Why are there different climates on earth? Different climate and geography: how would life have developed? Australia and Oceania

Typically, alternative history explores the consequences of certain decisions that people might have made at certain historical moments. What if we do not live in an absolutely deterministic Universe and can travel even further in time, exploring the possibilities of the existence of a variety of Earths?

If Pangea had never collapsed?

Between three and two hundred million years ago, the world's continents were joined into a monolithic landmass now called Pangea. It gradually crumbled into pieces, forming the continents we know today. At the same time, curious things were happening on the planet. geological stories. For example, India crashing into the lower part of Asia caused the growth of the Himalayas. What would happen if there were no tectonic drift, and Pangea still occupied an entire hemisphere, leaving Tethys, a world ocean of incredible size, on the other?

We probably wouldn't have such diversity biological world. After all, the development of different species implies the presence of geographic isolation, causing selective pressure, leading to the development of fresh genetic traits. The vast majority of the interior of such a continent would be arid. After all, the clouds that carry moisture could not reach the center of such a large piece of land. The excess mass would affect the rotation of our planet, and most of it would end up in the equatorial hot regions.

If we compare it with what we have, the Earth would become a couple of tens of degrees Celsius warmer in summer. This would lead to incredible typhoons due to the extraordinary circulation system in Tethys. After all, only small continental shelves and small island chains could prevent them.

In the second historical period of such a Pangea, the tropics with monsoon regions rich in water would have been inhabited by mammals. Reptiles would have remained primarily in dry, large areas. After all, mammals require much more water. As studies of Pangean fossil sections show, the tropical regions were dominated by the now extinct ancestor of the earliest mammals, the traversodont cynodont. Procolophonoids lived in more temperate regions. These are stocky lizards that vaguely resemble modern turtles.

Different regions of what is now Pangea may well have had a completely different distribution of life: mammals in the humid and hot tropics, pseudoreptiles and reptiles in the temperate and dry regions. Relative stagnation of all environment would hardly allow the emergence of intelligent life. But if lucky, it would have a strong impact on regions with the opposite climate.

What if the earth's axis were not tilted?

Over time, we follow the change of seasons, which is the result of the tilt of the earth's axis. The planet orbits the Sun, and different hemispheres are exposed to different amounts of sunlight. If the earth's axis had not tilted by 23 degrees, daylight in any region of the planet would have lasted about twelve hours, and only at the poles the Sun would have been invariably on the horizon.

The weather would become more uniform, with changes occurring only as a result of changes throughout the year, depending on the distance between the Sun and the Earth. Northern latitudes would be in the grip of eternal winter, and at the equator there would be humid tropics and heavy downpours would occur. To the south or north of the equator there would be areas with perpetual summer, autumn or spring, and also winter. The earth would become less suitable for life as it approached the poles.

Many believe that the Earth's tilt was caused by a collision with a large object, which also caused the formation of the Moon. According to the theory rare earth, this event had a wonderful impact on the development of life. Without axial tilt, the planet may be left without an atmosphere. After all, at the equator gases will evaporate into space due to excessive excess sunlight, while at the poles they will settle and freeze.

Even if life survives in such conditions, they can be destructive for all intelligent species like ours. If there are no seasons, but there are constant tropical downpours, it will be impossible to grow crops in the currently accepted way. It will be difficult for an intelligent species to start an industrial revolution. After all, it was mainly due to technologies that warmed our homes during the cold months of winter.

What if the planet had a different tilt or rotation?

A change in the tilt of the Earth's axis will significantly change the climate and environment. After all, the difference in angle changes the amount of sunlight reaching the planet, as well as the severity of all seasons. If the earth tilted ninety degrees, the changes in seasons would be extreme. In this case, as the planets rotated around the Sun, the poles in turn would end up directly on the Sun, at right angles to it. While one hemisphere would be bathed in high temperatures and sunlight, the other would be in a state of extremely cold darkness.

Three months later, the angle of the poles relative to the Sun would decrease, and the regions of the equator would receive twelve hours of sun and darkness daily, while the Star, rising in the north, set in the south.

It is unlikely that life could develop in such a world due to the annual cycles of summer radiation sterilization and winter deep freezing. True, there are organisms on Earth called extremophiles that can withstand such conditions. If extremophiles could evolve under sufficiently complex living conditions, they would likely have the incredible ability to hibernate or adapt through migration.

Chris Vaillant, a conceptual artist and artist, studied several scenarios for changing the point around which our planet revolves. In one scenario, called "Sea Pole", he tilted the Earth so that both poles were under water and then extrapolated this effect to the climate. It removed the ice caps of Greenland and Antarctica, creating a wetter, warm world with potentially active biomass as well as species diversity.

“Shiveria,” the reverse scenario, involved placing ice caps at two ends of the earth: North America and China. This is done to create a world that is dry and cold. True, Mediterranean tropics would appear in Antarctica.

By turning the globe upside down, you can completely reverse the winds, water flows, and rain manifestations. A world will be created with deserts in place of North America and China, but with an overall more favorable situation for life.

What would happen if South America were an island continent?

From the final Jurassic period Until the period that started three and a half million years ago, South and North America were separated by water. On both continents, independent evolution lasted for almost 160 million years. There was minor biotic exchange across the nascent Caribbean islands 80 million years ago, and through the Central American Peninsula 20 million years ago.

In those days, America, like Australia and South America, was inhabited by marsupials. In addition, there were unusual ungulates, placental animals, and the first camels, among others. The toothless ancestors of anteaters, sloths and armadillos were also here.

All living marsupials actually originate in South America, with the common genetic ancestors of possums and kangaroos. There were probably many borhyaenoid marsupial carnivores among South American marsupials. They reminded saber tooth tigers, dogs, weasels and bears. However, scientists are not yet sure that they carried their young in pouches.

After the connection of the two American continents, mammals from North America spread throughout South America. They displaced most of the marsupial species. Meanwhile, South American birds, reptiles and some mammals moved north.

If these continents had never united, it is likely that many marsupials would have survived by now, creating the environment of an alien, wild Australia. If humans or a similar species had arrived on the southern continent, they would have brought placental mammals from Eurasia, potentially causing an extinction crisis similar to what is happening in modern world with Australian marsupials.

What if the Mediterranean remained closed?

The Strait of Gibraltar closed about six million years ago. The Mediterranean turned out to be connected to the Atlantic only by a couple of small canals. The results were disastrous. With tectonic movement pushing Africa towards Europe, the channel that allowed water to flow out was sealed. However salty water I was still looking for a way out. Mediterranean water began to evaporate without any outlet, creating the vast, very salty Dead Sea. The layer of salt formed at the bottom reaches a height of one and a half kilometers. He provoked the extinction of the main part sea ​​life. This turned out to be the Messinian salinity peak.

Hundreds of thousands of years later, after the Zanclin Flood, the Mediterranean was reconnected to the Atlantic. In the process, the sea quickly filled up, the land passages between North Africa and Europe were flooded, and animal species were isolated on the islands. Here they underwent speciation. The Atlantic sea waters forced them to quickly adapt to the new colonization of the Mediterranean.

What if this never happened, and the Mediterranean remained a real frying pan with dried salt? It is possible that in this case people could reach Europe much earlier, by migrating through the salt flats, without making a significant detour through the Middle East. Salt is a valuable resource. With the development of civilization, cultures living in the region would likely have used this resource for trade with distant territories of Asia and Africa. With salt required for the survival of grain-eating humans, its increasing availability may have led to more successful and rapid development of agriculture in the Western part of the planet. Yet salt may not have been as valuable due to its abundance and symbolic value.

What if there were no significant metal deposits on the planet?

Animals and humans require metals to survive. What would happen if metals like copper were not concentrated in exploited deposits? Or if they were located in regions inaccessible to the first people: on the polar caps or in the ocean?

Of course, the development of more advanced, efficient Stone Age technologies would not have been interrupted. But, apparently, the general vector of development would be closed to humanity or other intelligent life that would arise in such a world.

The transition from the classical Neolithic era would have happened without metals. After all, the agricultural revolution would cause the concentration of population and the creation settlements. The wheel and plow would have revolutionized the lives of Stone Age people, however, the lack of any valuable metals could interrupt the development of trade, mining, even social classes. The presence of complex civilizations in America without metals makes it possible to assume that something similar would be possible in Eurasia. And yet, if metals like silver and gold were not available, the art and economy of such cultures would not be vibrant enough.

The relative absence of metals in Mesoamerica led to the rather ingenious use of obsidian. After all, volcanic glass can be quite fragile, but also sharp, like a modern scalpel. The ancient Aztecs used obsidian to create double-edged swords, knives, arrowheads and spears. Volcanic glass also had deep religious significance. Its natural value became one of the reasons for the Aztecs’ passion for total self-sacrifice. With such sharp blades, the process of cutting off someone's ear or tongue to draw blood during religious rites was not as painful as we think.

Obsidian imported from the Middle East and Ethiopia was also used in Egypt. Its use for creating sickle blades and knives gradually declined during the Predynastic period as metallurgy developed. At the same time, everyone valued obsidian as an artistic material. Without metals, Egyptian civilization may have had a growing interest in obsidian, expanding into East Africa and the Middle East in search of significant sources of volcanic glass. One of the richest European sources of obsidian was the region around the Carpathian Mountains. A whole culture of connoisseurs of glass swords could have appeared here.

We don't know how complex a culture using only ceramics, stone and glass could become. Many advances in food preparation, transportation, and engineering could become impossible. There is no talk of an industrial revolution either. True, such societies are able to make good progress in medicine or astronomy, but they would still hardly be able to reach the Moon.

What if the Sahara remained wet?

Five thousand years ago, the Sahara was a thriving place with meadows and lakes, inhabited by giraffes and hippos. At that time there was a humid African period. But scientists still do not know the approximate dates of its beginning and end. It was precisely this climate that made it possible for the first people from Africa to migrate. Otherwise, the Sahara would have become a significant obstacle. The transition to real desert conditions apparently occurred about three thousand years ago, forcing local residents migrate to regions more suitable for life.

What if such a wet period never ended? At that time, there were several large lakes in the south of Libya. And Lake Chad was much larger. Near these bodies of water, civilizations actively used tools, creating real works of primitive art. They left behind many artifacts and bones, now buried in the inaccessible sands. In 2000, a group of paleontologists was looking for dinosaur bones in the south of Niger, and came across the remains of dozens of bright representatives of the human species. They also found beads, clay shards, stone tools, as well as bones of an incredible number of fish, crocodiles, hippos, mollusks, and turtles.

The expedition that followed three years later was able to discover no less than 173 burial sites. Based on the structure of the skull, these tribes were attributed to the now extinct tribes of the Tenerian and Kiffian cultures. Fossil evidence has shown that the Sudanese desert regions were once home to large herds of fairly large cattle.

Historically, the Sahara became a barrier that separated cultures south of the desert from North African and Mediterranean cultures. And if the technology of the Fertile Crescent did not make it possible to cross the Sahara without problems, most European developments might never appear south of the desert. You would have to create them there yourself.

But at the same time, with the “living” Sahara, settled cities, as well as centralized states, could have developed in this region a very long time ago. The area occupied by civilized peoples would increase, the greatest ancient trade routes. Moreover, the exchange between Eurasia and Africa would increase: cultural, linguistic and genetic. In some regions, the presence of tropical diseases would be a problem. Also, certain crops of the wet Sahara could have had different levels of development. But still, in general, the level of human civilization would become higher. The Sahara could turn out to be a real home for an entire significant civilization like the Chinese. And this would have no less significant consequences for the development of European and Mediterranean civilizations.

What if there was no Gulf Stream?

The Gulf Stream is one of the most important ocean currents located in the northern hemisphere between Florida and Northwest Europe. Carrying warm Caribbean waters across the Atlantic, it warms Europe. Northern Europe without the Gulf Stream could be as cold as Canada at similar latitudes. This system is regulated by the difference in salinity and water temperature. The saltier, colder, and denser waters of the North Atlantic flow southward until they warm up and become less dense. After this they flow back towards the north. This system was repeatedly closed due to the influx of fresh water and changes in the amount of solar energy falling on our planet. The Gulf Stream returned just over eleven and a half millennia ago, at the end of the last ice age. This might not have happened if solar energy was insufficient. Then northwestern Europe would be threatened by ice age conditions for a longer period of time, the Arctic ice cap would increase, as would the Alpine glaciers.

Perhaps this area would become unsuitable for the development of civilization and agriculture. The inhabitants of the European northwest might be more like the Inuit or Sami than the historical civilizations of the world today. Western civilizations would be limited to the Middle East, North Africa and the Mediterranean. There is a plus to this, it might have been too cold for Central Asian tribes like the Mongols and Huns, who swept through like a tornado and slaughtered literally everyone.

An equally interesting scenario would occur if, after the development of a sedentary civilization, the Gulf Stream returned. The ice would then recede, opening up a new frontier for the conquest and colonization of the cramped cities along the southern shore of the Mediterranean.

What if Doggerland still existed?

Before the period that started 8,200 years ago, there was a piece of low-lying land in the North Sea called British Atlantis, or Doggerland. It was a remnant of the great Doggerland, covering almost the entire North Sea region with rolling vast lands, marshes, well-wooded lowlands and valleys, which were inhabited by Mesolithic people. Its inhabitants migrated with the seasons, gathering berries and hunting for survival. In the North Sea, along with the bones of animals, their artifacts are sometimes found. Changes in climate led to the gradual flooding of this region, whose inhabitants had to move on.

The last part of the great Doggerland was located on the site of the present Dogger Bank, lying slightly below the waters of the North Sea. Based on the latest analysis, it is believed that this piece of land was the last. Its inhabitants were destroyed 8,200 years ago by a five-meter tsunami called Sturegga, which in turn was caused by a landslide of three thousand cubic meters of sediment.

What if Dogger Bank had been higher or the Sturegg event had never happened?

If people had managed to survive in this region, they would have greatly influenced the development of civilization, but due to their isolation with some delay. Perhaps the Mesolithic inhabitants would have been driven off the mainland by Neolithic invaders, who in turn, as in the British Isles, would have been driven out by Celtic invaders.

It is likely that later the Celts could have been displaced by the expansion of the Germanic invaders. Indeed, in Doggerland the density of the Celtic population would be less significant than on mainland Europe or the British Isles. The North Germanic settlers of Doggerland could have become cultural intermediaries between British and Norwegian cultures. The Balts, another group that existed but died out or never existed at all in our world, could also colonize Doggerland.

A surviving Doggerland would nonetheless be extremely susceptible to climate change. Global warming would represent for Doggerland a large number of the same problems as for the low-lying Pacific islands. However, a developed and healthy northern European country facing the threat of extinction could have a significant influence on European environmental policy.

What if there was less ice during ice ages?

Stephen Dutch, a fellow at the University of Wisconsin, presented a 2006 Geological American Society study on the likely consequences of less-icy ice ages. He imagined what might have happened if the North American ice sheets had never gone beyond the Canadian border, and the Scandinavian and Scottish ice sheets had never united. The result would appear. The Missouri River would maintain its original course to Hudson Bay. The Ohio River and the Great Lakes would not have formed in principle, and the English Channel would not have existed at all.

In the modern world, after the formation of the Scottish and Scandinavian ice caps, they created a huge periglacial lake that overflowed river system Rhine-Thames and which created the English Channel. If these two caps were not connected, the water would flow in a northerly direction and leave a land bridge connecting continental Europe with England. The historical British defensive advantage over continental Europe would not exist in principle. This would have a significant impact on the settlement, migration, and cultural spread of people throughout the West.

In North America, meanwhile, the absence of ice caps would change the algorithm for the operation of drainage systems. The pre-Pleistocene River Teas would still exist. The ancient advantage would have been retained by the Niagara River. In this case, the famous Niagara Falls would not exist. The easiest crossing of the Appalachian Mountains would be the St. Lawrence River. Thus, the structure of colonization would change greatly. Meanwhile, changes in the Missouri River would erase the convenient waterways to the west from the east that Clark and Lewis had used for expeditions.

The reduction in the number of water shipping routes would lead to a significant slowdown in the expansion of European invaders across the North American continent. They would probably head through the north. The result could be people resembling a mixture of two cultures: French and English. And perhaps we cannot even imagine such people!

Climatic conditions can change and transform, but general outline they remain the same, making some regions attractive for tourism and others difficult to survive. It is worth understanding the existing species for a better understanding of the geographical features of the planet and a responsible attitude towards the environment - humanity may lose some of the belts in the course of global warming and other catastrophic processes.

What is climate?

This definition means steady weather conditions that distinguishes a particular area. It is reflected in the complex of all changes observed in the territory. Types of climate influence nature and determine the state water bodies and soils, lead to the appearance of specific plants and animals, and affect the development of sectors of the economy and agriculture. Formation occurs as a result of exposure to solar radiation and winds in combination with the variety of surface. All these factors directly depend on geographic latitude, which determines the angle of incidence of the rays, and therefore the volume of heat received.

What influences the climate?

They can determine what the weather will be like different conditions(in addition to geographic latitude). For example, proximity to the ocean has a strong impact. The further the territory is from big waters, the less precipitation it receives, and the more uneven it is. Closer to the ocean, the amplitude of fluctuations is small, and all types of climate in such lands are much milder than continental ones. Sea currents are no less significant. For example, they warm the coast of the Scandinavian Peninsula, which promotes the growth of forests there. At the same time, Greenland, which has a similar location, is covered with ice all year round. Strongly influences climate formation and relief. The higher the terrain, the lower the temperature, so the mountains can be cold even if they are in the tropics. In addition, the ridges can hold back, causing a lot of precipitation to fall on the windward slopes, while further on the continent there is noticeably less rainfall. Finally, it is worth noting the impact of winds, which can also seriously transform climate types. Monsoons, hurricanes and typhoons carry moisture and significantly influence the weather.

All existing types

Before studying each type separately, it is worth understanding the general classification. What are the main types of climate? The easiest way to understand this is to use the example of a specific country. Russian Federation It occupies a large area, and the weather varies greatly throughout the country. The table will help you study everything. The types of climates and the places where they prevail are distributed in it according to each other.

Continental climate

This weather prevails in regions located further beyond the maritime climate zone. What are its features? The continental type of climate is characterized by sunny weather with anticyclones and an impressive amplitude of both annual and daily temperatures. Here summer quickly gives way to winter. Continental climate type can be further divided into moderate, harsh and normal. The best example is the central part of Russia.

Monsoon climate

This type of weather is characterized by a sharp difference in winter and summer temperatures. In the warm season, the weather is formed under the influence of winds blowing onto land from the sea. Therefore, in summer the monsoon type of climate resembles a maritime one, with heavy rains, high clouds, humid air and strong winds. Winter direction air masses is changing. Monsoon type The climate is beginning to resemble continental - with clear and frosty weather and minimal precipitation throughout the season. Such options natural conditions characteristic of several Asian countries - found in Japan, the Far East and northern India.

On Earth, it determines the nature of many features of nature. Climatic conditions also greatly influence life, economic activity people, their health and even biological features. At the same time, climates individual territories do not exist separately. They are parts of a single atmospheric process for the entire planet.

Climate classification

Earth's climates, which have similar features, are combined into certain types, which replace each other in the direction from the equator to the poles. In each hemisphere there are 7 climatic zones, of which 4 are main and 3 are transitional. This division is based on the distribution of air masses around the globe with different properties and characteristics of air movement in them.

In the main belts, one air mass is formed throughout the year. In the equatorial zone - equatorial, in the tropical - tropical, in the temperate - air of temperate latitudes, in the Arctic (Antarctic) - arctic (Antarctic). The transitional zones located between the main ones are alternately entered in different seasons of the year from the adjacent main belts. Here, conditions change seasonally: in summer they are the same as in the neighboring warmer zone, in winter they are the same as in the neighboring colder zone. Along with the change in air masses in the transition zones, the weather also changes. For example, in the subequatorial zone, hot and rainy weather prevails in summer, and cooler and drier weather in winter.

The climate within the belts is heterogeneous. Therefore, belts are divided into climatic regions. Above the oceans, where sea air masses are formed, there are areas of oceanic climates, and above the continents - continental climates. In many climatic zones on the western and eastern coasts of the continents, special types of climate are formed, differing from both continental and oceanic. The reason for this is the interaction of marine and continental air masses, as well as the presence of ocean currents.

Hot ones include and. These areas constantly receive a significant amount of heat due to the large angle of incidence sun rays.

In the equatorial belt, the equatorial air mass dominates throughout the year. The heated air constantly rises in conditions, which leads to the formation of rain clouds. There is heavy rainfall here every day, often with . The amount of precipitation is 1000-3000 mm per year. This is more than the amount of moisture that can evaporate. The equatorial zone has one season of the year: always hot and humid.

In tropical zones, a tropical air mass dominates throughout the year. In it the air descends from upper layers troposphere to the earth's surface. As it descends, it heats up, and even over the oceans no clouds form. Clear weather prevails, in which the sun's rays strongly heat the surface. Therefore on land average in summer higher than in the equatorial zone (up to +35 ° WITH). Winter temperatures are lower than summer temperatures due to a decrease in the angle of incidence of sunlight. Due to the lack of clouds, there is very little rainfall throughout the year, so tropical deserts are common on land. These are the hottest areas of the Earth, where temperature records are recorded. The exception is the eastern shores of the continents, which are washed by warm currents and are influenced by trade winds blowing from the oceans. Therefore, there is a lot of rainfall here.

The territory of subequatorial (transitional) belts is occupied by a humid equatorial air mass in summer, and dry tropical air in winter. Therefore, there are hot and rainy summers and dry and also hot - due to the high position of the Sun - winter.

Temperate climate zones

They occupy about 1/4 of the Earth's surface. They have sharper seasonal differences in temperature and precipitation than hot zones. This is due to a significant decrease in the angle of incidence of sunlight and increased complexity of circulation. They contain air of temperate latitudes all year round, but there are frequent intrusions of arctic and tropical air.

The Southern Hemisphere is dominated by an oceanic temperate climate with cool summers (from +12 to +14 °C), mild winters (from +4 to +6 °C) and heavy precipitation (about 1000 mm per year). In the Northern Hemisphere, large areas are occupied by continental temperate and. His main feature- pronounced changes in temperature across seasons.

To the western shores of the continents all year round Moist air comes from the oceans, brought from the western temperate latitudes, and there is a lot of precipitation here (1000 mm per year). Summers are cool (up to + 16 °C) and humid, and winters are wet and warm (from 0 to +5 °C). Moving from west to east into the interior of the continents, the climate becomes more continental: the amount of precipitation decreases, summer temperatures increase, and winter temperatures decrease.

A monsoon climate is formed on the eastern shores of the continents: summer monsoons bring heavy precipitation from the oceans, and winter monsoons, blowing from the continents to the oceans, are associated with frosty and drier weather.

The subtropical transition zones receive air from temperate latitudes in winter, and tropical air in summer. For mainland sub tropical climate and is characterized by hot (up to +30 °C) dry summers and cool (from 0 to +5 °C) and somewhat wetter winters. There is less precipitation per year than can evaporate, so deserts and deserts predominate. There is a lot of precipitation on the coasts of the continents, and on the western shores it is rainy in winter due to westerly winds from the oceans, and on the eastern shores it is rainy in summer due to the monsoons.

Cold climate zones

During the polar day the earth's surface receives little solar heat, and during the polar night it does not heat up at all. Therefore, the Arctic and Antarctic air masses are very cold and contain little. The Antarctic continental climate is the most severe: exceptionally frosty winters and cold summers with sub-zero temperatures. Therefore, it is covered by a powerful glacier. In the Northern Hemisphere, the climate is similar, and above it is Arctic. It is warmer than Antarctic waters, since ocean waters, even covered with ice, provide additional heat.

In the subarctic and subantarctic zones, the Arctic (Antarctic) air mass dominates in winter, and air of temperate latitudes in summer. Summers are cool, short and humid, winters are long, harsh and with little snow.

Climate- This is a long-term weather regime characteristic of a particular area. It manifests itself in the regular change of all types of weather observed in this area.

Climate influences living and inanimate nature. Water bodies, soil, vegetation, and animals are closely dependent on climate. Certain sectors of the economy, primarily agriculture, are also very dependent on climate.

The climate is formed as a result of the interaction of many factors: the amount of solar radiation reaching the earth's surface; atmospheric circulation; the nature of the underlying surface. At the same time, climate-forming factors themselves depend on the geographical conditions of a given area, primarily on geographical latitude.

The geographic latitude of the area determines the angle of incidence of the sun's rays, obtaining a certain amount of heat. However, receiving heat from the Sun also depends on proximity to the ocean. In places far from the oceans, there is little precipitation, and the precipitation regime is uneven (more in the warm period than in the cold), cloudiness is low, winters are cold, summers are warm, and the annual temperature range is large. This climate is called continental, as it is typical for places located in the interior of continents. A maritime climate is formed over the water surface, which is characterized by: a smooth variation in air temperature, with small daily and annual temperature amplitudes, large clouds, and a uniform and fairly large amount of precipitation.

The climate is also greatly influenced by sea ​​currents. Warm currents warm the atmosphere in the areas where they flow. For example, the warm North Atlantic Current creates favorable conditions for the growth of forests in the southern part of the Scandinavian Peninsula, while most of the island of Greenland, which lies at approximately the same latitudes as the Scandinavian Peninsula, but is outside the zone of influence warm current, is covered with a thick layer of ice all year round.

A major role in climate formation belongs to relief. You already know that with every kilometer the terrain rises, the air temperature drops by 5-6 °C. Therefore, on the high mountain slopes of the Pamirs the average annual temperature- 1 °C, although it is located just north of the tropics.

The location of mountain ranges greatly influences the climate. For example, the Caucasus Mountains trap moist sea winds, and their windward slopes facing the Black Sea receive significantly more precipitation than their leeward slopes. At the same time, the mountains serve as an obstacle to cold northern winds.

There is a dependence of climate on prevailing winds. On the territory of the East European Plain, westerly winds, coming from Atlantic Ocean Therefore, winters in this area are relatively mild.

Districts Far East are under the influence of monsoons. In winter, winds from the interior of the mainland constantly blow here. They are cold and very dry, so there is little precipitation. In summer, on the contrary, winds bring a lot of moisture from the Pacific Ocean. In autumn, when the wind from the ocean subsides, the weather is usually sunny and calm. This best time years in this area.

Climatic characteristics are statistical inferences from long-term weather observation series (in temperate latitudes 25-50-year series are used; in the tropics their duration may be shorter), primarily on the following basic meteorological elements: atmospheric pressure, wind speed and direction, temperature and air humidity, cloudiness and precipitation. They also take into account the duration of solar radiation, visibility range, temperature of the upper layers of soil and water bodies, evaporation of water from the earth’s surface into the atmosphere, height and condition of snow cover, various atmospheric phenomena and ground hydrometeors (dew, ice, fog, thunderstorms, snowstorms, etc.). In the 20th century climatic indicators included characteristics of the elements of the heat balance of the earth's surface, such as total solar radiation, radiation balance, heat exchange between earth's surface and atmosphere, heat loss for evaporation. Complex indicators are also used, i.e. functions of several elements: various coefficients, factors, indices (for example, continentality, aridity, moisture), etc.

Climate zones

Long-term average values ​​of meteorological elements (annual, seasonal, monthly, daily, etc.), their sums, frequency, etc. are called climate standards: corresponding values ​​for individual days, months, years, etc. are considered as a deviation from these norms.

Maps with climate indicators are called climatic(temperature distribution map, pressure distribution map, etc.).

Depending on the temperature conditions, prevailing air masses and winds are distinguished climatic zones.

The main climatic zones are:

• equatorial;
• two tropical;
• two moderate;
• Arctic and Antarctic.

Between the main zones there are transitional climatic zones: subequatorial, subtropical, subarctic, subantarctic. In transitional zones, air masses change seasonally. They come here from neighboring zones, so the climate subequatorial belt in summer it is similar to the climate of the equatorial zone, and in winter - to the tropical climate; The climate of the subtropical zones in summer is similar to the climate of the tropical zones, and in winter - to the climate of the temperate zones. This is due to the seasonal movement of atmospheric pressure belts over the globe following the Sun: in summer - to the north, in winter - to the south.

Climatic zones are divided into climatic regions. So, for example, in tropical zone Africa is divided into areas of tropical dry and tropical humid climate, and in Eurasia the subtropical zone is divided into areas of Mediterranean, continental and monsoon climate. In mountainous areas, an altitudinal zone is formed due to the fact that the air temperature decreases with height.

Diversity of Earth's climates

The climate classification provides an orderly system for characterizing climate types, their zoning and mapping. Let us give examples of climate types that prevail over vast territories (Table 1).

Arctic and Antarctic climate zones

Antarctic and arctic climate dominates in Greenland and Antarctica, where average monthly temperatures are below O °C. Into the dark winter time During the year, these regions receive absolutely no solar radiation, although there are twilights and auroras. Even in summer, the sun's rays hit the earth's surface at a slight angle, which reduces the efficiency of heating. Most of the incoming solar radiation is reflected by the ice. In both summer and winter, the higher elevations of the Antarctic Ice Sheet experience low temperatures. The climate of the interior of Antarctica is much colder climate Arctic, because southern mainland is different large sizes and altitudes, and the Arctic Ocean moderates the climate, despite the widespread distribution of pack ice. During short periods of warming in summer, drifting ice sometimes melts. Precipitation on ice sheets falls in the form of snow or small particles of freezing fog. Inland areas receive only 50-125 mm of precipitation annually, but the coast can receive more than 500 mm. Sometimes cyclones bring clouds and snow to these areas. Snowfalls are often accompanied strong winds, which carry significant masses of snow, blowing it off the slope. Strong katabatic winds with snowstorms blow from the cold glacial sheet, carrying snow to the coast.

Table 1. Climates of the Earth

Climate type	Climate zone	Average temperature, °C		Mode and amount of atmospheric precipitation, mm	Atmospheric circulation	Territory
Equatorial	Equatorial			During a year. 2000	Warm and humid equatorial air masses form in areas of low atmospheric pressure	Equatorial regions of Africa, South America and Oceania
Tropical monsoon	Subequatorial			Mainly during summer monsoon, 2000		South and Southeast Asia, Western and Central Africa, Northern Australia
tropical dry	Tropical			During the year, 200		North Africa, Central Australia
Mediterranean	Subtropical			Mainly in winter, 500	In summer there are anticyclones at high atmospheric pressure; in winter - cyclonic activity	Mediterranean, Southern coast of Crimea, South Africa, South Western Australia, Western California
Subtropical dry	Subtropical			During a year. 120	Dry continental air masses	Interiors of continents
Temperate marine	Moderate			During a year. 1000	Western winds	Western parts of Eurasia and North America
Temperate continental	Moderate			During a year. 400	Western winds	Interiors of continents
Moderate monsoon	Moderate			Mainly during the summer monsoon, 560		Eastern edge of Eurasia
Subarctic	Subarctic			During the year, 200	Cyclones predominate	Northern edges of Eurasia and North America
Arctic (Antarctic)	Arctic (Antarctic)			During the year, 100	Anticyclones predominate	The Arctic Ocean and mainland Australia

Subarctic continental climate is formed in the north of the continents (see climate map of the atlas). In winter, arctic air predominates here, which forms in areas of high pressure. Arctic air spreads to the eastern regions of Canada from the Arctic.

Continental subarctic climate in Asia is characterized by the largest globe annual amplitude of air temperature (60-65 °C). The continental climate here reaches its maximum value.

The average temperature in January varies across the territory from -28 to -50 °C, and in the lowlands and basins due to stagnation of air, its temperature is even lower. In Oymyakon (Yakutia), a record negative air temperature for the Northern Hemisphere was recorded (-71 °C). The air is very dry.

Summer in subarctic belt although short, it is quite warm. The average monthly temperature in July ranges from 12 to 18 °C (daytime maximum is 20-25 °C). During the summer, more than half of the annual precipitation falls, amounting to 200-300 mm on the flat territory, and up to 500 mm per year on the windward slopes of the hills.

The climate of the subarctic zone of North America is less continental compared to the corresponding climate of Asia. Less here Cold winter and colder summers.

Temperate climate zone

Temperate climate of the western coasts of the continents has pronounced features of a marine climate and is characterized by the predominance of marine air masses throughout the year. It is observed on the Atlantic coast of Europe and the Pacific coast of North America. The Cordillera is a natural boundary separating the coast with a maritime climate from inland areas. The European coast, except Scandinavia, is open to free access sea ​​temperate air.

The constant transport of sea air is accompanied by large clouds and causes long springs, in contrast to the interior of the continental regions of Eurasia.

Winter in temperate zone It's warm on the western coasts. The warming influence of the oceans is enhanced by warm sea currents washing the western shores of the continents. The average temperature in January is positive and varies across the territory from north to south from 0 to 6 °C. When arctic air invades, it can drop (on the Scandinavian coast to -25 °C, and on the French coast - to -17 °C). As tropical air spreads northward, the temperature rises sharply (for example, it often reaches 10 °C). In winter, on the western coast of Scandinavia, large positive temperature deviations from the average latitude (by 20 °C) are observed. The temperature anomaly on the Pacific coast of North America is smaller and amounts to no more than 12 °C.

Summer is rarely hot. The average temperature in July is 15-16 °C.

Even during the day, the air temperature rarely exceeds 30 °C. Due to frequent cyclones, all seasons are characterized by cloudy and rainy weather. Especially a lot cloudy days happens on the west coast of North America, where cyclones are forced to slow down their movement in front of the Cordillera mountain systems. In connection with this, great uniformity characterizes the weather regime in southern Alaska, where there are no seasons in our understanding. Eternal autumn reigns there, and only plants remind of the onset of winter or summer. Annual precipitation ranges from 600 to 1000 mm, and on the slopes of mountain ranges - from 2000 to 6000 mm.

In conditions of sufficient moisture, broad-leaved forests develop on the coasts, and in conditions of excess moisture, coniferous forests develop. The lack of summer heat reduces the upper limit of the forest in the mountains to 500-700 m above sea level.

Temperate climate of the eastern coasts of the continents has monsoonal features and is accompanied seasonal change winds: in winter, north-western currents predominate, in summer - south-eastern ones. It is well expressed on the eastern coast of Eurasia.

In winter, with the north-west wind, cold continental temperate air spreads to the coast of the mainland, which is the reason for the low average temperature of the winter months (from -20 to -25 ° C). Clear, dry, windy weather prevails. There is little precipitation in the southern coastal areas. The north of the Amur region, Sakhalin and Kamchatka often fall under the influence of cyclones moving over the Pacific Ocean. Therefore, in winter there is a thick snow cover, especially in Kamchatka, where its maximum height reaches 2 m.

In summer, temperate sea air spreads along the Eurasian coast with a southeast wind. Summers are warm, with an average July temperature of 14 to 18 °C. Frequent precipitation is caused by cyclonic activity. Their annual quantity is 600-1000 mm, with most of them falling in summer. Fogs are common at this time of year.

Unlike Eurasia, the east coast of North America is characterized by monkfish climate, which are expressed in the predominance of winter precipitation and marine type annual variation of air temperature: the minimum occurs in February, and the maximum in August, when the ocean is warmest.

The Canadian anticyclone, unlike the Asian one, is unstable. It forms far from the coast and is often interrupted by cyclones. Winter here is mild, snowy, wet and windy. IN snowy winters the height of the snowdrifts reaches 2.5 m. With a southerly wind, there is often black ice. Therefore, some streets in some cities in eastern Canada have iron railings for pedestrians. Summer is cool and rainy. Annual precipitation is 1000 mm.

Temperate continental climate most clearly expressed on the Eurasian continent, especially in the regions of Siberia, Transbaikalia, northern Mongolia, as well as in the Great Plains in North America.

A feature of the temperate continental climate is the large annual amplitude of air temperature, which can reach 50-60 °C. IN winter months With a negative radiation balance, the earth's surface cools. The cooling effect of the land surface on the surface layers of air is especially great in Asia, where in winter a powerful Asian anticyclone forms and partly cloudy, windless weather prevails. The temperate continental air formed in the area of ​​the anticyclone has a low temperature (-0°...-40 °C). In valleys and basins, due to radiation cooling, the air temperature can drop to -60 °C.

In midwinter, the continental air in the lower layers becomes even colder than the Arctic air. This one is very cold air The Asian anticyclone extends to Western Siberia, Kazakhstan, and southeastern regions of Europe.

The winter Canadian anticyclone is less stable than the Asian anticyclone due to the smaller size of the North American continent. Winters here are less severe, and their severity does not increase towards the center of the continent, as in Asia, but, on the contrary, decreases somewhat due to the frequent passage of cyclones. Continental temperate air in North America has more high temperature than continental temperate air in Asia.

The formation of a continental temperate climate is significantly influenced by the geographical features of the continents. In North America, the Cordillera mountain ranges are a natural boundary separating the maritime coastline from the continental inland areas. In Eurasia, a temperate continental climate is formed over a vast expanse of land, from approximately 20 to 120° E. d. Unlike North America, Europe is open to the free penetration of sea air from the Atlantic deep into its interior. This is facilitated not only by the westerly transport of air masses, which dominates in temperate latitudes, but also by the flat nature of the relief, highly rugged coastlines and deep penetration into the land of the Baltic and North Seas. Therefore, a temperate climate of a lesser degree of continentality is formed over Europe compared to Asia.

In winter, sea Atlantic air moving over the cold land surface of temperate latitudes of Europe retains its properties for a long time. physical properties, and its influence extends throughout Europe. In winter, as the Atlantic influence weakens, the air temperature decreases from west to east. In Berlin it is 0 °C in January, in Warsaw -3 °C, in Moscow -11 °C. In this case, the isotherms over Europe have a meridional orientation.

The fact that Eurasia and North America face the Arctic basin as a broad front contributes to the deep penetration of cold air masses onto the continents throughout the year. Intense meridional transport of air masses is especially characteristic of North America, where arctic and tropical air often replace each other.

Tropical air entering the plains of North America with southern cyclones is also slowly transformed due to the high speed of its movement, high moisture content and continuous low clouds.

In winter, the consequence of intense meridional circulation of air masses is the so-called “jumps” of temperatures, their large inter-day amplitude, especially in areas where cyclones are frequent: in northern Europe and Western Siberia, Great Plains of North America.

During the cold period, they fall in the form of snow, a snow cover is formed, which protects the soil from deep freezing and creates a supply of moisture in the spring. The depth of the snow cover depends on the duration of its occurrence and the amount of precipitation. In Europe, stable snow cover on flat areas forms east of Warsaw, its maximum height reaches 90 cm in the northeastern regions of Europe and Western Siberia. In the center of the Russian Plain, the height of snow cover is 30-35 cm, and in Transbaikalia - less than 20 cm. On the plains of Mongolia, in the center of the anticyclonic region, snow cover forms only in some years. The lack of snow, along with low winter air temperatures, causes the presence of permafrost, which is not observed anywhere else on the globe at these latitudes.

In North America, snow cover is negligible on the Great Plains. To the east of the plains, tropical air increasingly begins to take part in frontal processes; it aggravates frontal processes, which causes heavy snowfalls. In the Montreal area, snow cover lasts up to four months, and its height reaches 90 cm.

Summer in the continental regions of Eurasia is warm. The average July temperature is 18-22 °C. In the arid regions of southeastern Europe and Central Asia, the average air temperature in July reaches 24-28 °C.

In North America, continental air in summer is somewhat colder than in Asia and Europe. This is due to the smaller latitudinal extent of the continent, the large ruggedness of its northern part with bays and fjords, the abundance of large lakes, and the more intense development of cyclonic activity compared to the interior regions of Eurasia.

In the temperate zone, the annual precipitation on the flat continental areas varies from 300 to 800 mm; on the windward slopes of the Alps more than 2000 mm falls. Most of the precipitation falls in summer, which is primarily due to an increase in the moisture content of the air. In Eurasia, there is a decrease in precipitation across the territory from west to east. In addition, the amount of precipitation decreases from north to south due to a decrease in the frequency of cyclones and an increase in dry air in this direction. In North America, a decrease in precipitation across the territory is observed, on the contrary, towards the west. Why do you think?

Most of the land in the continental temperate climate zone is occupied by mountain systems. These are the Alps, Carpathians, Altai, Sayans, Cordillera, Rocky Mountains, etc. In mountainous areas climatic conditions differ significantly from the climate of the plains. In summer, the air temperature in the mountains drops quickly with altitude. In winter, when cold air masses invade, the air temperature on the plains is often lower than in the mountains.

The influence of mountains on precipitation is great. Precipitation increases on windward slopes and at some distance in front of them, and decreases on leeward slopes. For example, differences in annual precipitation between the western and eastern slopes of the Ural Mountains in some places reach 300 mm. In mountains, precipitation increases with altitude to a certain critical level. In the Alps the level the largest number precipitation occurs at altitudes of about 2000 m, in the Caucasus - 2500 m.

Subtropical climate zone

Continental subtropical climate determined by the seasonal change of temperate and tropical air. The average temperature of the coldest month in Central Asia is below zero in some places, in the northeast of China -5...-10°C. The average temperature of the warmest month ranges from 25-30 °C, with daily maximums exceeding 40-45 °C.

The most strongly continental climate in the air temperature regime is manifested in the southern regions of Mongolia and northern China, where the center of the Asian anticyclone is located in the winter season. Here the annual air temperature range is 35-40 °C.

Sharply continental climate in the subtropical zone for the high mountain regions of the Pamirs and Tibet, the altitude of which is 3.5-4 km. The climate of the Pamirs and Tibet is characterized by cold winters, cool summers and low rainfall.

In North America, the continental arid subtropical climate is formed in closed plateaus and in intermountain basins located between the Coast and Rocky Ranges. Summers are hot and dry, especially in the south, where the average July temperature is above 30 °C. The absolute maximum temperature can reach 50 °C and above. A temperature of +56.7 °C was recorded in Death Valley!

Humid subtropical climate characteristic of the eastern coasts of continents north and south of the tropics. The main areas of distribution are the southeastern United States, some southeastern parts of Europe, northern India and Myanmar, eastern China and southern Japan, northeastern Argentina, Uruguay and southern Brazil, the coast of Natal in South Africa and the eastern coast of Australia. Summer in the humid subtropics is long and hot, with temperatures similar to those in the tropics. The average temperature of the warmest month exceeds +27 °C, and the maximum is +38 °C. Winters are mild, with average monthly temperatures above 0 °C, but occasional frosts have a detrimental effect on vegetable and citrus plantations. In the humid subtropics, average annual precipitation amounts range from 750 to 2000 mm, and the distribution of precipitation across seasons is quite uniform. In winter, rain and rare snowfalls are brought mainly by cyclones. In summer, precipitation falls mainly in the form of thunderstorms associated with powerful inflows of warm and humid oceanic air, characteristic of the monsoon circulation of East Asia. Hurricanes (or typhoons) occur in late summer and fall, especially in the Northern Hemisphere.

Subtropical climate with dry summers, typical for the western coasts of continents north and south of the tropics. In Southern Europe and North Africa Such climatic conditions are typical for the coasts of the Mediterranean Sea, which is the reason for calling this climate also Mediterranean. The climate is similar in southern California, central Chile, extreme southern Africa and parts of southern Australia. All these areas have hot summers and mild winters. As in the humid subtropics, there are occasional frosts in winter. In inland areas, summer temperatures are significantly higher than on the coasts, and often the same as in tropical deserts. In general, clear weather prevails. In summer, there are often fogs on the coasts near which ocean currents pass. For example, in San Francisco, summers are cool and foggy, and the warmest month is September. The maximum precipitation is associated with the passage of cyclones in winter, when the prevailing air currents mix towards the equator. The influence of anticyclones and downdrafts of air over the oceans cause the dry summer season. The average annual precipitation in a subtropical climate ranges from 380 to 900 mm and reaches maximum values ​​on the coasts and mountain slopes. In summer there is usually not enough rainfall for normal tree growth, and therefore a specific type of evergreen shrubby vegetation develops there, known as maquis, chaparral, mali, macchia and fynbos.

Equatorial climate zone

Equatorial climate type distributed in equatorial latitudes in the Amazon basin in South America and the Congo in Africa, on the Malacca Peninsula and on the islands of Southeast Asia. Usually average annual temperature about +26 °C. Due to the high midday position of the Sun above the horizon and the same length of day throughout the year, seasonal temperature fluctuations are small. Humid air, cloudiness and dense vegetation cover prevent night cooling and maintain maximum temperatures. daytime temperatures below +37 °C, lower than in higher latitudes. The average annual precipitation in the humid tropics ranges from 1500 to 3000 mm and is usually evenly distributed over the seasons. Precipitation is mainly associated with the Intertropical Convergence Zone, which is located slightly north of the equator. Seasonal shifts of this zone to the north and south in some areas lead to the formation of two maximum precipitation during the year, separated by drier periods. Every day, thousands of thunderstorms roll over the humid tropics. In between, the sun shines in full force.

The Earth's climate has a large number of patterns and is formed under the influence of many factors. At the same time, it is fair to include a variety of phenomena in the atmosphere. The climatic state of our planet largely determines the state of the natural environment and human activities, especially economic ones.

The Earth's climatic conditions are formed by three large-scale geophysical processes of a cyclic type:

• Heat turnover- exchange of heat between the earth's surface and the atmosphere.
• Moisture circulation- the intensity of water evaporation into the atmosphere and its correlation with the level of precipitation.
• General atmospheric circulation- a set of air currents over the Earth. The state of the troposphere is determined by the characteristics of the distribution of air masses, for which cyclones and anticyclones are responsible. Atmospheric circulation occurs due to the unequal distribution of atmospheric pressure, which is caused by the division of the planet into land and water bodies, as well as uneven access to ultraviolet light. The intensity of sunlight is determined not only by geographical features, but also by the proximity of the ocean and the frequency of precipitation.

Climate should be distinguished from weather, which represents the state of the environment at the current moment. However, weather characteristics are often the object of study of climatology or even the most important factors in changing the Earth's climate. In development earth's climate, as well as weather conditions, the heat level plays a special role. The climate is also influenced by sea currents and terrain features, in particular the proximity of mountain ranges. An equally important role belongs to the prevailing winds: warm or cold.

In the study of the Earth's climate, careful attention is paid to such meteorological phenomena like atmospheric pressure, relative humidity, wind parameters, temperature indicators, precipitation. They also try to take solar radiation into account when compiling a general planetary picture.

Climate-forming factors

1. Astronomical factors: the brightness of the Sun, the relationship between the Sun and the Earth, features of orbits, the density of matter in space. These factors influence the level of solar radiation on our planet, daily weather changes, and the spread of heat between the hemispheres.
2. Geographical factors: the weight and parameters of the Earth, gravity, air components, atmospheric mass, ocean currents, the nature of the earth's topography, sea level, etc. These features determine the level of heat received in accordance with the weather season, continent and hemisphere of the earth.

The Industrial Revolution led to the inclusion of active human activity in the list of climate-forming factors. However, all characteristics of the Earth's climate are largely influenced by the energy of the Sun and the angle of incidence of ultraviolet rays.

Types of Earth's climate

There are many classifications of the planet's climate zones. Various researchers take the separation as a basis, both individual characteristics and the general circulation of the atmosphere or the geographical component. Most often, the basis for identifying a separate type of climate is the solar climate - the influx of solar radiation. The proximity of bodies of water and the relationship between land and sea are also important.

The simplest classification identifies 4 basic zones in each earth’s hemisphere:

• equatorial;
• tropical;
• moderate;
• polar.

There are transitional areas between the main zones. They have the same names, but with the prefix “sub”. The first two climates, together with the transitions, can be called hot. In the equatorial region there is a lot of precipitation. Temperate climates have more pronounced seasonal differences, especially in the case of temperature. As for the cold climate zone, then these are the most severe conditions caused by the lack of solar heat and water vapor.

This division takes into account atmospheric circulation. Based on the predominance of air masses, it is easier to divide the climate into oceanic, continental, and also the climate of the eastern or western coasts. Some researchers additionally define continental, maritime and monsoon climates. Often in climatology there are descriptions of mountainous, arid, nival and humid climates.

Ozone layer

This concept refers to a layer of the stratosphere with elevated levels of ozone, which is formed due to the influence of sunlight on molecular oxygen. Thanks to the absorption of ultraviolet radiation by atmospheric ozone, the living world is protected from combustion and widespread cancer. Without the ozone layer, which appeared 500 million years ago, the first organisms would not have been able to emerge from the water.

Since the second half of the 20th century, it has been customary to talk about the problem of the “ozone hole” - a local decrease in ozone concentration in the atmosphere. The main factor of this change is anthropogenic in nature. The ozone hole can lead to increased mortality of living organisms.

Global climate changes on Earth

(Increase in average air temperature over the last century, starting in the 1900s)

Some scientists view large-scale climate transformations as a natural process. Others believe that this is a harbinger of a global catastrophe. Such changes mean a strong warming of air masses, an increase in the level of aridity and a softening of winters. We are also talking about frequent hurricanes, typhoons, floods and droughts. The cause of climate change is the instability of the Sun, which leads to magnetic storms. Changes in the earth's orbit, the outlines of oceans and continents, and volcanic eruptions also play a role. The greenhouse effect is also often associated with destructive human activities, namely: air pollution, destruction of forests, plowing of land, and burning of fuel.

Global warming

(Climate change towards warming in the second half of the 20th century)

An increase in the average temperature of the Earth has been recorded since the second half of the 20th century. Scientists believe that the reason for this is high level greenhouse gases due to human activity. The consequences of rising global temperatures include changes in precipitation, the growth of deserts, an increase in extreme weather events, the extinction of some species, and rising sea levels. The worst thing is that in the Arctic this leads to shrinking glaciers. All together this can radically change the habitat of different animals and plants, shift boundaries natural areas and cause serious problems to agriculture and human immunity.