when the momentum of a body changes its direction in space - approx.. Fundamental patterns of a planetary nature are unlikely to be destroyed. However, there is also the idea that after the Holocene the existing Until now, the trend has been that interglacial periods have become shorter and colder, and glacial stages have been increasingly severe.

Question from the audience: When did ancient man appear in the Middle Urals and when did a suitable climate for this develop?

Smirnov: When I just graduated from university, I was lucky enough to find Paleolithic sites, that is, sites from the mammoth era about 14 thousand years old in several caves in the area of ​​Bagaryak and Sukhoi Log. In the journal “Nature”, on this occasion, I, together with the famous Ural archaeologist Valery Trofimovich Petrin, published an article entitled “Where to look for Paleolithic sites in the Urals?” This question mark remains to this day. For example, in Altai, tens and hundreds of stone tools are found in caves in one pit. In the Ural caves there will be a couple of stone tools for every ten caves excavated. Obviously, our caves were uncomfortable for the people of that time. No one lived there; they used them as places of worship. The same Ignatievskaya Cave in the Southern Urals or Kapovaya Cave. There are many remains of cave bears, but human traces, on the contrary, are few.

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How the climate on our planet changed in previous historical eras.

One way to find out about this is to study the composition of ancient layers of ice.

Professor of the Department of General Ecology, Faculty of Biology, Moscow State University Alexey Gilyarov talks about ice research in Antarctica

- How can you basically find out something about climate changes that happened a long time ago?

There are different ways, but one of the most exciting and accurate ways is to analyze ice cores, that is, columns of ice formed in Antarctica and Greenland that rise to the surface. There are always air bubbles in ice. Ice formed from the precipitation that was present at the time of its formation, and it captured the air of that time. And we have preserved air samples going back many, many thousands of years. In 1999, in the journal Nature, a large group of authors, including our compatriots, published a paper in which they presented data from the analysis of an ice column taken at the Russian Vostok station. This is eastern Antarctica, an area very remote from all coasts, so the situation there is extremely harsh - the average annual temperature is minus 55, and in winter it reaches minus 80.

- Tell us about the methodology for working with ice cores.

Ice is deposited in layers. Snow falls, deposits and forms ice. Ice is precipitation that has frozen over many, many years, almost a million years. 800 thousand years is the longest column in Antarctica. And by lifting a column of this ice core, we can use various subtle methods to determine the content of carbon dioxide in these small air bubbles, which is what interests us most, methane (also a greenhouse gas, we are all also interested in) and other gases, oxygen, and various isotopes.

- How is the age of the ice layer determined?

Age is determined by the rate of ice deposition. The speed at which ice forms is known, there is a certain model. In addition, you can determine the temperature. To do this, they take not air bubbles, but ice around these bubbles, and melt this ice and see what the ratio of ordinary hydrogen and deuterium - heavy hydrogen - is in it. This is because heavier water molecules that condense to fall as rain or snow require less cooling to condense than lighter ones. Molecules containing deuterium are heavier, and accordingly, with less cooling, they already fall to the ground. And those containing ordinary hydrogen are lighter and require stronger cooling. Accordingly, by changing the relative content of deuterium in the ice column, we monitor the progress of temperature changes.

- What results were obtained at the Vostok station?

Firstly, a rhythm was discovered; it is not very distinct, but it is still possible to identify the largest rises in temperature - approximately once every 100 thousand years. It was a column approximately 3.5 kilometers long - this is the thickness of the ice in the “Vostok”, and, accordingly, this ice was formed over 420 thousand years. About once every 100 thousand years there is a rapid rise in temperature - intense warming, and then a slow cooling and a rather long, very cold period. Then again such a rise - and again a long cooling. What is this connected with? This is associated primarily with the so-called Milankovitch cycles.

Ice core study schedule at Vostok station. Above the graphs is the depth in meters, below is the time in years. Blue - change in the concentration of carbon dioxide CO2, red - change in temperature. The peaks of the red line on the graph are the moments of maximum warming.

Milutin Milanković (1879 - 1958) was a Serbian scientist who suggested that the onset of ice ages could be associated with regular changes in the earth's orbit. The orbit becomes either a little more elongated - ellipsoidal, or more circular; then the angle of inclination of the earth’s axis to the ecliptic changes, this also happens regularly, but with a different frequency. In addition, like such a top, the axis of the earth describes such a small cone. Imagine a spinning top, a top that stops and starts wagging back and forth. The Earth also wobbles a little. And these “wiggles” either become larger or smaller. And this too with a strictly defined frequency. The addition of all these components leads to a change in the distribution of solar radiation falling on the Earth, and, accordingly, the amount of heat changes.

- When did the earliest global warming that we know happen?

These warmings were no stronger than the current one - they happen once every 100 thousand years. Judging by the Vostok core, the warming occurred approximately 400 thousand years ago. But the previous ones were weaker than what is happening today.

More recently, in 2004, another very long ice core was obtained at another location, approximately 500 kilometers from the Vostok station, at the Concordia Station of the European Community, as part of a European project. Unfortunately, we do not participate there; the French, Italians, and others are very active there. Already taking into account our experience, they quickly passed through the ice thickness to the rocky base. And having traveled approximately the same three and a bit kilometers, they received a time sweep of almost 800 thousand years. Since it is drier there, there is a drier climate, there was less precipitation and, accordingly, the layers were thinner. What’s remarkable is that just last year these results were also published in the journal Nature, and over the first 400-odd thousand years the course of the curve obtained at the Vostok station was fully confirmed.

- Over all these 800 thousand years, is the warming periodicity of 100 thousand years confirmed?

The cyclicity is somewhat disrupted there. It exists, but it is somewhat disrupted. And this is now the subject of analysis and speculation about what could have interfered. One thing is clear: the Earth is not completely a ball, there are continents, there are oceans, and they are not at all evenly distributed, and all this carries some kind of adjustments to its movement.

On the graphs that were obtained, modern warming looks just like it is from periodic warmings. Does it follow from this that the role of man here may not be so great?

If there were no human activity, warming would still occur.

- Would warming without human participation be the same as we see it now?

This is a big question. Because, in fact, there have not been such high levels of carbon dioxide concentrations as we are seeing now in 700-800 thousand years. They were there in ancient times, but during that time they have never been so high. And the growth rate is also unusually high over the past 100 years.

- Do the concentration of carbon dioxide in the air and temperature change synchronously?

Yes, they change strictly synchronously. The graphs of carbon dioxide concentration and temperature simply run in parallel. The question is, what is the cause and what is the effect? The fact is that the warmer it is, the more CO2 begins to be released during the rotting of organic residues and so on. Therefore, processes reinforce each other, this is positive feedback.

Not long ago there was a report from the universities of Florida, where an international group of ecologists analyzed the concentration of CO2 in the permafrost around the North Pole. Scientists have concluded that permafrost contains more CO2 than the Earth's atmosphere. Can we say that this is a specific situation only for modern global warming or was it typical in previous periods - 300 - 400 thousand years ago?

At the North Pole there is sea ice, that's a completely different story. You need to take ice that lies on land. As far as I know from ice cores, such a high concentration of CO2 has never reached such a high concentration anywhere. Another thing is that it is now very difficult to say how much a person actually influences the increase in CO2 and warming. Because we know exactly and determine only two numbers. We determine the CO2 concentration that is currently observed at different latitudes, at different points, we have learned to measure this exactly. And besides, we know how much carbon dioxide is emitted as a result of burning fossil fuels, we also know this quite accurately. We only know these two numbers for sure; all other numbers are estimates. If all the carbon dioxide produced by burning fossil fuels remained in the atmosphere, its concentration would be significantly higher. She is below. He contacts. But determining the binding sites, or as geochemists say, carbon sinks in the atmosphere is extremely difficult. Because in any natural ecosystem, in any forest or steppe, both the binding of carbon dioxide as a result of plant photosynthesis and the release of primarily fungi and bacteria as a result of respiration occur simultaneously. This happens everywhere. And understanding where these flows go is a very difficult task.

1 Among global environmental problems, the world community puts climate change in first place. Climate change in the history of mankind is one of the most important and at the same time the most natural characteristics of the natural environment. Over 200 million years, the Earth's climate has continuously changed, but never as quickly as it does now. Over the last century, the climate on earth has warmed by 0.5 0 C - an unprecedented fact in the geological history of our planet. Sharp climate change in boreal regions is reflected in a decrease in the number of frosty winters. Over the past 25 years, the average temperature of the surface layer of air has increased by 0.7 0 C. In the equatorial zone it has not changed, but the closer to the poles, the more noticeable the warming.

The global climate is a complex system where the gradual accumulation of quantitative changes can lead to an unexpected qualitative leap with unpredictable consequences.

What causes climate warming? What are the consequences of this phenomenon? Do the current phenomena threaten humanity with catastrophe and what are the ways to solve these problems?

The climate of the planet is determined by the process of heat and mass transfer in the system Sun - atmosphere - ocean - cryosphere - biosphere. The main factors influencing this process are solar activity, Earth's albedo, atmospheric composition, general circulation, and the intensity of processes in the biosphere.

However, global warming observed over the last century, especially over the last 30-50 years, according to the generally accepted opinion, is associated primarily with the strengthening of the “greenhouse effect”. The greenhouse effect is produced by gases that accumulate over decades in the atmosphere, such as water vapor, carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons, which absorb infrared thermal radiation from the surface of the Earth, heated by sunlight. Thanks to these gases, the heat emanating from the earth does not escape into space, but is retained in the atmosphere. As a result, the atmosphere warms up, which is called the greenhouse effect. One should not think that the greenhouse effect is some kind of new, previously unobserved phenomenon. It has been active on Earth since the atmosphere appeared. Without the greenhouse effect, the average temperature of the Earth's surface would be below 0 0 C. Nowadays, this temperature is 10 0 C.

Today, the reason for the rapid increase in the concentration of greenhouse gases in the atmosphere is human economic activity. Among existing greenhouse gases, carbon dioxide plays a predominant role in climate change. The sources of emissions are industry using the combustion of coal, oil, natural gas, as well as transport emissions.

Carbon dioxide is a permanent component of atmospheric air. Its concentration in the pre-industrial era was about 0.03%. However, the intensive growth of industry in the 19th and especially the 20th centuries led to a noticeable increase in the concentration of CO 2 in the atmosphere. According to data from the beginning of the industrial revolution to 1994, the concentration of carbon dioxide in the atmosphere increased by almost 30%. It should be noted that up to 6 Gt C/year is emitted into the atmosphere annually, which has led to an increase in the carbon dioxide content in the atmosphere to 1.5-1.7 ppm per year. In the next 50-100 years, experts predict a doubling of these indicators.

Throughout the geological history of the Earth, climate change has been accompanied by alternating periods of ice ages and warming periods. For example, there was a sharp cooling and drying of the climate that occurred 6400 BC in the territory of Mesopotamia, which caused an agricultural crisis. Around 3200 BC In the same place, paleographic methods record a phase of climate warming that lasted about 100 years. Many settlements and agricultural lands were abandoned, and in the river valleys, on the contrary, the transition to irrigated agriculture began.

As noted, the era of early civilizations is certainly characterized by such significant climate changes that they undoubtedly must have affected all aspects of human activity without exception.

The most important information about the climate of the past comes from fossils, or the imprints of living organisms in sedimentary rocks. Important information can be obtained from data on sea level changes. Recently, the analysis of radioactive isotopes of various elements has become an effective means of studying the climate of the past.

Scientific data have made it possible to reliably establish that over many millions of years, climate changes on the planet have been accompanied by changes in carbon dioxide concentrations. Thus, in the Late Cretaceous, the average temperature was 11.2 0 C higher than the modern one, and the CO 2 content was 2050 ppm. Accordingly, in the Eocene T = 8.2 0 C, 1180 ppm CO 2, in the Miocene T = 60 0 C, 800 ppm CO 2, in the Pliocene T = 4.8 0 C, 460 ppm CO 2. Currently, the CO 2 content is 376 ppm.

The processes of the onset of ice ages over the last million years are caused by a drop in CO 2 content in the atmosphere. According to Henry's law of solubility, feedback may occur, showing an increase in the solubility of CO 2 at low temperatures.

The main means of studying climate and its changes are physical and mathematical models that describe the dynamics of the atmosphere and ocean, the interaction of radiation, cloudiness, aerosols, gas components, and the properties of the earth's surface.

According to these calculations, the global trend of climate change is a catastrophic disruption of climate equilibrium. First of all, warming is predicted, and it will warm more strongly in high latitudes and in the warm season than in low and cold times, respectively, in the Southern Hemisphere the warming should be slightly greater than in the Northern. This could lead to the melting of polar ice, followed by rising sea levels and flooding of low-lying land. The consequences include changes in the atmospheric circulation regime, changes in precipitation patterns, shifts in climate zones and the emergence of new deserts on the planet. We can expect an increase in the instability of weather phenomena due to atmospheric moisture (showers, hurricanes, floods). In addition, it is worth highlighting the socio-economic problems associated with population migration and a significant increase in costs to eliminate the consequences of global warming.

However, even if the impact of carbon dioxide emissions on climate is less than we currently assume, doubling its concentration should cause significant changes in the biosphere. With double the CO 2 content, most cultivated plants grow faster, produce seeds and fruits 8-10 days earlier, the yield is 20-30% higher than in control experiments

Changing the O 2 /CO 2 ratio can have a strong effect on biological equilibrium. The danger is that the simplest types of organisms will adapt most quickly to a sharp change in the composition of the atmosphere; hence the high probability of the emergence of new forms of pathogenic organisms.

Climate warming naturally leads to climate wetting. Over the past 10 years, the amount of precipitation on the planet has increased by 1%.

It is not so much cold and heat that are dangerous, but sudden changes in temperature in different parts of the planet. The land is heating up much faster than the oceans and glaciers, so the winds blowing from the oceans to the continents, carrying large amounts of moisture, are increasing. We are already witnessing that in recent years hurricanes, cyclones, and typhoons have become more frequent and intensified, causing heavy rains, snowfalls, and floods. Simultaneously with the warming of the troposphere, the stratosphere is cooling. Today, global climate change is causing severe droughts in the tropical zone, leading to famine in Somalia, the Philippines, and southern China. Whatever the reason for climate warming, this process is taking place and its consequences are already evident.

To address the potential threat of global climate change, coordination of efforts of the international community, political leaders and relevant experts is necessary. Under the auspices of the UN Environment Program and the World Meteorological Organization, the authoritative Intergovernmental Panel on Climate Change has been functioning since 1988, assessing the available data, the likely consequences of climate change, developing and proposing a response strategy to them. Attention to the issues of global climate change and assessment of the socio-economic consequences have made it possible to conclude a number of conventions and protocols to them at the international level.

The first step in solving this problem was the adoption in 1992 of the United Nations Framework Convention on Climate Change, the purpose of which is to unite efforts to prevent dangerous climate change and stabilize the concentration of greenhouse gases in the atmosphere. Currently, more than 190 countries around the world are parties to the Framework Convention.

Limiting anthropogenic emissions of greenhouse gases into the atmosphere presupposes the creation of an appropriate system of economic relations. The legal side of regulating these issues is reflected in the Kyoto Protocol adopted in 1997, according to which the signatory countries undertake to reduce their total greenhouse gas emissions by at least 5% compared to 1990 levels by 2008-2012. By regulating economic mechanisms for reducing greenhouse gas emissions into the atmosphere, the Protocol does not contain restrictions on any types of activities, as well as penalties. The Kyoto Protocol established greenhouse gas emission quotas for developed countries and countries with economies in transition. It is expected that mechanisms such as greenhouse gas emissions trading will not only help reduce global emissions reduction costs, but will also generate new economic incentives for the introduction of cleaner fuels and energy-saving technologies.

BIBLIOGRAPHY

1. Grubb M., Vrolik K., Brack D. Quito Protocol: Analysis and Interpretation / Trans. from English - M.: Nauka, 2001. - 304 p.
2. Heinz E. Climate changes in the history of time.//Ecology and Life, 2001, No. 1, p. 52-54.
3. Ecology, nature conservation, environmental safety. Under the general editorship. A.T. Nikitina, S.A. Stepanova. -M.: Publishing house MNEPU, 2000. - 648 p.

Bibliographic link

Uvarova N.N. CLIMATE AS A GLOBAL PROBLEM: PAST, PRESENT, FUTURE // Advances in modern natural science. – 2006. – No. 4. – P. 100-102;
URL: http://natural-sciences.ru/ru/article/view?id=10264 (date of access: 08/24/2019). We bring to your attention magazines published by the publishing house "Academy of Natural Sciences"