The geological age of our planet is approximately 4.5 billion years. During this period, the Earth has changed dramatically. The composition of the atmosphere, the mass of the planet itself, the climate - at the beginning of existence, everything was completely different. The red-hot ball very slowly became the way we are used to seeing it now. Tectonic plates collided, forming ever new mountain systems. On a gradually cooling planet, seas and oceans formed. Continents appeared and disappeared, their shape and size changed. The earth began to rotate more slowly. The first plants appeared, and then life itself. Accordingly, over the past billions of years, cardinal changes have taken place on the planet in moisture circulation, heat circulation and atmospheric composition. Climate change has occurred throughout the existence of the Earth.
The Holocene Epoch
The Holocene is part of the Quaternary period of the Cenozoic era. In other words, this is an era that began approximately 12 thousand years ago and continues to the present. The Holocene began with the end of the Ice Age, and since then climate change hasthe planet was heading towards global warming. This era is often called the interglacial, as there have been several ice ages throughout the entire climatic history of the planet.
The last global cooling occurred approximately 110 thousand years ago. About 14 thousand years ago, warming began, gradually covering the entire planet. The glaciers that at that time covered most of the Northern Hemisphere began to melt and collapse. Naturally, all this did not happen overnight. For a very long period, the planet was shaken by strong temperature fluctuations, glaciers either advanced or retreated again. All this also affected the level of the World Ocean.
Periods of the Holocene
During numerous studies, scientists decided to divide the Holocene into several time periods depending on the climate. Approximately 12-10 thousand years ago, the ice sheets disappeared, the post-glacial period began. In Europe, the tundra began to disappear, it was replaced by birch, pine and taiga forests. This time is called the Arctic and Subarctic period.
Then came the boreal era. The taiga pushed the tundra further north. Broad-leaved forests appeared in Southern Europe. During this time, the climate was predominantly cool and dry.
Approximately 6 thousand years ago, the Atlantean era began, during which the air became warm and humid, much warmer than today. This period of time is considered the climatic optimum of the entire Holocene. Half of the territory of Iceland was covered with birch forests. Europe aboundeda wide variety of thermophilic plants. At the same time, the extent of temperate forests was much further north. Dark coniferous forests grew on the shores of the Barents Sea, and the taiga reached Cape Chelyuskin. On the site of the modern Sahara there was a savannah, and the water level in Lake Chad was 40 meters higher than the modern one.
Then climate change happened again. A cold snap set in, lasting about 2,000 years. This period of time is called subboreal. Mountain ranges in Alaska, Iceland, in the Alps acquired glaciers. Landscape zones have shifted closer to the equator.
Approximately 2.5 thousand years ago, the last period of the modern Holocene, the Subatlantic, began. The climate of this era became cooler and wetter. Peat bogs began to appear, the tundra gradually began to press on the forests, and the forests on the steppes. Around the 14th century, the cooling of the climate began, leading to the Little Ice Age, which lasted until the middle of the 19th century. At this time, invasions of glaciers were recorded in the mountain ranges of Northern Europe, Iceland, Alaska and the Andes. In different parts of the world, the climate has not changed synchronously. The causes of the onset of the Little Ice Age are still unknown. According to scientists, the climate could change due to increases in volcanic eruptions and a decrease in the concentration of carbon dioxide in the atmosphere.
Begin meteorological observations
The first meteorological stations appeared at the end of the 18th century. Since that time, constant monitoring of climatic fluctuations has been carried out. It can be reliably stated thatwarming that began after the Little Ice Age continues to this day.
Since the end of the 19th century, an increase in the average global temperature of the planet has been recorded. In the middle of the 20th century there was a slight cooling, which did not affect the climate in general. Since the mid-1970s, it has become warmer again. According to scientists, over the past century, the global temperature of the Earth has increased by 0.74 degrees. The greatest growth of this indicator was recorded in the last 30 years.
Climate change invariably affects the state of the oceans. An increase in global temperature leads to the expansion of water, and hence to an increase in its level. There are also changes in the distribution of precipitation, which, in turn, can affect the flow of rivers and glaciers.
According to observations, the level of the World Ocean over the past 100 years has risen by 5 cm. Scientists attribute climate warming to an increase in the concentration of carbon dioxide and a significant increase in the greenhouse effect.
Climate factors
Scientists have conducted many archaeological studies and came to the conclusion that the climate of the planet has changed dramatically more than once. Many hypotheses have been put forward in this regard. According to one opinion, if the distance between the Earth and the Sun remains the same, as well as the speed of rotation of the planet and the angle of the axis, then the climate will remain stable.
External drivers of climate change:
- Change in solar radiation leads to transformation of solar radiation flows.
- Movements of tectonic plates affect the orography of land, as well as the level of the ocean and itscirculation.
- Gas composition of the atmosphere, in particular the concentration of methane and carbon dioxide.
- Change in the tilt of the Earth's axis of rotation.
- Changing the parameters of the planet's orbit with respect to the Sun.
- Earth and space disasters.
Human activities and their impact on climate
The causes of climate change are connected, among other things, with the fact that humanity has interfered with nature throughout its existence. Deforestation, plowing, land reclamation, etc. lead to transformations in the humidity and wind regimes.
When people make changes to the environment, draining swamps, creating artificial reservoirs, cutting down forests or planting new ones, building cities, etc., the microclimate changes. The forest strongly influences the wind regime, which determines how the snow cover will fall, how much the soil will freeze.
Green spaces in cities reduce the impact of solar radiation, increase air humidity, reduce the temperature difference between day and evening, reduce air pollution.
If people cut down forests on the hills, then in the future it leads to soil erosion. Also, the decrease in the number of trees reduces the global temperature. However, this means an increase in the concentration of carbon dioxide in the air, which is not only not absorbed by trees, but is also additionally released during the decomposition of wood. All this compensates for the decrease in global temperature and leads to its increase.
Industry and its impact onclimate
The causes of climate change lie not only in general warming, but also in the activities of mankind. People have increased the concentration in the air of substances such as carbon dioxide, nitrous oxide, methane, tropospheric ozone, chlorofluorocarbons. All this ultimately leads to an increase in the greenhouse effect, and the consequences may be irreversible.
Daily, industrial plants emit many dangerous gases into the air. Transportation is used everywhere, polluting the atmosphere with its emissions. A lot of carbon dioxide is formed when oil and coal are burned. Even agriculture causes considerable damage to the atmosphere. Approximately 14% of all greenhouse gas emissions come from this sector. This includes plowing fields, burning waste, burning the savannah, manure, fertilizers, animal husbandry, etc. The greenhouse effect helps maintain the temperature balance on the planet, but human activity enhances this effect at times. And that could lead to disaster.
Why should we be afraid of climate change?
97% of the world's climatologists are sure that everything has changed a lot in the last 100 years. And the main problem of climate change is anthropogenic activity. It's impossible to say for sure how serious this situation is, but there are plenty of reasons to be concerned:
- We'll have to redraw the world map. The fact is that if the eternal glaciers of the Arctic and Antarctica, which make up approximately 2% of the world's water reserves, melt, the ocean level will rise by 150 meters. According to rough forecastsscientists, the Arctic will be free of ice in the summer of 2050. Many coastal cities will suffer, a number of island states will disappear completely.
- The threat of global food shortages. Already, the world's population is over seven billion people. In the next 50 years, the population is expected to increase by another two billion. With the current trend towards increasing life expectancy and decreasing infant mortality in 2050, food will be required 70% more than the current figures. By that time, many regions may be flooded. Rising temperatures will turn part of the plain into a desert. Crops will be in danger.
- The melting of the Arctic and Antarctica will lead to global emissions of carbon dioxide and methane. Under the eternal ice is a huge amount of greenhouse gases. Having escaped into the atmosphere, they will multiply the greenhouse effect, which will lead to catastrophic consequences for all mankind.
- Ocean acidification. Approximately a third of carbon dioxide ends up in the ocean, but a supersaturation of this gas will lead to water acidification. The Industrial Revolution has already resulted in a 30% increase in oxidation.
- Mass extinctions of species. Of course, extinction is a natural process of evolution. But lately, too many animals and plants are dying out, and the reason for this is the activity of mankind.
- Weather disasters. Global warming leads to disasters. Droughts, floods, hurricanes, earthquakes, tsunamis - everything is becoming more frequent and intense. Extreme weather is now killing up to 106,000 people a year, and that number is only going to rise.
- The inevitability of wars. Droughts and floods will turn entire regions uninhabitable, which means people will look for ways to survive. Resource wars will begin.
- Change in ocean currents. The main "heater" of Europe is the Gulf Stream - a warm current flowing through the Atlantic Ocean. Already now this current is sinking to the bottom and changing its direction. If the process continues, then Europe will be under a layer of snow. There will be big weather problems around the globe.
- Climate change is already costing billions. It is not known how much this figure could grow if things continue.
- Earth Hacking. No one can predict how much the planet will change as a result of global warming. Scientists are developing ways to prevent symptoms. One of them is the release of large volumes of sulfur into the atmosphere. This will simulate the effect of a huge volcanic eruption and cause the planet to cool down due to the blockage of sunlight. However, it is not known how this system will actually affect and whether it will only make humanity worse.
UN Convention
Governments in most countries around the world are seriously concerned about the consequences of climate change. More than 20 years ago, an international treaty was created - the United Nations Framework Convention on Climate Change. All possible measures are considered here to preventglobal warming. Now the convention has been ratified by 186 countries, including Russia. All participants are differentiated into 3 groups: industrialized countries, countries with economic development and developing countries.
The UN Climate Change Convention is fighting to reduce the growth of greenhouse gases in the atmosphere and further stabilize indicators. This can be achieved either by increasing the sink of greenhouse gases from the atmosphere, or by reducing their emissions. The first option requires a large number of young forests that will absorb carbon dioxide from the atmosphere, and the second option will be achieved if the consumption of fossil fuels is reduced. All ratified countries agree that the world is undergoing global climate change. The UN is ready to do everything possible to mitigate the consequences of the impending strike.
Many countries participating in the convention have come to the conclusion that joint projects and programs will be the most effective. Currently, there are more than 150 such projects. Officially, there are 9 such programs in Russia, and more than 40 unofficially.
At the end of 1997, the Convention on Climate Change signed the Kyoto Protocol, which stipulated that countries with economies in transition undertake obligations to reduce greenhouse gas emissions. Protocol ratified by 35 countries.
Our country also took part in the implementation of this protocol. Climate change in Russia has doubled the number of natural disasters. Eventake into account that boreal forests are located on the territory of the state, they cannot cope with all greenhouse gas emissions. It is necessary to improve and increase forest ecosystems, to carry out large-scale measures to reduce emissions from industrial enterprises.
Predictions of the consequences of global warming
The essence of climate change in the last century is global warming. According to the worst forecasts, further irrational activities of mankind can increase the temperature of the Earth by 11 degrees. Climate change will be irreversible. The rotation of the planet will slow down, many species of animals and plants will die. The level of the World Ocean will rise so much that many islands and most of the coastal areas will be flooded. The Gulf Stream will change its course, leading to a new Little Ice Age in Europe. There will be widespread cataclysms, floods, tornadoes, hurricanes, droughts, tsunamis, etc. The melting of the ice of the Arctic and Antarctica will begin.
The consequences for humanity will be catastrophic. In addition to the need to survive in conditions of strong natural anomalies, people will have many other problems. In particular, the number of cardiovascular diseases, respiratory diseases, psychological disorders will increase, outbreaks of epidemics will begin. There will be severe shortages of food and drinking water.
What to do?
To avoid the effects of climate change, we must first reduce the level of greenhouse gases in the atmosphere. Humanityshould switch to new energy sources, which should be low-carbohydrate and renewable. Sooner or later, this issue will be acute for the world community, since the resource currently used - mineral fuel - is non-renewable. Someday, scientists will have to create new, more efficient technologies.
It is also necessary to reduce the level of carbon dioxide in the atmosphere, and only restoration of forest areas can help with this.
Maximum efforts are required to stabilize the global temperature on Earth. But even if that fails, humanity must try to minimize the effects of global warming.
