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Global climate change causes briefly. Factors affecting the climate. Manifestations of climate change

Changing of the climate- fluctuations in the climate of the Earth as a whole or its individual regions over time, expressed in statistically significant deviations of weather parameters from long-term values ​​over a period of time from decades to millions of years. Changes in both mean values ​​of weather parameters and changes in the frequency of extreme weather events are taken into account. The study of climate change is the science of paleoclimatology. The cause of climate change is dynamic processes on the Earth, external influences such as fluctuations in the intensity of solar radiation, and, more recently, human activities. Changes in the modern climate (in the direction of warming) are called global warming.

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Manifestations of climate change

Weather is the state of the lower layers of the atmosphere at a given time, in a given place. The weather is a chaotic non-linear dynamic system. Climate is the average state of the weather and is predictable. Climate includes such variables as average temperature, rainfall, number of sunny days, and other variables that can be measured in a particular place. However, there are also processes on Earth that can affect the climate.

glaciation

  • change in size, topography and relative position of continents and oceans,
  • change in the luminosity of the Sun,
  • changes in the parameters of the Earth's orbit and axis,
  • changes in the transparency and composition of the atmosphere, including changes in the concentration of greenhouse gases (CO 2 and CH 4),
  • change in the reflectivity of the Earth's surface (albedo),
  • change in the amount of heat available in the depths of the ocean, [ ]

Non-anthropogenic factors and their impact on climate change

Plate tectonics

Over long periods of time, tectonic movements plates move continents, form oceans, create and destroy mountain ranges, that is, create a surface on which there is a climate. Recent studies show that tectonic movements exacerbated the conditions of the last ice age: about 3 million years ago, the North and South American plates collided, forming the Isthmus of Panama and blocking the direct mixing of the waters of the Atlantic and Pacific Oceans.

solar radiation

On shorter time intervals, changes in solar activity are also observed: an 11-year solar cycle and longer secular and millennial modulations. However, the 11-year cycle of sunspot occurrence and disappearance is not tracked explicitly in the climatological data. Changes in solar activity are considered an important factor in the onset of the Little Ice Age, as well as some of the warming observed between 1900 and 1950. The cyclical nature of solar activity is not yet fully understood; it differs from those slow changes that accompany the development and aging of the Sun.

Milankovitch cycles

In the course of its history, the planet Earth regularly changes the eccentricity of its orbit, as well as the direction and angle of its axis, which leads to a redistribution of solar radiation on the Earth's surface. These changes are called "Milankovitch cycles", they are predictable with high accuracy. There are 4 Milankovitch cycles:

  1. Precession- rotation of the earth's axis under the influence of the attraction of the moon, as well as (to a lesser extent) the sun. As Newton found out in his "Principles", the oblateness of the Earth at the poles leads to the fact that the attraction of external bodies turns the earth's axis, which describes a cone with a period (according to modern data) of approximately 25,776 years, as a result of which the seasonal amplitude of the intensity of the solar flux changes by northern and southern hemispheres of the Earth;
  2. Nutation- long-term (so-called secular) fluctuations in the angle of inclination of the earth's axis to the plane of its orbit with a period of about 41,000 years;
  3. Long-term fluctuations in the eccentricity of the Earth's orbit with a period of about 93,000 years;
  4. Movement of the perihelion of the Earth's orbit and the ascending node of the orbit with a period of 10 and 26 thousand years, respectively.

Since the described effects are periodic with a non-multiple period, sufficiently long epochs regularly occur when they have a cumulative effect, reinforcing each other. They are considered the main reasons for the alternation of glacial and interglacial cycles of the last ice age, including explaining the Climatic Optimum of the Holocene. The precession of the earth's orbit also results in smaller changes, such as the periodic increase and decrease in the area of ​​the Sahara Desert.

Volcanism

One strong volcanic eruption can affect the climate, causing a cooling spell lasting several years. For example, the eruption of Mount Pinatubo in 1991 significantly affected the climate. The giant eruptions that form the largest igneous provinces occur only a few times every hundred million years, but they affect the climate for millions of years and cause the extinction of species. Initially, it was assumed that the cause of the cooling was volcanic dust thrown into the atmosphere, since it prevents solar radiation from reaching the Earth's surface. However, measurements show that most of the dust settles on the Earth's surface within six months.

Volcanoes are also part of the geochemical carbon cycle. Over many geological periods, carbon dioxide has been released from the Earth's interior into the atmosphere, thereby neutralizing the amount of CO 2 removed from the atmosphere and bound by sedimentary rocks and other geological sinks of CO 2 . However, this contribution is not comparable in magnitude to the anthropogenic emission of carbon monoxide, which, according to the US Geological Survey, is 130 times greater than the amount of CO 2 emitted by volcanoes.

Anthropogenic impact on climate change

Anthropogenic factors include human activities that change the environment and affect the climate. In some cases the causal relationship is direct and unambiguous, such as in the effect of irrigation on temperature and humidity, in other cases the relationship is less clear. Various hypotheses of human influence on climate have been discussed over the years. In the late 19th century, in the western United States and Australia, for example, the "rain follows the plow" theory was popular.

The main problems today are: the increasing concentration of CO 2 in the atmosphere due to fuel combustion, aerosols in the atmosphere that affect its cooling, and the cement industry. Other factors such as land use, depletion of the ozone layer, livestock and deforestation also affect the climate.

Interaction of factors

The impact on the climate of all factors, both natural and anthropogenic, is expressed by a single value - radiative heating of the atmosphere in W/m 2 . [ ] Volcanic eruptions, glaciations, continental drift and the shift of the Earth's poles are powerful natural processes that affect the Earth's climate. On a scale of several years, volcanoes may play a major role. As a result of the 1991 eruption of the Pinatubo volcano in the Philippines, so much ash was thrown to a height of 35 km that the average level of solar radiation decreased by 2.5 W / m 2. However, these changes are not long-term, particles settle down relatively quickly. On a millennium scale, the climate-determining process is likely to be the slow movement from one ice age to the next.

On a scale of several centuries, in 2005 compared to 1750 there is a combination of multidirectional factors, each of which is much weaker than the result of an increase in the concentration of greenhouse gases in the atmosphere, estimated as a warming of 2.4-3.0 W/m 2 . The human influence is less than 1% of the total radiation balance, and the anthropogenic increase in the natural greenhouse effect is approximately 2%, from 33 to 33.7 degrees C. Thus, the average air temperature near the Earth's surface has increased since the pre-industrial era (since about 1750) by 0.7 °С

The cycle of climate change

35-45 year cycles of climate change

The alternation of cool-wet and warm-dry periods in the interval of 35-45 years, put forward at the end of the 19th century. Russian scientists E. A. Brikner and A. I. Voeikov. Subsequently, these scientific principles were substantially developed by A.V. Shnitnikov in the form of a coherent theory of intra- and multi-century climate variability and the general moisture content of the continents of the Northern Hemisphere. The system of evidence is based on facts about the nature of changes in the mountain glaciation of Eurasia and North America, the levels of filling of inland water bodies, including the Caspian Sea, the level of the World Ocean, the variability of the ice situation in the Arctic, and historical information about the climate. .

- this is established during the XX-XXI centuries. direct instrumental observations of global and regional climate warming under the influence of natural and anthropogenic factors.

There are two points of view that determine the main causes of global warming.

According to the first point of view , post-industrial warming (an increase in the average global temperature over the past 150 years by 0.5-0.7 °C) is a natural process and is comparable in amplitude and speed to those parameters of temperature fluctuations that took place in certain intervals of the Holocene and Late Glacial. It is argued that temperature fluctuations and variations in the concentration of greenhouse gases in the modern climatic epoch do not exceed the amplitude of variability in the values ​​of climatic parameters that have taken place in the history of the Earth over the past 400 thousand years.

Second point of view adhere to most researchers who explain global warming by anthropogenic accumulation of greenhouse gases in the atmosphere - carbon dioxide CO 2, methane CH 4, nitrous oxide N 2 O, ozone, freons, tropospheric ozone O 3, as well as some other gases and water vapor. Contribution to the greenhouse effect (in%) of carbon dioxide - 66%, methane - 18, freons - 8, oxide - 3, other gases - 5%. According to the data, concentrations of greenhouse gases in the air have increased since pre-industrial times (1750): CO 2 from 280 to almost 360 ppmv, CH 4 from 700 to 1720 ppmv, and N 2 O from about 275 to almost 310 ppmv. The main source of CO 2 are industrial emissions. At the end of the XX century. humanity burned annually 4.5 billion tons of coal, 3.2 billion tons of oil and oil products, as well as natural gas, peat, oil shale and firewood. All this turned into carbon dioxide, the content of which in the atmosphere increased from 0.031% in 1956 to 0.035% in 1992 and continues to grow.

Emissions into the atmosphere of another greenhouse gas, methane, also increased sharply. Methane until the beginning of the XVIII century. had concentrations close to 0.7 ppmv, but over the past 300 years, its first slow and then accelerating growth has been observed. Today, the growth rate of CO 2 concentration is 1.5-1.8 ppmv/year, and CH 4 concentration is 1.72 ppmv/year. The rate of increase in the concentration of N 2 O - an average of 0.75 ppmv / year (for the period 1980-1990). A sharp warming of the global climate began in the last quarter of the 20th century, which in the boreal regions was reflected in a decrease in the number of frosty winters. The average temperature of the surface layer of air over the past 25 years has increased by 0.7 °C. In the equatorial zone, it has not changed, but the closer to the poles, the more noticeable the warming. The temperature of the under-ice water in the region of the North Pole increased by almost 2 °C, as a result of which the ice began to melt from below. Over the past hundred years, the global average temperature has risen by almost one degree Celsius. However, the bulk of this warming took place before the end of the 1930s. Then, from about 1940 to 1975, there was a decrease of about 0.2°C. Since 1975, the temperature began to rise again (the maximum increase was in 1998 and 2000). Global climate warming is manifested in the Arctic 2-3 times stronger than in the rest of the planet. If current trends continue, then in 20 years, due to the decrease in ice cover, Hudson Bay may become unsuitable for polar bears. And by the middle of the century, navigation along the Northern Sea Route may increase to 100 days a year. Now it lasts about 20 days. Studies of the main features of the climate over the past 10-15 years have shown that this period is the warmest and wettest not only in the last 100 years, but also in the last 1000 years.

The factors that really determine global climate change are:

  • solar radiation;
  • orbital parameters of the Earth;
  • tectonic movements that change the ratio of the areas of the water surface of the Earth and land;
  • the gas composition of the atmosphere and, above all, the concentration of greenhouse gases - carbon dioxide and methane;
  • transparency of the atmosphere, which changes the Earth's albedo due to volcanic eruptions;
  • technogenic processes, etc.

Forecasts of global climate change in the 21st century. show the following.

Air temperature. According to the ensemble of predictive models of the IPCC (Intergovernmental Panel on Climate Change), the average global warming will be 1.3 °C by the middle of the 21st century. (2041-2060) and 2.1 °C towards its end (2080-2099). On the territory of Russia in different seasons, the temperature will change within a fairly wide range. Against the background of general global warming, the largest increase in surface temperature in the XXI century. will be winter in Siberia and the Far East. The temperature increase along the coast of the Arctic Ocean will be 4 °C in the middle of the 21st century. and 7-8 °C at its end.

Precipitation. According to the ensemble of IPCC AOGCM models, the average estimates of the global increase in average annual precipitation are 1.8% and 2.9%, respectively, for the middle and end of the 21st century. The average annual increase in precipitation throughout Russia will significantly exceed these global changes. In many Russian watersheds, precipitation will increase not only in winter, but also in summer. In the warm season, the increase in precipitation will be noticeably less and will be observed mainly in the northern regions, in Siberia and the Far East. In summer, predominantly convective precipitation will intensify, which indicates the possibility of an increase in the frequency of showers and associated extreme weather patterns. In summer, in the southern regions of the European territory of Russia and in Ukraine, the amount of precipitation will decrease. In winter, the proportion of liquid precipitation will increase in the European part of Russia and its southern regions, while the amount of solid precipitation will increase in Eastern Siberia and Chukotka. As a result, the mass of snow accumulated during the winter in western and southern Russia will decrease and, accordingly, additional snow accumulation in central and eastern Siberia will decrease. At the same time, for the number of days with precipitation, their variability will increase in the 21st century. compared to the 20th century. The contribution of the heaviest precipitation will increase significantly.

Soil water balance. With climate warming, together with an increase in precipitation in the warm season, evaporation from the land surface will increase, which will lead to a noticeable decrease in the moisture content of the active soil layer and runoff throughout the territory under consideration. Based on the difference in precipitation and evaporation calculated for the current climate and the climate of the 21st century, it is possible to determine the total change in the moisture content of the soil layer and runoff, which, as a rule, have the same sign (i.e., with a decrease in soil moisture, a decrease in the total drain and vice versa). In regions free from snow cover, the trend towards a decrease in soil moisture content will be revealed already in spring and will become more noticeable throughout Russia.

River runoff. An increase in annual precipitation under global climate warming will lead to a noticeable increase in river runoff in most watersheds, with the exception of only the watersheds of the southern rivers (Dnepr - Don), where the annual runoff by the end of the 21st century will increase. will decrease by about 6%.

The groundwater. With global warming at the GS (at the beginning of the 21st century), there will be no significant changes in the supply of groundwater compared to modern conditions. In most of the country, they will not exceed ± 5-10%, and only in a part of the territory of Eastern Siberia they can reach + 20-30% of the current norm of groundwater resources. However, already by this period, there will be a trend towards an increase in groundwater runoff in the north and its decrease in the south and southwest, which is in good agreement with modern trends noted by long series of observations.

Cryolithozone. According to forecasts made using five different climate change models, in the next 25-30 years, the area of ​​"permafrost" may decrease by 10-18%, and by the middle of the century by 15-30%, while its border will shift to the northeast at 150-200 km. The depth of seasonal thawing will increase everywhere, on average by 15-25%, and on the Arctic coast and in certain areas of Western Siberia up to 50%. In Western Siberia (Yamal, Gydan), the temperature of frozen soils will increase by an average of 1.5-2 °C, from -6 ... -5 °С to -4 ... -3 °С, and there will be a danger of formation of high-temperature frozen soils even in areas Arctic. In the areas of permafrost degradation in the southern peripheral zone, the permafrost islands will thaw. Since the frozen strata here have a small thickness (from a few meters to several tens of meters), complete thawing of most permafrost islands is possible over a period of about several decades. In the coldest northern zone, where "permafrost" underlies more than 90% of the surface, the depth of seasonal thawing will mainly increase. Large islands of non-through thawing can also appear and develop here, mainly under water bodies, with the permafrost roof detached from the surface and preserved in deeper layers. The intermediate zone will be characterized by discontinuous distribution of frozen rocks, the density of which will decrease in the process of warming, and the depth of seasonal thawing will increase.

Global changes in the Earth's climate will have a significant impact on the main sectors of the economy.

Agriculture. Climate change will reduce potential yields in most tropical and subtropical regions. If global mean temperature rises by more than a few degrees, yields will decrease in mid-latitudes (which cannot be compensated for by changes in high latitudes). Drylands will be the first to suffer. The increase in CO 2 concentration can potentially be a positive factor, but most likely will be more than “compensated” by secondary negative effects, especially where agriculture is carried out with extensive methods.

Forestry. The expected climate changes for a period of 30-40 years lie within the range of acceptable changes in the conditions for the growth of tree flora in natural forests. However, the expected climatic changes may disrupt the established course of relationships between tree species at the stage of natural regeneration of forests after cuttings, fires, in the centers of diseases and pests. The indirect impact of climate change on tree species, especially young stands, is an increase in the frequency of short-term extreme weather conditions (heavy snowfalls, hail, storms, droughts, late spring frosts, etc.). Global warming will cause an increase in the growth rate of softwood stands of about 0.5-0.6% per year.

Water supply. In any case, unfavorable trends in water supply will cover a relatively small part of the territory of Russia, but in the greater part of it, the possibilities for water supply of any type of economic activity will improve due to a harmless increase in water withdrawal from groundwater bodies and all large rivers.

Human health and vital activity. The health and quality of life of most Russians should improve. The comfort of the climate will increase and the area of ​​the favorable living area will increase. The labor potential will increase, positive changes in working conditions in the northern regions will be especially noticeable. Global warming, together with the rationalization of the Arctic development strategy, will lead to an increase in the average life expectancy there by about one year. The greatest direct impact of heat stress will be felt in cities, where the most vulnerable (old people, children, people suffering from heart disease, etc.) and low-income groups of the population will be in the worst situation.

Sources: Assessments of global and regional climate changes in the 19th-21st centuries based on the IAP RAS model, taking into account anthropogenic impacts. Anisimov O.A. and others. Izv. RAN, 2002, FAO, 3, no. 5; Kovalevsky V.S., Kovalevsky Yu.V., Semenov S.M. Impact of climate change on groundwater and interconnected environment // Geoecology, 1997, no. 5; Upcoming Climate Changes, 1991.

The changing climate has a huge impact on both natural and socio-economic processes. In recent years, the Intergovernmental Committee on Climate Change has analyzed six alternative scenarios for changing the lives of the population, economy and energy as a result of global temperature increase during the 21st century.

The focus of these studies was on the sensitivity, adaptability and vulnerability of natural and socio-economic systems. Sensitivity is the ability of a system to respond to changes in climatic conditions. A convincing example is the indicator of changes in the structure and functioning of an ecosystem of any rank and the primary production produced by it, depending on a given change or fluctuation in the temperature of the surface part, humidity and the amount of precipitation. Adaptability depends on the possibilities inherent in the system to change the mode of operation, the speed and direction of the processes occurring in it, and the possibilities of structuring that arise in this case from the upcoming climatic changes. Vulnerability determines the degree of damage to the system.

As a result of changes in global climatic indicators - average annual temperatures and humidity - corresponding changes in land landscapes will occur, denudation and weathering rates will increase or decrease, the landscapes of the World Ocean will change, shelves will expand or narrow, and significant changes will occur in the field of agriculture.

Landscape Changes

In mid-latitudes, a temperature increase of 1-3.5°C, which is predicted for the next century, is equivalent to a shift of isotherms by 150-550 km in latitude towards the poles and by 150-550 m in height. In accordance with this, the movement of plant ecosystems will begin. However, due to its certain inertia, the movement of fauna and flora will lag behind the changes in the climate in which they developed, and then they will have to exist for some time in an unusual climatic regime. It is assumed that the rate of climate change will be higher than the ability of some species, except for individual animal communities, to migrate to places favorable for life. As a result of the displacement of climatic regions and zones, some types of forest cover may disappear. Plant ecosystems will not move along with climatic conditions as an integral part of them. Separate components of plant biocenoses will move at different speeds. Because of this uneven and selective process, new combinations and associations of species and communities may emerge that will create previously unknown ecosystems. Temperate forests will lose some of their species with a concomitant increase in carbon dioxide emissions from the oxidation of dying biomass.

It is assumed that a third or half of the mountain glaciers will melt. There is no consensus regarding the ice sheets and Greenland. Some scientists believe that in the next hundred years their area, and possibly their volume, will not change, while others, on the contrary, predict a significant reduction.

Desert landscapes will turn out to be more arid due to a significant increase in air temperature compared to precipitation. At the same time, there are calculations showing that there will be a migration of desert areas towards the poles, and the size of modern deserts will decrease.

Changes in the area of ​​the World Ocean

First of all, an increase in temperatures will lead to some sea level rise and a change in the surface and deep circulation of ocean waters, which will affect the distribution and volume of nutrients, including carbon, and will affect biological productivity. The increased volume of ocean waters and high temperatures will contribute to the accumulation of carbonates, which will lead to a greater removal of carbon dioxide from the atmosphere.

The change in the ocean level primarily depends on hydrometeorological factors that directly affect evaporation and precipitation, as well as on the additional inflow of water arising from the melting of ice sheet and mountain glaciers, and the runoff of water from continental spaces. In addition to hydrometeorological factors, the level of the World Ocean is influenced by the tectonic factor that determines the shape and volume of the bed of the World Ocean, and exogenous factors, in particular geomorphological processes, which include the accumulation of sediments in river mouths, estuaries, estuaries and bays or coastal erosion. The rise in sea level up to 25 cm observed over the past century is the result of the combined effect of all three factors, with the leading role of hydrometeorological ones.

More than half of humanity will suffer from changes in the level of the World Ocean. Therefore, to the existing problems, climate change will add new ones, which will have a very significant impact on coastal areas. These problems are related to the high and ever-increasing anthropogenic pressure on coastal systems, many of which are currently at particular risk. Mangrove systems, which are saline coastal swamps, coral reefs and atolls, as well as river delta and estuary systems, are particularly in distress.

An increase in the level, with a concomitant increase in the frequency and strength of storm surges caused by intensification of tropical cyclones, will lead to flooding of low-lying coastal areas, destruction of coasts and coastal structures, change in the rate and volume of accumulation, and change the conditions for the transport of detrital material and dissolved substances. All this can lead to unpredictable consequences. According to forecast estimates, low-lying islands and flat coasts, on which many large cities and urban agglomerations are located, will be the first to suffer. At the same time, it should be taken into account that in the event of large-scale floods, significant migrations of the population with serious socio-economic and political consequences are likely.

Water resources

Climate change will intensify the global hydrological cycle and cause marked regional changes. Relatively small climate changes can cause non-linear changes in evapotranspiration and soil moisture, resulting in relatively small runoff modifications, especially in arid areas. In some cases, with an increase in the average annual temperature by 1-2°C and a decrease in the total amount of precipitation by 10%, the average annual runoff will decrease by about 40-70%. This will require significant capital investments to adapt the water sector to the changed conditions. Especially big problems will arise in those regions where water consumption is significant, and in regions with severe water pollution.

Agriculture

Climate change will have a major impact on agricultural systems. This will force us to take urgent measures to adapt agriculture to new conditions.

Climate impacts on agricultural systems will be very complex and ambiguous. Due to the increase in the concentration of carbon dioxide, the volume and rate of photosynthesis will increase and, as a consequence, the yield. The harvest of agricultural crops will also increase due to the involvement of new lands in the agricultural turnover. In areas where farming is limited by the influx of warm air, such as Russia and Canada, the likelihood of increased yields will increase. In arid and semi-arid regions, where it is limited by the availability of sufficient moisture for plants, climate change will be adversely affected. Needs for irrigation will compete strongly with other consumers of water resources - industry and utilities. Higher air temperatures will accelerate the natural decomposition of soil organic matter, reducing its fertility. The likelihood of the spread of pests and plant diseases will increase.

In general, it is predicted that the global level of agricultural production can be maintained at the current level, but the regional impacts will vary widely. The overall picture of world trade in agricultural products due to global climate change may change significantly.

Expected climate changes are also associated with significant changes in human health, the work of the hydropower industry, mainly water, transport, forestry, metallurgical, machine-building, mining and other industries.

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, a sharp warming began to be observed. The number of winters with very low temperatures has significantly decreased, 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 should be borne in mind that global climate change can lead to dangerous consequences for all mankind. 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. Changing dynamic processes on the Earth, the influence of external influences, solar radiation on the planet has led to climate change.

We know from school that the climate on our planet is divided into several types. Namely, there are four climatic zones:

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

Each type has specific value parameters:

  • Temperatures.
  • The amount of precipitation in winter and summer.

It is also known that the climate significantly affects the vital activity of plants and animals, as well as the soil and water regime. It depends on what kind of climate prevails in a given region, which crops can be grown in the fields and in subsidiary farms. The resettlement 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. Consider how the climate can change.

Manifestations of a changing climate

Global climate change manifests itself 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 are outside the normal range, but are considered extreme.

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


It is worth noting that climate change on the planet is currently happening very quickly. Thus, the planetary temperature has risen by half a degree in only some half a century.

What factors influence the climate

Based on the processes listed above, which indicate climate change, several factors can be identified that affect these processes:

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

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

Causes that provoke a change in climatic conditions

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 the young cold it slowly passes into the aging stage. Solar activity was one of the causes of 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 the Earth's Orbit leads to a change, redistribution of solar radiation on the surface. Our planet is affected by the attraction of the moon and other planets.

4. The impact of volcanoes. It is as follows:

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

Passively degassing volcanoes have a global impact on the atmosphere, as does 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 global warming. This is an increase in greenhouse gases that are emitted and accumulate in the atmosphere. As a result, the ability of terrestrial and oceanic ecosystems to absorb carbon dioxide as it grows in the atmosphere decreases.

Human activities affecting global climate change:


Scientists, based on their research, concluded that if natural causes influenced the climate, the temperature on earth would be lower. It is human influence that contributes to the increase in temperature, 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 positive aspects of global warming.

Seeking benefits in a changing climate

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

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

Global impacts of climate change

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


Earth's climate change will have a significant impact on human health. The number of cardiovascular and other diseases may increase.

  • A decrease in food production can lead to starvation, especially for the poor.
  • The problem of global climate change, of course, will also affect the political issue. Possible intensification of conflicts over the right to own sources of fresh water.

At present, we can already observe some of the effects of climate change. How will the climate on our planet continue to change?

Predictions 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 the rise in temperature, will not be abrupt. There is a mobile atmosphere on Earth, thermal energy is distributed throughout the planet due to the movement of air masses. The oceans store more heat than the atmosphere. On such a large planet with its complex system, change cannot happen too quickly. It will take millennia for significant change.
  2. Rapid global warming. This scenario is much more common. The temperature has increased over the last century by half a degree, 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 rise significantly. The number of cataclysms on the planet will increase. The amount of precipitation on Earth will be unevenly distributed, which will increase the areas affected by drought.
  3. In some parts of the Earth, warming will be replaced by a short-term cooling. Scientists have calculated such a scenario, based on the fact that the warm Gulf Stream has become 30% slower and can completely stop if the temperature rises by 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 possible only for a short period of time, and then warming will return to Europe. And everything will develop according to 2 scenarios.
  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 pass into the atmosphere. The carbonate sedimentary rocks will decompose with even more carbon dioxide, which will lead to an even greater increase in temperature and the decomposition of carbonate rocks in deeper layers. Glaciers will melt rapidly, while 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 of the Earth, as we see, can be a danger to all mankind. 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 cannot fail to affect all regions of the country. It will reflect both positively and negatively. The residential zone will move closer to the north. Heating costs will be significantly reduced, and the transportation of goods along the Arctic coast on large rivers will be simplified. In the northern regions, the melting of snow in areas where there was permafrost can lead to serious damage to communications and buildings. Migration will begin. Already in recent years, the number of such phenomena as drought, storm winds, heat, floods, severe 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 cannot 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 the issues of global climate change.

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

As a result of studying the materials of meteorological observations carried out in all regions of the globe, it has been established that the climate is not constant, but is subject to certain changes. Started at the end of the 19th century. warming especially intensified in the 1920s and 30s, but then a slow cooling began, which stopped in the 1960s. Studies by geologists of sedimentary deposits of the earth's crust have shown that much greater climate changes have occurred in past epochs. Since these changes were due to natural processes, they are called natural.

Along with natural factors, global climate conditions are increasingly influenced by human economic activity. This influence began to manifest itself thousands of years ago, when, in connection with the development of agriculture in arid regions, artificial irrigation began to be widely used. The spread of agriculture in the forest zone also led to some climate changes, as it required deforestation over large areas. However, climate change was mainly limited to changes in meteorological conditions only in the lower air layer in those areas where significant economic activities were carried out.

In the second half of the XX century. In connection with the rapid development of industry and the growth of energy availability, climate change threats have arisen throughout the planet. Modern scientific research has established that the impact of anthropogenic activity on the global climate is associated with the action of several factors, of which the most important are:

  • an increase in the amount of atmospheric carbon dioxide, as well as some other gases entering the atmosphere in the course of economic activity, which enhances the greenhouse effect in the atmosphere;
  • increase in the mass of atmospheric aerosols;
  • an increase in the amount of thermal energy generated in the process of economic activity entering the atmosphere.

The first of these causes of anthropogenic climate change is of the greatest importance. The essence of "" is as follows. The atmosphere contains a certain concentration of "radiation-active" gases, which are of great importance for life on Earth, since they trap heat in the lower layers of the atmosphere. Without these gases, the temperature of the earth's surface would be about 33°C lower. However, increasing the concentration greenhouse gases(carbon dioxide - C0 2, methane - CH 4, nitrous oxide - N,0, chlorofluorocarbons, etc.) near the earth's surface leads to the formation of a certain "gas curtain", which does not transmit excess infrared radiation from the Earth's surface back into space, as this should be at normal concentrations of these gases. As a result, a significant part of the energy remains in the surface layer, which causes warming at its very surface.

The main contribution to warming is made by carbon dioxide (65% of all sources). The increase in the concentration of carbon dioxide in the atmosphere is determined by the formation of CO 2 as a result of the combustion of coal, oil products and other fuels. The influx of carbon dioxide into the atmosphere is so great that it is technically unfeasible to stop this process in the coming decades. In addition, energy consumption in developing countries is starting to rise rapidly. The gradual increase in the amount of CO and other greenhouse gases in the atmosphere is already having a noticeable impact on the Earth's climate, changing it towards warming. The general trend towards an increase in global average temperature near the earth's surface is intensifying, which has already led to an increase in the 20th century. to an increase in the average air temperature by 0.6°C.

As a result of a fourfold increase in the second half of the 20th century. As a result of carbon emissions, the Earth's atmosphere began to heat up at an increasing rate (Fig. 1). According to UN forecasts, the subsequent global increase in air temperature in the 21st century will be from 1.5 to 4°C.

Rice. 1. Change in the average annual air temperature in the surface layer of the Earth (1860-2000)

The following effects of global warming are predicted:

  • rise in the level of the world ocean due to the melting of glaciers and polar ice (over the past 100 years by 10-25 cm), which, in turn, results in flooding of territories, displacement of the boundaries of marshes and lowland areas, an increase in salinity of water in the mouths of rivers, as well as potential loss of a person's place of residence;
  • change in precipitation (precipitation increases in northern Europe and decreases in southern Europe);
  • change in the hydrological regime, quantity and quality of water resources;
  • impact on ecological systems, agriculture and forestry (mixing of climatic zones in a northerly direction and migration of wild fauna species, changes in the seasonality of growth and productivity of land in agriculture and forestry).

All of the above factors can have a catastrophic impact on human health, the economy and society as a whole. The increasing frequency of droughts and the subsequent crisis in agriculture increase the threat of hunger and social stability in some regions of the world. Difficulties with water supply in countries with a warm climate stimulate the spread of tropical and subtropical diseases. As warming trends intensify, weather patterns become more volatile and climate-related natural disasters become more destructive. The damage caused by natural disasters to the world economy is increasing (Fig. 2). In 1998 alone, it exceeded the damage caused by natural disasters in the entire 1980s, tens of thousands of people died and about 25 million "environmental refugees" were forced to leave their homes.

Rice. 2. Economic damage to the world economy, 1960-2000 (billion US dollars, annually)

At the end of the XX century. mankind came to understand the need to solve one of the most complex and extremely dangerous environmental problems associated with climate change, and in the mid-1970s. began active work in this direction. At the World Climate Conference in Geneva (1979), the foundations of the World Climate Program were laid. In accordance with the resolution of the UN General Assembly on the protection of the global climate for the benefit of present and future generations, the UN Framework Convention on Climate Change (1992) was adopted. The purpose of the convention is to stabilize the concentration of greenhouse gases in the atmosphere at a level that will not have a dangerous impact on the global climate system. Moreover, the solution of this task is supposed to be carried out in a timeframe sufficient for the natural adaptation of ecosystems to climate change and avoiding the threat to food production, as well as ensuring further economic development on a sustainable basis.

To reduce the threat of global warming, it is necessary first of all to reduce carbon dioxide emissions. Most of these emissions come from the burning of fossil fuels, which still provide more than 75% of the world's energy. The rapidly increasing number of cars on the planet increases the risk of further emissions. Stabilization of CO in the atmosphere at a safe level is possible with an overall reduction (by about 60%) of greenhouse gas emissions that cause global warming. Further development of energy-saving technologies and wider use of renewable energy sources can help in this.

At the III Conference of the countries that signed the UN Framework Convention on Climate Change (UNFCCC) in Kyoto, the Kyoto Protocol to the UNFCCC (1997) was adopted, which fixed certain quantitative obligations to reduce greenhouse gas emissions for industrialized countries and countries with economies in transition. At the time of signing the Kyoto Protocol, greenhouse gas emissions were distributed as follows: USA - 36.1%, EU countries - 25.0, Russia - 17.4, Japan - 8.5, countries of Eastern Europe - 7.4, Canada - 3, 3, Australia and New Zealand - 2.3% of global emissions. The implementation of the Kyoto Protocol could lead to significant progress, as the protocol obliges industrialized countries to limit emissions and reduce overall greenhouse gas emissions during the period 2008-2012. by an average of 5% compared to the 1990 level. Achievement of the first group of goals set in the Kyoto Protocol is considered by the UN only as the beginning of movement towards what needs to be done to slow down the process of global warming, and in the long term - to reduce the risk of global climate change.

The world community had high hopes for the 15th UN Conference on Climate Change (Copenhagen, 2009). On the eve of its opening, new data on the distribution of greenhouse gas emissions by individual countries were published: China - 20.8%; USA - 19.9; Russia-5.5; India-4.6; Japan-4.3; Germany - 2.8; Canada - 2.0; Great Britain - 1.8; South Korea - 1.7; Iran - 1.6% of the total CO2 emissions into the atmosphere. The conference developed recommendations to reduce greenhouse gas emissions and annually allocate $100 billion to small states to finance environmental programs until 2020. However, disagreements between developed and developing countries did not allow the adoption of a legally binding document to reduce harmful emissions.

In Russia, a climate doctrine has been developed and approved, in which the state declares that it is ready to allocate resources for systematic climate observations, as well as for fundamental applied research in the field of climate and related fields of science. Russia is concentrating its efforts to the maximum extent possible on reducing greenhouse gas emissions and increasing their absorption by sinks and accumulators. This is supposed to be achieved with the consistent introduction of energy-saving technologies and alternative energy sources. Russia has assumed obligations to further mitigate the anthropogenic impact on the climate: by 2020, to reduce greenhouse gas emissions by 25% compared to 1990 (EU countries - by 20%).

Studying climate change

Plant remains, landforms and glacial deposits, rocks and fossils contain information about significant fluctuations in average temperatures and precipitation throughout geological time. Climate change can also be studied from tree rings, alluvial deposits, ocean and lake sediments, and organic peatlands. Over the past few million years there has been a general cooling of the climate, and now, judging by the continuous reduction of the polar ice sheets, we seem to be at the end of the ice age.

Climate change over a historical period can sometimes be reconstructed from information about crop failures, floods, abandoned settlements, and migrations of peoples. Continuous series of air temperature measurements are available only for meteorological stations located mainly in the Northern Hemisphere. They cover only a little over one century. These data indicate that over the past 100 years, the average temperature on the globe has increased by almost 0.5 °C. This change does not occur smoothly, but abruptly - sharp warmings were replaced by stable stages.

Experts from various fields of knowledge have proposed numerous hypotheses to explain the causes of climate change. Some believe that climatic cycles are determined by periodic fluctuations in solar activity with an interval of about 11 years. Annual and seasonal temperatures could be influenced by changes in the shape of the Earth's orbit, which led to a change in the distance between the Sun and the Earth. Currently, the Earth is closest to the Sun in January, but approximately 10,000 years ago, it was in this position in July. According to another hypothesis, depending on the angle of inclination of the earth's axis, the amount of solar radiation entering the Earth changed, which affected the general circulation of the atmosphere. It is also possible that the polar axis of the Earth occupied a different position. If the geographic poles were at the latitude of the modern equator, then, accordingly, the climatic zones also shifted.

Geographical theories explain long-term climate fluctuations by movements of the earth's crust and changes in the position of continents and oceans. In the light of global plate tectonics, continents have moved over geological time. As a result, their position in relation to the oceans changed, as well as in latitude, etc.

Large masses of dust and gases released into the atmosphere during volcanic eruptions occasionally became an obstacle to solar radiation and led to cooling of the earth's surface. An increase in the concentration of certain gases in the atmosphere exacerbates the overall warming trend.

The impact of climate on the life and economic activity of people

A person living in a certain area gets used to, adapts (from Latin adaptation - adaptation) to the conditions of his environment, including the climatic features of the area. His clothes, shoes, food, housing, occupations are the result of this adaptation. It has a significant impact on economic activity.

Adaptation is necessary for a person when climatic conditions change.