geological age of our planet is about 4.5 billion years old.During this period, the Earth has changed dramatically.The composition of the atmosphere, the mass of the planet's climate - at the beginning of the existence of everything was completely different.Molten ball slowly becoming the way we are used to seeing today.Faced tectonic plates to form new mountain ranges.On slowly cooling down the planet formed the seas and oceans.They appeared and disappeared continents, changing their shape and size.The earth began to slowly rotate.There were first plants and then life itself.Accordingly, over the past billions of years on the planet there have been dramatic changes in the hydrologic cycle, heat exchange and atmospheric composition.Climate change is happening throughout the existence of the Earth.
Holocene epoch Holocene - Quaternary period of the Cenozoic era.In other words, this is the era that began about 12,000 years ago and continues to the present.Holocene began with the end of the Ice Age, and since then the climate change on the planet went toward global warming.This is often called interglacial epoch, as the entire planet's climate history there have been several ice ages.
Last global cooling occurred about 110 thousand years ago.About 14 thousand years ago began warming gradually gripped the entire planet.Glaciers that covered at that time most of the Northern Hemisphere began to melt and collapse.Naturally, none of this happened overnight.For a very long period, the planet was shaken by strong temperature fluctuations, the glaciers were advancing, then retreating again.All this affects the level of the oceans.
Holocene period
During numerous studies, scientists have decided to share a few Holocene periods of time depending on the climate.Approximately 12-10 thousand years ago the ice sheets gone, come post-glacial.In Europe, began to disappear tundra, it was replaced by birch, pine and taiga forests.This time, called the arctic and subarctic period.
was followed by the era of boreal.Taiga pushed into the tundra farther north.In Southern Europe, there were broad-leaved forests.At this time, the climate was mostly cool and dry.
Approximately 6000 years ago the Atlantic era, during which the air was warm and humid, much warmer modern.This time period is considered to be the entire Holocene climatic optimum.Half of Iceland was covered with birch forests.Europe is full of a wide variety of heat-loving plants.At the same time the length of the temperate forests has been significantly further north.On the shores of the Barents Sea grew coniferous forests, taiga and reached Cape Chelyuskin.In place of the modern Sahara was savannah, and the water level in Lake Chad was above the present 40 meters.
Then again, there was a change of climate.There was a cold snap, which lasted about 2000 years.This time period is called subboreal.Mountain ranges in Alaska, Iceland, glaciers in the Alps have got.Landscape zones have shifted closer to the equator.
about 2.5 thousand years ago began the last period of the modern Holocene - Subatlantic.The climate of this era became cooler and wetter.Began to appear peatlands, tundra began to gradually settle in the forest, and the forest - on the steppe.Around the 14th century the climate cooling that led to the Little Ice Age, which lasted until the mid-19th century.At this time, we recorded the invasion of glaciers in mountain ranges of Northern Europe, Iceland, Alaska and in the Andes.In different parts of the globe climate change not in sync.The reasons for the onset of the Little Ice Age are still unknown.According to scientists, the climate could change due to increases in volcanic eruptions and reduce the concentration of carbon dioxide in the atmosphere.
Start meteorological
first meteorological station appeared in the late 18th century.Since that time, is being monitored continually climatic fluctuations.You can credibly claim that the warming that began after the Little Ice Age, and continues to the present.
Since the late 19th century recorded growth in average global temperature of the planet.In the mid-20th century there was a slight chill that had no effect on the climate as a whole.Since the mid-70s again became warmer.Scientists estimate that over the last century the global temperature of the Earth has increased by 0.74 degrees.The highest growth of this indicator was recorded in the last 30 years.
Climate change directly affects the state of the oceans.Increasing global temperature leads to expansion of water, and hence to increase its level.Also coming changes in precipitation patterns, which in turn can influence the flow of rivers and glaciers.
According to observations, global sea level over the past 100 years has grown by 5 cm. Global warming, scientists associated with the increasing concentration of carbon dioxide and a significant increase in the greenhouse effect.
climatic factors
Scientists have conducted many archaeological studies and concluded that the climate of the planet have repeatedly changed dramatically.Many hypotheses have been put forward in this regard.According to one view, if the distance between the Earth and the Sun will remain the same, as well as the speed of the planet's rotation and axis tilt angle, the climate will remain stable.
External factors of climate change:
- change in solar radiation leads to the transformation of solar radiation fluxes.
- movement of tectonic plates affect the orography of land, as well as the level of the ocean and its circulation.
- gas composition of the atmosphere, in particular the concentration of methane and carbon dioxide.
- Changing the inclination of the axis of rotation of the Earth.
- Changing the orbit of the planet relative to the sun.
- Earthly and cosmic catastrophes.
human activity and its impact on climate
causes of climate change are linked including the fact that humanity throughout its existence interfered with nature.Cutting down forests, plowing of land reclamation and so on. N. Lead to the transformation of humidity and wind conditions.
When people make changes in the natural environment, draining swamps, creating artificial ponds, cutting down forests and planting new ones, building cities, and so on. N., Changing climate.Wood strongly affects the wind regime, which determines how the snow will fall, as the soil is chilled.
Green areas in cities reduce the impact of solar radiation, increase air humidity, reducing the temperature difference between day and night time, reduce dust air.
If people cut down forests on the hills, in the future, this leads to soil erosion.Also, reducing the number of trees reduces global temperatures.However, this means increasing the concentration of carbon dioxide in the air, which is not only absorbed by trees, but also additionally allocated by the decomposition of wood.All this compensates for the drop in global temperatures and leads to its increase.
industry and its impact on the climate
causes of climate change lie not only in a general warming, but also in the activities of mankind.Users have increased the concentration of airborne substances such as carbon dioxide, nitrous oxide, methane, tropospheric ozone, hlorftoruglevody.All of this eventually leads to the greenhouse effect and the consequences can be irreversible.
Daily industry spew into the air a lot of dangerous gases.Is commonly used vehicles pollute the atmosphere with their emissions.Lots of carbon dioxide produced from the burning of oil and coal.Even agriculture causes considerable damage to the atmosphere.Approximately 14% of all emissions of greenhouse gases has originated in this area.This plowing fields, and the burning of waste, savanna burning, manure, fertilizer, animal husbandry and so on. N. The greenhouse effect helps to maintain the thermal balance of the planet, but human activity enhances this effect at times.And it can lead to disaster.
Why should I be afraid of climate change?
97% of the world climate scientists believe that in the last 100 years, all greatly transformed.And the main problem of climate change - it is human activities.You can not reliably tell how serious this situation is, but there are plenty of reasons for concern:
- 'll have to redraw the map of the world.The fact is that if the glaciers melt eternal Arctic and Antarctica, is about 2% of world reserves of water, the sea level will rise to 150 meters.According to rough Scientists predict that the Arctic will be ice-free in the summer of 2050.Suffer a lot of coastal cities, a number of island states will disappear entirely.
- threats to global food shortages.Already the world's population is over seven billion people.In the next 50 years it is expected that the population will be more than another two billion.If this trend of increasing life expectancy and lower infant mortality rates in 2050 of food will be required 70% more current figures.By that time, many regions may be flooded.Raising the temperature of the plains turn into a desert.Grain crops are in danger.
- Melting Arctic and Antarctica will lead to global emissions of carbon dioxide and methane.Under the eternal ice is a huge amount of greenhouse gases.Breaking into the atmosphere, they are many times will increase the greenhouse effect, which would have catastrophic consequences for all mankind.
- Ocean acidification.About a third of the carbon dioxide accumulates in the ocean, but the glut of this gas will lead to oxidation of water.The Industrial Revolution has led to an increase in oxidation of 30%.
- mass extinctions.Of course, extinction is a natural process of evolution.But lately, too many dying animals and plants, and the reason for this - the activities of mankind.
- weather disasters.Global warming leads to disaster.Droughts, floods, hurricanes, earthquakes, tsunamis - everything becomes more and more intense.Now the extreme weather conditions killed up to 106,000 people a year, and this figure will only grow.
- inevitability of war.Droughts and floods will transform entire regions into uninhabitable, and so people will look for an opportunity to survive.Start a war for resources.
- Changing ocean currents.The main "heater" Europe is the Gulf Stream - the warm current flowing along the Atlantic Ocean.Already for this falls to the bottom and change its direction.If the process continues, Europe will be under a layer of snow.Across the globe will have big problems with the weather.
- Climate change is already costing billions.It is not known how much this figure could rise if all continues.
- Hacking Earth.No one can predict how much will change the planet from global warming.Scientists are developing ways to prevent symptoms.One of these is the ejection of large amounts of sulfur into the atmosphere.This will simulate the effect of a huge volcanic eruption and lead to a cooling of the planet due to blockage of sunlight.It is not known what impact this system is really not whether humanity will make it worse.
UN Convention
Most governments of the planet seriously afraid of what might be the consequences of climate change.More than 20 years ago it was created by an international treaty - the Framework Convention of the United Nations on Climate Change.Here we consider all possible measures to prevent global warming.Now the Convention has been ratified by 186 countries, including Russia.All participants differentiated into 3 groups: the industrialized countries, countries with economic development and developing countries.
UN Convention on Climate Change is fighting for the reduction in growth of greenhouse gases in the atmosphere and further stabilization performance.This can be achieved either by increasing flow of greenhouse gases from the atmosphere, either by reducing their emissions.For the first variant you need a large number of young forests, which absorb carbon dioxide from the atmosphere, while the second option would be achieved if the lower consumption of fossil fuels.All ratifying countries agree that the world is global climate change.The UN is ready to do everything possible to mitigate the effects of the impending strike.
Many countries participating in the Convention, concluded that the most effective are joint projects and programs.Currently there are more than 150 such projects.Officially, Russia 9 runs similar programs, and unofficially - over 40.
In late 1997, the Convention on Climate Change signed the Kyoto Protocol, which prescribes that the countries with economies in transition commit themselves to reduce greenhouse gases.Protocol has been ratified by 35 countries.
Our country also participated in the implementation of this Protocol.Changing climate in Russia has led to the fact that the number of natural disasters has doubled.Even if we consider that in the territory of boreal forests are located, they can not cope with all the greenhouse gas emissions.It should improve and increase the forest ecosystems, to carry out large-scale activities to reduce emissions from industrial enterprises.
Predictions of global warming
essence of climate change in the last century is global warming.In the worst projected further irrational human activities can raise the Earth's temperature at around 11 degrees.Climate change will be irreversible.Slow rotation of the planet, die set of animal and plant species.Sea levels will rise so much that many of the island will be flooded and most of the coastal areas.Gulf Stream will change its course, leading to a new Little Ice Age in Europe.There will be happening throughout disasters, floods, tornadoes, hurricanes, droughts, tsunamis and so on. N. Will begin melting ice in the Arctic and Antarctica.
for human consequences would be disastrous.Apart from the need to survive in conditions of strong natural anomalies in humans is a lot of other problems.In particular, the number of cardiovascular diseases, respiratory diseases, psychological disorders, outbreaks begin.Will feel an acute shortage of food and drinking water.
What to do?
To prevent climate change, we must first reduce the level of greenhouse gases in the atmosphere.Humanity must move to new energy sources, which should be a low-carb, and renewable.Sooner or later, before the world community will rise sharply this issue, as now used resource - mineral fuels - non-renewable.Someday scientists will create new, more efficient technologies.
also necessary to reduce the level of carbon dioxide in the atmosphere and help with this can only be the restoration of forest areas.
required to use best efforts to stabilize the global temperature on Earth.But even if it does not succeed, mankind should try to achieve the minimum effects of global warming.
