Why is the level of CO2 in the atmosphere so alarming for scientists? & Nbsp. Do volcanoes emit more carbon dioxide into the atmosphere than humans? Who gives off carbon dioxide

What Science Says ...

Humanity produces 100 times more CO2 than volcanoes.

A basic level of

The earth contains a huge amount of carbon, far more than what scientists estimate is in the atmosphere or in the oceans. Some of this carbon is slowly released from rocks in the form of CO2 through volcanoes and hot springs, it is an important part of the natural carbon cycle. According to reviews of scientific publications Moerner and Etiope (2002) and Kerrick (2001), the emission estimates range from 65 to 319 million tons per year. Contradictory claims that volcanoes, especially underwater ones, produce much larger amounts of CO2, are not based on any publications by scientists working on this topic.

The combustion of fossil fuels and land-use changes result in approximately 30 billion tons of carbon dioxide per year, according to the EIA. This value is about 100 times greater than the maximum estimate of volcanic emissions. Our understanding of the contribution of volcanoes to changes in the concentration of CO2 in the earth's atmosphere will be obviously erroneous if we do not recognize this contribution as very insignificant.

Volcanoes can - and do - affect climate over time ranges of the order of several years, but this is due to the release of sulfate aerosols into the upper atmosphere during large eruptions that occur sporadically every century.

Advanced level

Volcanoes emit CO2 both on land and underwater. Submarine volcanoes emit 66 to 97 million tons of CO2 per year. However, this is counterbalanced by carbon uptake by the lava that forms on the ocean floor. Consequently, underwater volcanoes have little effect on atmospheric CO2 levels. Subaerial volcanoes make a larger contribution (subaerial means "under the air", this is a reference to terrestrial volcanoes). Subaerial volcanoes emit 242 million tonnes of CO2 per year (Mörner and Etiope (2002)).

Humans currently emit about 29 billion tonnes of CO2 per year (EIA). Human CO2 emissions are more than 100 times that of volcanic CO2. This is evident when comparing atmospheric CO2 levels with volcanic activity since 1960. Even violent volcanic eruptions such as Pinatubo, El Chikon and Agung have had little noticeable impact on CO2 levels. In fact, after a volcanic eruption, the rate of CO2 change even drops slightly, possibly due to the cooling effect of aerosols.

Figure 1: Atmospheric CO2 levels measured at Mauna Loa, Hawaii (NOAA) (left: atmospheric CO2, parts per million) and stratospheric aerosol optical depth (right) at 50 nm (NASA GISS).

The Mount Pinatubo eruption released 42 million tonnes of CO2 (Gerlach et al 1996). Compare this to human emissions in 1991: 23 billion tonnes of CO2 (CDIAC). The strongest eruption in half a century has accounted for 0.2% of human CO2 emissions this year.

Advanced level translation completed

Image copyright Getty Images Image caption Due to harmful emissions in the world, 41 billion tons of carbon dioxide will be produced by the end of 2017

In 2017, global carbon dioxide emissions are projected to rise for the first time in four years. According to scientists, the main reason is the intensive consumption of coal in China, which is experiencing rapid economic growth.

Scientists cannot yet say for sure whether this increase in emissions will be a one-time one, or a new phase of growth will begin in 2017.

According to scientists, the planet must pass a peak before 2020 in order to reduce the risk of global warming in the next century.

The Global Carbon Project has been analyzing and publishing data on the dynamics of carbon dioxide emissions since 2006.

The number of emissions grew by about 3% per year, but then from 2014 to 2016 either decreased or remained at the same level.

According to the latest data, in 2017, human activities led to the fact that emissions around the world increased by 2%.

There is no data yet on the exact number of emissions, but all researchers agree that their number is increasing.

"CO2 emissions around the world are showing strong growth after three years of stability. This is very sad," says research team leader Professor Corinne Le Queré of the University of East Anglia.

“Human activities are causing 41 billion tonnes of carbon dioxide to be produced by the end of 2017. We have almost no time left to maintain the annual global warming at two degrees Celsius, not to mention one and a half degrees, "she continues.

Image copyright Getty Images Image caption The active use of coal has led to the fact that the amount of carbon dioxide in the atmosphere began to rise for the first time in four years.

China is playing the most important role in the current rise. It accounts for 28% of global emissions. Due to heavy use of coal, the country's emissions rose by 3.5% in 2017.

Another reason is that water levels in Chinese rivers are dropping. Because of this, the amount of energy that is generated by hydroelectric power plants is reduced. To bridge the gap, the country replaces the energy gap by using gas and coal.

US emissions continue to decline, but not as intensely as originally anticipated.

Due to the rise in prices for natural gas and electricity, their consumption has dropped or has been partially replaced by renewable energy sources.

US coal consumption has also increased this year, but not significantly - by only half a percent.

India's emissions are projected to rise by 2% this year. This is significantly lower than in the last decade, during which the average annual growth was about 6%.

However, experts are confident that this could turn out to be a temporary fluctuation caused by several factors making it difficult to use oil and cement in the country.

Time to act

In Europe, the decline is also slower than forecast. In 2017, the decline was only 0.2%, with an average of 2.2% over ten years.

According to Professor Le Querre, the hottest topic around the world remains the use of gas and oil.

“Consumption of coal rises and falls, while there is no noticeable change in the use of gas and oil. And this is quite alarming,” she explains.

Image copyright Getty Images Image caption Scientists urge not to wait for the entry into force of the Paris Agreement, but to change, first of all, the national climate policy

The report of her study group was presented at the UN Conference in Bonn, where the future provisions of the Paris Agreement are discussed.

Scientists who worked on the study argue that it is necessary to act faster.

"A huge number of diplomats are trying to work out new rules. But this is all pretty pointless until they go to their countries and take drastic action on climate policy. This is the weakest point right now," says Dr. Glen Peters of the Center for International Climate Research in Norway. ...

“Countries should be more active in developing climate policies, but everything, on the contrary, is moving backward,” he continues.

The report is likely to create even greater tension between developing and developed countries.

There is growing dissatisfaction with the fact that the focus is on the measures to be taken under the Paris Agreement in the future. Until this moment, practically nothing is provided.

Developing countries expect their development partners to tighten carbon caps over the next three years.

“The climate will not allow us to wait until 2020 for the Paris Agreement to enter into force,” said Nicaraguan spokesman Paul Oquist.

“Climate change is happening right now and it is important that emission reductions become the main topic of discussion at this summit,” he concludes.

1 Man and Climate.

2 Introduction.

Relationship between energy consumption, economic activity and income

in atmosphere.

Energy consumption and carbon dioxide emissions.

3 Carbon in nature.

Carbon isotopes.

4 Carbon in the atmosphere.

Atmospheric carbon dioxide.

Carbon in the soil.

5 Predictions of the concentration of carbon dioxide in the atmosphere for the future. Main conclusions.

6 Bibliography.

Introduction.

Human activity has already reached such a level of development at which its influence on nature becomes global. Natural systems - atmosphere, land, ocean - as well as life on the planet as a whole are subject to these influences. It is known that over the past century, the content in the atmosphere of some gaseous constituents, such as carbon dioxide (

), nitrous oxide (), methane () and tropospheric ozone (). Additionally, other gases that were not natural components of the global ecosystem entered the atmosphere. The main ones are chlorofluorocarbons. These gas impurities absorb and emit radiation and are therefore capable of influencing the Earth's climate. All these gases together can be called greenhouse gases.

The notion that the climate could change as a result of the release of carbon dioxide into the atmosphere is not yet emerging. Arrhenius pointed out that burning fossil fuels could lead to an increase in the concentration of atmospheric

and thereby change the radiation balance of the Earth. At present, we know approximately how much was released into the atmosphere due to the burning of fossil fuels and changes in land use (deforestation and expansion of agricultural areas), and the observed increase in atmospheric concentration can be associated with human activities.

Mechanism of action

on the climate lies in the so-called greenhouse effect. While for solar shortwave radiation it is transparent, escaping from earth surface long-wave radiation this gas absorbs and emits the absorbed energy in all directions. As a result of this effect, an increase in atmospheric concentration leads to heating of the Earth's surface and the lower atmosphere. The continuing rise in atmospheric concentration could lead to a change in the global climate, therefore forecasting future carbon dioxide concentrations is an important task.

Release of carbon dioxide into the atmosphere

as a result of industrial

emissions.

The main anthropogenic source of emissions

is the combustion of all kinds of carbonaceous fuels. Currently economic development usually associated with the growth of industrialization. Historically, economic recovery depends on the availability of available energy sources and the amount of fossil fuels burned. Data on economic and energy development for most countries for the period 1860-1973. Indicate not only economic growth, but also an increase in energy consumption. However, one is not a consequence of the other. Since 1973, in many countries, there has been a decrease in specific energy consumption with an increase in real energy prices. A recent study of industrial energy use in the United States showed that the ratio of primary energy consumption to the economic equivalent of goods produced has been steadily decreasing since 1920. More efficient use of energy is being achieved through improvements in industrial technology, vehicles and building design. In addition, in a number of industrialized countries there have been shifts in the structure of the economy, expressed in the transition from the development of raw materials and processing industries to the expansion of industries producing the final product.

The minimum level of energy consumption per capita currently required to meet the needs of medicine, education and recreation varies significantly from region to region and from country to country. In many developing countries, significant increases in per capita consumption of high quality fuels are essential for achieving higher living standards. It now seems likely that continued economic growth and the achievement of the desired standard of living are not related to the level of energy consumption per capita, but this process is still not well understood.

It can be assumed that before the middle of the next century, the economies of most countries will be able to adapt to higher energy prices, reducing the need for labor and other types of resources, as well as increasing the speed of processing and transmitting information, or, possibly, changing the structure of the economic balance between the production of goods. and the provision of services. Thus, the rate of industrial emissions will directly depend on the choice of a strategy for the development of energy with a particular share of the use of coal or nuclear fuel in the energy system.

.

Energy consumption and emissions

carbon dioxide.

Energy is not produced for the sake of energy production itself. In industrialized countries, most of the energy generated comes from industry, transportation, heating and cooling of buildings. Many recent studies have shown that the current level of energy consumption in industrialized mills can be significantly reduced through the use of energy-saving technologies. It was calculated that if the United States switched, in the production of consumer goods and in the service sector, to the least energy-intensive technologies with the same production volume, then the amount released into the atmosphere

would decrease by 25%. The resulting reduction in emissions for the whole globe would be 7%. A similar effect would have occurred in other industrialized countries. A further reduction in the rate of entry into the atmosphere can be achieved by changing the structure of the economy as a result of the introduction of more efficient methods of production of goods and improvements in the provision of services to the population.

Carbon in nature.

Among the multitude chemical elements, without which the existence of life on Earth is impossible, carbon is the main one. Chemical transformations of organic substances are associated with the ability of the carbon atom to form long covalent chains and rings. The biogeochemical cycle of carbon is naturally very complex, since it includes not only the functioning of all forms of life on Earth, but also the transfer of inorganic substances both between different reservoirs of carbon and within them. The main reservoirs of carbon are the atmosphere, continental biomass, including soils, the hydrosphere with marine biota and the lithosphere. Over the past two centuries, changes in carbon fluxes have taken place in the atmosphere - biosphere - hydrosphere system, the intensity of which is about an order of magnitude higher than the intensity of the geological processes of the transfer of this element. For this reason, one should confine oneself to the analysis of interactions within this system, including soils.

Basic chemical compounds and reactions.

More than a million carbon compounds are known, thousands of which are involved in biological processes. Carbon atoms can be in one of nine possible oxidation states: from + IV to -IV. The most common phenomenon is complete oxidation, i.e. + IV, examples of such compounds are

and . More than 99% of the carbon in the atmosphere is contained in the form of carbon dioxide. About 97% of carbon in the oceans exists in dissolved form (elemental carbon is present in the atmosphere in small quantities in the form of graphite and diamond, and in soil - in the form charcoal... The assimilation of carbon in the process of photosynthesis leads to the formation of reduced carbon, which is present in biota, dead organic matter in the soil, in the upper layers of sedimentary rocks in the form of coal, oil and gas buried at great depths, and in the lithosphere in the form of scattered under-oxidized carbon. Some gaseous compounds containing under-oxidized carbon, in particular methane, enter the atmosphere during the reduction of substances that occurs in anaerobic processes. Although bacterial decomposition produces several different gaseous compounds, they are rapidly oxidized and can be considered to be entering the system. Methane is an exception as it also contributes to the greenhouse effect. The oceans contain a significant amount of dissolved organic carbon compounds, the oxidation processes of which are not yet well known.

Global carbon dioxide emissions hit record highs last year. According to the report of the International Energy Agency (IEA), in 2018 they amounted to 33 billion tons.

“With increased energy demand in 2018, global energy-related CO2 emissions rose 1.7% year-on-year to a historic high of 33.1 Gt CO2,” the study authors note. "85% of the increase in emissions came from China, India and the US, while they fell in Germany, Japan, Mexico, France and the UK."

The dramatic increase in energy demand came as “a surprise to many” and made it even more difficult for countries to achieve their targets. global climate, said in this regard the head of the IEA Fatih Birol.

“We are seeing an extraordinary growth in global energy demand, which is growing at the fastest pace in the current decade,” the Financial Times quoted Birol as saying. At the same time, in his opinion, one can hardly expect the same growth rates in energy demand in 2019.

However, CO2 emissions are only part of the problem. According to an earlier IEA report, oil and gas production, despite active measures taken by oil companies, accounts for a very significant part of the world's methane emissions.

In particular, activities related to the production, transportation, processing and consumption of hydrocarbons account for 13% of methane emissions worldwide. Leaks occur at all stages of the production cycle, and global oil and gas companies are not yet able to accurately measure the volume of these leaks.

In general, human activities account for 60% of global methane emissions, the remaining 40% are natural gas seepage from deep soil layers, bog emissions, animal waste products and decay of dead vegetation.

It is curious, however, that the American aerospace agency NASA assesses the situation differently. At the beginning of last year, the agency released the results of a new study, according to which a serious increase in the concentration of methane in the atmosphere in last years cannot be attributed to cattle breeding and the evaporation of growing "permafrost" swamps.

More than half of the emissions of this greenhouse gas are on the conscience of the global fuel industry. The final report, published in the journal Nature Communications, notes that the average annual methane emissions are now between 12 and 19 million tons per year.

Previously, such a spread was explained by fluctuations in the number of cattle, especially cows, one of the main emitters of methane, and also by the gradual melting of permafrost, leading to the formation of large swamps saturated with this gas.

However, NASA satellite studies have shown that methane emissions from the production and use of hydrocarbons and coal are rising faster than previously thought. For example, emissions from the oil industry in Alberta, Canada, were 25-50% higher than earlier estimates.

In civilized countries, carbon dioxide emissions in the last three to four years have become one of the main characteristics of the car. The irony is that there is only one way to reduce the amount of carbon dioxide escaping from the pipe - to curtail the engine's appetite. After all, the mass of CO2 spat out by a car and liters of fuel eaten directly depend on each other.

Therefore, detachments of minders and engineers of automobile companies are at the forefront in the war against a dangerous enemy. The main means of fighting for the purity of the exhaust have been known since the mid-90s of the last century: variable valve timing, variable-length intake ducts, lightweight parts and assemblies, not to mention various materials and technologies that reduce friction losses. In addition, engineers at Bosch, which manufactures fuel equipment for most European models, estimate that the interaction of a turbo (or mechanical supercharger) with direct injection alone reduces emissions by up to 4%. And if you take this couple and remove the same power from a smaller volume (the now popular downsizing principle), then emissions can be reduced by a third.

“If the car cannot smoke, then it cannot go,” he said happily the main character of the Czech cartoon "Mole in the City", plugging the exhaust pipes with sausages. Indeed, the cheapest and most effective way to reduce carbon dioxide emissions is to turn off the engine. Now electronics do it for the driver. For example, the "start-stop" system, which is no longer only equipped with expensive models, turns off the engine at traffic lights, reducing emissions by 4-8%. Various hybrid schemes make an even more tangible contribution - as much as 25% in certain driving modes. Finally, the engine can be partially shut off. Cutting off half the cylinders until recently was the prerogative of multi-cylinder V-engines, but such a system is beginning to be installed on more compact engines. For example, Volkswagen has equipped it with new turbocharged fours.

However, you can save fuel and reduce emissions by improving other indicators. Designers' calculations show that reducing the drag coefficient by only 0.02 saves 0.4 l / 100 km at a speed of 130 km / h. With regard to CO2, this is 3–6%. The same amount will be written off tires with reduced rolling resistance. It is not without reason that all models from economical lines like Mercedes-Benz's Blueffectives and Volkswagen's Blueffects are equipped with these.

As a result, the new generation of machines is 13-30% more environmentally friendly and more economical than its predecessors. At least that's what the manufacturers say. Cars with liter engines have already crossed or are close to the psychological level of CO2 emissions of 100 g / km. And this is without hybrid technologies that promise great benefits.

This medal also has an unattractive side: the consumer will have to pay for all the achievements. First, when buying, the manufacturer wants to return the amount spent on the development, implementation and production of all the know-how. Secondly, often during operation. Alas, the reliability is not the best strong point modern cars. But even medium-sized repairs sometimes hurt your pocket. Do those tirelessly tightening emission standards remember this?

NOT GASOLINE ONE

In terms of CO2 emissions, all automotive fuels are preferable to gasoline. Even more “dirty” (as many believe) diesel fuel: light turbodiesels, especially large ones, are 5–15% more restrained than gasoline engines of comparable power. But this is not a reason to call for an early dieselization. Otherwise, there will be problems with the sale of fuel, because when refining oil, it turns out about equal amount gasoline and diesel fuel. In addition, diesel fuel is ahead of the rest of the planet in soot emissions.

Alternative fuels are less generous in CO2 emissions (g / km) than the familiar gasoline. But each has both pros and cons. The German researchers took as a basis for the calculations an atmospheric engine with an average consumption of 7 l / 100 km:

Another alternative is biofuels. Think about it: an engine powered by biomethane emits about 30 times less CO2 than a gasoline engine ( ZR, 2012, No. 4 ). A significant advantage! However, mass use is held back by undeveloped infrastructure, and no one is in a hurry to invest in its development. In addition, biodiesel production is limited to the crop area where the feedstock is grown.

Finally, the most fashionable trend is the use of electricity. Most of all funds are directed here, but is it worth it? The generation of electrical energy endows nature with carbon dioxide two to three times more generously than all transport combined! Even a small "Smart" with an electric motor, if you calculate the harm from the electricity it consumes, emits 71 g / km of CO2. A lot, considering the size of the car! So it is perhaps too early to campaign for a massive and rapid transition to electric traction. At least until most of the energy comes from renewable sources like wind turbines or solar panels.

Approximate shares of CO2 emissions from various sources. They depend on the level of development of a particular country:

SUPERIOR SUPERVISION

In Europe, cars are allowed to emit 130 g / km of CO2 (average per model range for each manufacturer). The norm is valid until 2015, and by 2020 the threshold will be reduced to 95 g / km. However, the role of the state is not limited to the introduction of stricter environmental regulations. It should encourage citizens to buy new cars that emit significantly less harmful gases. For example, over 15 years, the BMW 7 Series with the same engine power has become a third more modest. Along with the stick that high taxes on old cars serve, there is the carrot: a government-backed recycling program.

In addition to much greater financial costs, another direction of the state's activity also requires the involvement of competent specialists - this is the planning of the road network. A car at cruising speed emits much less CO2 than a car pushing through many kilometers of traffic jams. Ideally, new routes should be laid in the early stages of development, but sometimes you have to fit a road into the existing infrastructure. And no matter how wild it sounds, the best way out for the environment can sometimes be deforestation for a new highway.

Fifty square meters forests neutralize carbon dioxide from the breath of one person. In a traffic jam on the same square, there are three passenger cars emitting carbon dioxide in the most uneconomical mode. It turns out that cutting down trees is sometimes a logical and reasonable way to reduce greenhouse gas emissions:

As you can see, there are many options for reducing this greenhouse gas emissions. It is important to choose solutions that are not only beautiful, but also truly effective. Only then will it be possible to save both money and health.