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Moscow Biosphere Model

A System of Models of the Global Biosphere Cycles of A.M. Tarko

Global Spatial Model of Carbon Dioxide Cycle in Terrestrial Ecosystems

1. Description of the Model
2. Pre-industrial State of Biosphere
3. Biosphere Dynamics under Impact of Industrial CO2 Emissions, Deforestation and Soil Erosion
4. Zonal Distribution of CO2 absorption during industrial period
5. Consequences of Global Warming for Russia
6. Carbon Dioxide Budget of Countries
    Form to Download Data of CO2 Budget of the Countries
7. Carbon Dioxide Budget of Biosphere
8. Estimation of performance Kyoto protocol to the UN Framework Convention on climate change
9. Application the Control Theory in the Modeling
10. Final Remarks

Investigation of the global carbon cycle in the biosphere is important. On the one hand, carbon is a component of live and dead organic matter of the biosphere and hence the  indicator of ecological processes. On the other hand, it is presented in the atmosphere as carbon dioxide which defines the greenhouse effect and is a factor influencing the climate of the planet. The next impotence is the nitrogen cycle.
     A,M. Tarko developed system of models of global biogeochemical cycles in the biosphere including zero dimensional models of carbon and nitrogen cycle, and also spatial models of carbon cycle with a geographical grid 4x5 and 0.5x0.5o. The results of modeling biosphere dynamics in which the basic attention is given to the spatial cycle of carbon in the "Atmosphere - Terrestrial Plants - Soil" system are presented here. A simple carbon  cycle  model in the "Atmosphere - Ocean" system is added for full description the global cycle. The aim of modeling is to provide forecasts of atmospheric CO2 dynamics, to calculate CO2 parameters for the biosphere as a whole as well as for the individual countries and their ecosystems, and also to investigate the global role of terrestrial ecosystems in the compensation the anthropogenic impacts.

1. Description of the model

     In the model all land territory is divided to into cells of the size 0.5x0.5o of a geographical grid. It is supposed that in each cell there is a vegetation of one type according to the chosen classification. Two kinds of classification of types are used: 1. N.I. Bazilevich and L.E. Rodin and 2. J.S. Olson. The model is described by system of ordinary nonlinear differential equations. The model variables are quantities of carbon in the atmosphere, in live plants, and in soil humus in each cell. A time unit accepted in the model is one year.
     We consider that annual production of vegetation in each cell depends on atmospheric CO2 concentration, on temperature and precipitation in a given cell and does not depend on the ecosystem type. Three kinds of annual production dependencies were applied. The first one (A.M. Tarko) expresses in a tabulated form the dependence of annual production on temperature and precipitation. The next is the dependence of  H. Leith, the third is the dependence of M.V. Kuznetsova.
    The dependence of humus decomposition rate on temperature and precipitation in a given cell was also taken into account.
     Annual air temperature and precipitation characterize the climate in a given cell. Air CO2 concentration is considered to be equal in all the cells. The values of temperature and precipitation for each cell depending on atmospheric CO2 concentration (the greenhouse effect) are taken from the calculations at General Circulation Models (GCM).
     We assume that in the absence of anthropogenic CO2 emissions to the atmosphere the quantity of carbon in the biosphere is constant. Prior to the beginning of anthropogenic influences the system was in a steady state (usually 1860 is accepted as the year when the industrial era began).
     Dividing the territory into cells allowed allocating all countries of the world with size larger than 50x50 km.
    A computer program complex was developed to make calculations on the model. It works under the control of Windows 95/98/NT.


2. Pre-industrial State of the biosphere

      Computer map of annual production of the world vegetation at its pre-industrial state is shown below. The map is based on the annual production dependence of A.M. Tarko.

Computer map of annual production, kg C/(m2 yr)


 Computer map of humus at the pre-industrial state is shown below. Humus values calculations are based on the statistical estimation the dependence on temperature and precipitation.

 Computer map of soil humus, kg C/m2

3. Biosphere Dynamics under the Impact of Industrial CO2 Emissions,
Deforestation, and Soil Erosion

       We take into consideration the following anthropogenic impacts on the biosphere resulting in CO2 growth in atmosphere: fossil fuel burning (industrial releases), cutting down the forests, soil erosion resulting from wrong land use.
     Dynamics of the biosphere during 1860-2050 was simulated. Let us see the following scenario. The anthropogenic CO2 input to the atmosphere is a result of industrial releases, deforestation, and soil erosion. After 1996, the industrial emissions grew at the same rate as during the previous decade.
     The main effect of deforestation takes place in tropical forests. According to the scenario during 1950-2050 there is a deforestation and subsequent destruction of tropical forests. During this period, tropical forests  decreases each year by 0.6%.
     The soil erosion begins in 1860 and increases by 0.15 % per year. The ecosystem types are set where erosion takes place.
     Calculated dynamics of biosphere parameters is shown in a figure. Atmospheric CO2 quantity, annual production of plants, and plants biomass are increasing. The humus quantity is decreasing for a long time . Then, because of the annual production growth resulting from CO2 concentration and temperature increase, humus also begins to increase. Animated maps of plants and humus (see below) show spatial distribution of biosphere dynamics. Both the biosphere and ocean absorb about 50% of industrial releases of carbon dioxide. So anthropogenic actions are partly compensated and biosphere controls its stability. Problem of biosphere stability is considered from the point of view of  Le Chatellier principle: how does biosphere weaken anthropogenic impacts.

Dynamics, 7 kb

Calculation of dynamics of relative values of carbon in an the atmosphere,
in plants biomass, and in soil humus in 1860-2050

     Animated maps of plants biomass and humus changes  in 1860-2050 are shown below.

Animated map of changes of plants carbon, 115 kb

Animated map of plants biomass changes in 1860-2050

Min Max
Color for positive changes ____ ____
Color for negative changes ____ ____
No change ____

Animated map  humus carbon changes, 87 kb.

 Animated map of soil humus changes in 1860-2050

Min Max
Color for positive changes ____ ____
Color for negative changes ____ ____
No change ____

4. Zonal Distribution of CO2 Absorption during Industrial Period

     Consideration of the zonal distribution of CO2 exchange between the terrestrial ecosystems and the atmosphere during the industrial period shows that ecosystems of middle and high latitudes of the Northern hemisphere absorbed CO2 and ecosystems in the equatorial zone  released CO2 . The greatest absorption occurred in middle latitudes of the Northern hemisphere where plentiful forest ecosystems are concentrated. Move from the middle latitudes to the equator, the closer the ecosystem or the country to are to the equator, the lesser is the degree of CO2 absorbing. And ecosystems of the equatorial zone  were CO2 sinks. All ecosystems for this period absorbed more CO2 than they released.

Zonal absorption, 11 kb.

 Zonal distribution of CO2 absorption in 1860-1995 (Gt C/grad.).

5. Consequences of the Global Warming for Russia

     The whole territory of Russia during 1860-1995 was a CO2 sink though some ecosystems released CO2. Forest ecosystems were most powerful CO2 absorbers. Grasslands were CO2 sinks but at some territories were sources. Phytomass was increased at all ecosystem types. Humus decreased at some grassland ecosystems. Calculations show that now and in a future at the Russian territory it will be increasing the annual plants production and phytomass. Russian territory will absorb CO2 emissions. Quantity of humus will be mainly increased. But at some territories which allocated at agricultural zones mainly of southern regions humus will be decreased (see animated map of humus changes).

6. Carbon Dioxide Budget of Countries in 1995

      A comparison of carbon budget of ecosystems in countries which are the greatest CO2 "producers" (annual production minus humus decomposition, minus deforestation, minus soil erosion) and the appropriate industrial releases in 1995 are shown in a figure. That year ecosystems of the whole the world and in each of the analyzed countries absorbed CO2 . The greatest industrial emissions were from territory of USA, China and Russia. The greatest CO2 absorption occurred in territories of Russia, Canada and the USA. In the majority of the countries industrial emissions exceeded ecosystem absorption. The exceptions were Canada, Australia, and Brazil where ecosystem CO2 absorption was more than industrial releases. It could be due to the rather large territory of the country and relatively small industrial releases.

Countries absorption and releases, 19 kb

Comparison of carbon absorption by ecosystems of the countries and industrial releases in 1995 (Gt C/ year)

Form to Download Data of CO2 Budget of the Countries


                Here you can download global data of CO2 data
of all the world countries

You can also send a message to the author 


To download data: CO2 budget, industrial emissions,
and annual CO2  absorption by terrestrial ecosystems
of the world countries in 2006


To thank A.M. Tarko for the data,
to suggest cooperation, to put questions

7. Carbon Dioxide Budget of Biosphere

 Calculations show that the CO2 flows balance of in the world in 1995 was as follows.

Industrial releases -                                6.41 Gt C/ year,
Deforestation -                                      1.08 Gt C/ year,
Soil erosion -                                        0.91 Gt C/ year,
Absorption by terrestrial ecosystems -   4.05 Gt C/ year,
Absorption by ocean -                          1.05 Gt C/ year,
Remains in atmosphere -                       3.30 Gt C/ year.
     Last figure of balance indicates that 51% of industrial CO2 emissions remains in the atmosphere. It corresponds to the data of measurements (Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, USA).

8. Estimation of performance of the Kyoto protocol to the UN
Framework Convention on climate change

      In accordance to the Kyoto protocol (1997) to the UN Framework Convention on climate change all the countries should reduce the emissions of  greenhouse gases by 2010  to a level of industrial CO2 emissions in 1990. We will consider the effects of various restrictions on reduction of CO2 emissions. The following scenarios were considered: 1. Above mentioned scenario of anthropogenic influences. 2. Scenario 1, but, after 2020, the industrial CO2 emissions become constant and equal to the value which was in 1990. 3. Scenario 1, but after 2010 industrial CO2 emissions become constant and equal to the value in 1990 (it corresponds to the Kyoto protocol). 4. Scenario 1, but after 2000 industrial CO2 emissions become constant and equal to the value in 1990 5. Scenario 1, but after 2000 industrial CO2 emissions stop. 6. Scenario 1, but after 1990 deforestation and erosion stop.

Kyoto etc. scenarios, 7 kb

Results of calculation the Kyoto protocol scenario realization and other scenarios of CO2 emissions reduction.
Dynamics of relative values of carbon quantity in atmosphere are given

     We see that emissions restrictions are effective. According to scenario 1 CO2 concentration in atmosphere will be raised by 1.82 times by 2050 in comparison with 1860. According to scenarios 2, 3, and 4 increases of CO2 concentration will be significantly less: the CO2 growth will be 1.56, 1.47 and 1.42 times. It is obviously that the delay of beginning to implement the Kyoto protocol for 10 years does not result in significant change in 2050.
     The termination of deforestation and soil erosion does not lead to significant effect. CO2 growth reduction in this case is the least in comparison with other scenarios. The effect of reduction of deforestation and erosion gives weaker effect than reduction of industrial emissions. Total termination of emissions will result in CO2 decrease in the atmosphere.

9. Application the Control Theory in the Modeling

     Investigating the anthropogenic influences on the biosphere, it is important to establish not only what consequences of this or that economic strategy will be, but also what will be "a price" if we want to provide accepted values of biosphere parameters. Let us consider a task to set constant level of atmospheric CO2 after a given year. We are to determine what values of CO2 industrial emissions must be set to provide steady state of the atmospheric CO2. This was done using  the control theory methods . Results of calculation show that in order to provide constant level of CO2 in the atmosphere it is necessary to significantly decrease amount of emissions.

Control, 8 kb

Industrial releases at which the CO2 concentration in atmosphere remains constant after the given year (Gt C/ year)

Final remarks

      The models of global biosphere processes can be compared with some kind of "universal recipient", since they combine the approaches of many sciences: physics, chemistry, ecology, soil science, geography, geochemistry, climatology, economy etc. However these models are far from being "universal donor ". In other sciences, the amount of consumers of global modeling results it is small. Results received by using the global models enrich a science but practical application of global models can be found among the decision-makers. Application of the results of modeling is also possible in economic and social sciences. So, V.S. Golubev (Institute of  Lithosphere, Russian Academy of Sciences) used the biosphere parameters calculated here to investigated indices of social and natural development of various countries.

 Copyright c A.M. Tarko, 1999, 2000, 2007

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