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SUMMARY

I. Introduction

This paper shows the National Greenhouse Gas Inventory of Emissions and Absorptions of the Republic of Cuba. It has been arranged within the framework of the scientific and technical program "Protection of the Environment and Sustainable Development in Cuba", coordinated by the Environment Agency of Cuba. This Inventory is also a part of the activities of the Project CC: TRAIN of the United Nations Development Program (UNDP). The project CC:TRAIN was financed by the Global Environmental Fund (GEF) and bilateral donors. The United Nations Institute for Training and Researches (UNITAR) implemented it.

The developing, periodical update, publishing as well as to make available to the Conference of Parties of national inventories of antropogenic emissions by the sources and absorption by sinks of all greenhouse gases (GHG) not controlled by the Montreal Protocol is one the commitments signed by all the Parties of the United Nations Framework Convention on Climatic Change (UNFCCC).

Cuba signed the UNFCCC during the Summit of the Earth held in Río de Janeiro, Brazil (June, 1992) and ratified it on January 5, 1994. It came into force for Cuba on April 5, 1994. Although in the country were worked on the issue of climatic change from several years before the Summit and the activities became more intense after the summit, it is around the end of 1996 that Cuba entered into a higher stage of work once it joined the Second Stage of the Program CC:TRAIN and created the National Team on Climatic Change.

In line with paragraph 1, article 12 of the UNFCC, Non-Annex I Parties shall present an Initial National Communication within a term of three years after the date on which Convention became into force for the Party of reference, or after such a Party has the required financial means for that end. One of the major elements of a National Communication is the National Greenhouse Gases Inventory.

The National GHG Inventory not only contributes to improve the estimates of global emissions but it also provides the basis for the implementation of national actions such as the projection of possible future emissions and the identification and assessment of strategies to mitigate the emissions.

Comparable methodologies shall be used to compile the inventory so that national results may be consistently compared. The Revised 1996 IPCC Guidelines (IPCC, OECD, IEA, 1997) for National Greenhouse Gas inventories are the approved by the Conference of Parties for this end.

Based on different criteria, the atmospheric gases most relevant for the climate have been selected to be treated in the inventories. For convenience, these gases are referred to as GHG although some of them are not. Consequently, they can be divided into:
 

Carbon Dioxide (CO2), Methane (CH4), Nitrous Oxide (N2O), Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs) and Sulphur Hexafluoride (SF6)
 


Carbon Monoxide (CO), Nitrogen Oxides (NOx), Non-Methane Volatile Organic Compounds and Sulphur Dioxide (SO2).

The importance of these gases lies on their role as precursors of Greenhouse Gas (GHG), modifiers of their concentrations in the atmosphere and precursors of aerosols such as the case of SO2.

II. National Greenhouse Gas Inventory of Emissions and Absorptions of the Republic of Cuba

A multidisciplinary team was created to prepare this inventory. This team is made up by three working groups coordinated by the Institute of Meteorology, which belongs to the Ministry of Science, Technology and Environment.

The inventory uses the following major categories of sources/sinks to report the emissions and constitute the modules for the monograph of the inventory:

Besides the previous modules, the inventory also has an introduction to the topic, an general summary and a module for the analysis of uncertainty. There are also references and annexes with the summary tables and the worksheets of the inventory.

For the calculation of emissions the Revised 1996 IPCC Guidelines (OECD-IEA, 1997) are mostly used, although for some sources, these are complemented by other recognized methodologies (U.S. EPA, 1995; CORINAIR, 1996; IAEA, 1999). The activity data used are those available in the country and were obtained from different sources, basically through from the National Statistics Office of the Economic and Planning Ministry.

Some reports of data published by the National Statistics Office and the CEE (CEE, 1991, ONE, 1998) are also used. Concerning the emissions factors, basically those provided by the Guidelines are used. However, for some of the sources, these factors were modified or adapted based on studies carried out in the country.

The year 1990 is the one used as a base. This is one of the years considered as an option to prepare the inventories. This year was selected for several practical reasons and availability of information. It provides a higher level of comparison when it comes to the results gathered. This is the year that has been more widely used as a base year by the Parties to the Convention. However, the base year for some calculations is just one year out of a number of years that is used to calculate a mean.

According to the request of the Guidelines, a complete inventory for 1990 is provided. Estimates are reported in gigagrams (Gg) of the pollutant: 1 Gg = 109 grams = 103 tons.

III. Obtained Results

Total Net Emissions

The total of net emissions (1) of Greenhouse Gas in Cuba for the base year 1990 was estimated in 13 656,75 Gg with the percentages shown in Fig. I by gas. As it may be observed, of the direct GHG, CO2 with 11 425,6 Gg represents 83.66% of net emissions followed by CH4 with 510,19 Gg (3,74%) and N2O with 56,3 Gg which represents 0,4% of the total).

Table I show a summary of total net emissions per gases and sectors and Figure II shows the contribution of each sector to emissions. The Energy Sector with
34 647.56 Gg provides the largest share of emissions while in the sector of Land- use Change and Forestry is produced a net absorption of 23 982,67 Gg . The growth of biomass in the forests and other kinds of woody vegetation is the only sink of carbon considered up to the moment in the Guidelines.

When dealing with absolute values, in the year 1990 there were 41 315,6 Gg of GHG as emissions and 27 658,89 as absorptions so there was a net emission of
13 656,71 Gg as previously pointed.
 
 


Fig. I. Percentage distribution of total net GHG emissions in Cuba.
Base Year 1990.

Table I. Total net GHG emissions (Gg) in Cuba. Base year 1990.

CO2 CH4 N2O NOx CO NMOVC SO2 Total
National total
11425.56 510.19 56.3 141.73 947.23 142.91 432.8 13656.75
Energy
33155.06 10.58 1.06 129.06 857.16 69.99 424.6 34647.5
Industrial Processes
2268.5   3.32 8.02 1.57 65.65 8.19 2355.26
Solvents
          7.26   7.26
Agriculture
  374.5 51.91 4.27 75.09     505.77
Land-use Change and Forestry.(1)
-23998 1.53 0.01 0.38 13.41     -23982.67
Wastes
123.58 NE 123.58
Memo (2)
 
International Bunkers
1143.98 0.05 0.02 15.61 15.46 2.15 11.074 1188.75
Biomass (3)
21380.83              

(1) Net absorption for CO2. (2) These are not included in the total for the nation.
(3) Top-down approach.  (4) Not estimated



Fig. II. Contribution of each sector to the total of GHG emissions and other gases of radiative
importance in Cuba. Year 1990. Net emissions 13 56,71 Gg.
Relative Contribution to Global Warming. Aggregate Emissions in Equivalents of CO2 (CO2-e)

The different gases previously analyzed do not contribute in the same way to the increase of the greenhouse effect. The Global Warming Potentials (GWP) are used to express GHG emissions on an equivalent basis that shows its contribution to the possible future warming. The GWP of a GHG is defined as the accumulative radiative forcing between the current moment and any temporal horizon selected, and it is caused by a unit of the mass of gas just emited and expressed relative to CO2 (Houghton et al., 1995). Its value depends so much on the persistence of the gas in the atmosphere as well as on its radiative forcing and it is calculated with the assistance of models coupled of the climate and atmospheric chemistry. They include direct effects of substances on radiation, mostly absorption of infrared radiation as well as indirect chemical effects on the balance of radiation.

The expressions of emissions in "CO2 equivalents" show the level of CO2 (CO2-e) that would cause the same level of radiative forcing as the mixture of this gas, other GHG and aerosols. Table II shows the contribution relative to radiative forcing of emissions calculated in the inventory for the major gases of direct greenhouse effect. In the calculation are use the GWP values for a temporal horizon of 100 year reported in the IPCC Second Assesment (IPCC, 1995).

As it may be observed for the temporal horizon above mentioned, if one considers absolute emissions without considering Land-Use Change and Forestry, the major radiative forcing comes from CO2 emissions with a relative contribution of 55,71% followed by CH4 with 16,85% and N2O 27,44%. If the analysis is based on net exhaust, N2O provides the major radiative forcing with 44,88%, followed by CO2 with 28,85% and very close to it CH4 with 27,06%.

It should be pointed that the report of aggregate emissions of GHG, expressed as its equivalent mass of CO2,that uses the potentials of global warming is not required by the Guides of the IPCC and it is optional in the case of the Guideliness of the Framework Convention of the United Nations on Climatic Change. However, the Kyoto Protocol requires that the Annex I Parties, report aggreagated  antropogenic emissions of "direct" Greenhouse  Gases expressed in equivalent of C02. Actually, there is a large uncertainty associated with the values selected by the IPCC for the potentials of global warming close to 35% although in the case of CH4 and N2H this uncertainty can be even higher.

Such uncertainties are caused, inter alia by the insufficiency of global coverage of monitoring stations where the behavior of the concentrations of CH4 and N2H in the atmosphere is monitored. This has caused frequent changes in the values appointed for the potentials of global warming. Such changes are important within the framework of emissions in developing countries, specially in the case of CH4. Because of the reasons previously stated, conclusions shown in Table II derived from the use of aggregate emissions expressed in the equivalent mass of CO2 should be assumed with caution.

Table II. Relative contribution of the major direct GHGs to the radiative forcing based on
the Global Warming Potentials. Base year, 1990. Aggregated emissions expressed in CO2-e.

Gas
Emission (Gg)
GWP

Temporal horizon 100 years

Relative Total
Relative Contribution (%)
Based on gross emissions (1)
CO2
35 423.56
1
35 423.56
55.71
CH4
510.19
21
10 713.99
16.85
N2O
56.3
310
17 453.0
27.44
AE
   
63 590.55
 
Based on net emissions (2)
CO2
11 425.56
1
11 425.56
28.85
CH4
510.19
21
10 713.99
27.06
N2O
56.3
310
17 453.0
44.08
AE
   
39 592.55
 

(1) Emissions and absorption of CO2 from the land –use change and forestry are not considerate
(2) Emissions and absorption of CO2 from the land –use change and forestry are considerate
AE = Aggregated emissions.

Following there is a summary of the estimates of emissions in each module of the inventory. There are brief comments on the results obtained.

Module 1. Energy

This module cover the estimates of greenhouse gases and SO2 derived from energy related activities. It is subdivided into two major categories: the combustion of fuels and fugitive emissions. Emissions from the energy sector were 34 647,6 Gg in 1990. Table III shows a summary of this sector divided by the major source categories..

Table III. Total GHG emissions from the energy module (Gg). Cuba. Base year: 1990.

CO2 CH4 N2O NOx CO NMVOC SO2
Total 33155.06 10.58 1.06 129.06 857.16 69.99 424.6
Fuel Combustion 33155.06 10.04 1.06 128.67 856.57 33.84 418.5
1 Energy Industries  12105.56 0.48 0.10 31.86 2.39 0.80 235.8
2Manufacturing Industries and Construction  9348.20 5.77 0.81 46.39 711.39 9.80 150.3
3 Transport 3550.87 0.31 0.05 38.38 95.06 18.57 16.4
4 Other Sectors (1) 4067.76 1.33 0.04 5.75 19.96 1.28 10.8
5 Others (2) 4082.67 2.15 0.06 6.29 27.77 3.39 5.2
Fugitive Emissions   0.54   0.39 0.59 36.15 6.09
1 Solid Fuel   NO          
2 Oil and Natural Gas  0.54 0.39 0.59 36.15 6.09

1) Commercial/ Institutional/Residential/ Agriculture/Forestry / Fishing.
2) Other sources not considered in other places. NO - Not occurring.

Fuel Combustion
 

CO2 Emissions. Reference Approach.

The calculation of emissions of CO2 was approached here based on the contents of carbon of fuels provided to the country. Such a content is taken as a whole. Emissions obtained with the reference approach (top-down) were 33 279.2 Gg. and they come by 97.7% from liquid fuels, 2.11% from solid fuels and 0.19% from gaseous fuels.

CO2 Emissions. Approach by Source Categories

This method deals with the calculation of emissions based on the contents of carbon from the fuels provided to the main activities of combustion - categories of sources. The division by sectors is in line with the need of that information for monitoring and the formulation f policies to reduce emissions. The emissions for the different fuels and for each of the main categories of source of the IPPC are calculated here. The Fig. III shows a summary of CO2 emissions obtained by this method (sectoral approach). They total 33 155,06 Gg. A slight difference of 0.37% may be observed between the two approaches (top-down and sectoral) in the estimate of CO2 emissions in this module.

     


    Fig. III. Emissions of CO2 by source categories based on fuel combustion. Cuba, Base year 1990.

    Non-CO2 from Fuel Combustion by Source Categories

The emissions of CH4, N2O, CO, NMVOCs and NOx are calculated here applying emissions factors to the statistics of annual fuel consumption organized by sectors of major activities. Emissions of SO2 based on additional hypothesis on the contents of sulfur in fuels are also calculated.

Fig. IV shows the percentage distribution of GHG emissions different from CO2 and SO2 from the fuel combustion. The largest share of this emissions belongs to carbon monoxide (CO) with 856,57 Gg and the rest represents nitrogen oxides with 126,66 Gg, NMVOCs with 33,84 Gg, methane (CH4) with 10,04 Gg and nitrous oxide (N2O) with 1,06 Gg.
 
 


Fig. IV. Percentage distribution of Non-CO2 and SO2 emissions caused by fuel combustion (Gg).
Cuba. Base year 1990.

Fugitive Emissions

All the emissions of methane from the production, processing, storage transport and use of oil and natural gas and non productive combustion are included in this category. The use of oil and gas and fuel byproducts to provide energy for internal use in the processing and transport in the production of energy is excluded. Generally, these emissions are low and in 1990 contributed with 0.54 Gg to the national total. Oil refining and the distribution of gas were the largest contributors.
  The emissions of Carbon Monoxide (CO), Nitrogen Oxides (NOx), Volatile Organic Compounds Different from Methane (NMVOCs) and Sulfur Dioxide (SO2) from oil refining are calculated under this category. The synthesis of petrochemical products is not included here. Fig. V shows the results obtained in this sector.


Fig.V. Emissions of ozone precursors of and SO2 from oil refining. Base year 1990.

Módule 2. Industrial Processes

Greenhouse gases from the industrial processes not related to energy are dealt with in this module. The processes of industrial production, which cause physical or chemical transformation of materials, are the major sources in this case. The estimates of emissions were made for four main source categories: mineral products, chemical industry, production of metals and other productions.

Table IV shows a summary of emissions for this module according to the category of sources and Fig. VI shows the percentage distribution of total emissions according to the category of sources, being the production of mineral products the largest contributor of emissions with 70.56%.

Table IV. Total emissions of GHG (Gg) from industrial processes by sources category . Base year 1990.

Category of Sources CO2 N2O NOx CO NMVOCs SO2
Mineral Products  1 605.91     0.0002 53.91 0.99
Chemical Industry 261.7 3.32 7.96 1.38 0.82 6.95
Production of Metals  400.89   0.01 0.003 0.01 0.01
Others     0.05 0.19 10.92 0.24
Total 2 268.5 3.32 8.02 1.57 65.66 8. 19

Fig. VI. Module Industrial Processes. Percentage distribution of GHG emissions by sectors (Gg).
Base Year 1990.

The major results for each of these sectors are the following:

Mineral Products

The production of mineral products emitted 1 660,80 Gg of greenhouse gases in 1990 and 90,69% of these are made up by CO2. Among the sources evaluated in this sector there is the production of cement. It contributes with 88,2% to the emissions caused by the production of minerals. As part of the calculations, the production of lime, the production and use of soda ash, as well as the asphalt roofing production, the road paving with asphalt and the production of glass were also included.

Chemical Industry

The manufacturing processes of the chemical industry are an important source of pollutants emissions to the atmosphere. In Cuba, the most important processes with a relative major share of GHG emissions are covered by the production of ammonia, nitric acid and sulfuric acid. There are other chemical processes with very low emissions if compared to the previous ones and they were not included in the calculations by be not had the corresponding emission factors or experimental measurements. During the year 1990 there was a total emission of 280,74 Gg of greenhouse gases in this processes and of these, 93.2 Gg were represented by CO2.

Metal Production

The analysis is based on the production of steel, which is one of the major sources in this sector. The production of aluminum is another important source contributing with a large share in the exhaust of CO2, precursors of SO2 and PFC but this process does not take place in Cuba. A total of 400,92 Gg were emitted and 99.99% of this figure is represented by CO2.

Other Productions

The emissions from the industry of pulp and paper as well as those from the food and alcoholic beverage productions are also included here. A total of 11,4 Gg of greenhouse gases were emitted as part of the manufacturing process of these products and of these gases 95.77% are represented by NMVOCs.

Module 3. Solvent and other Product Use

The emissions of volatile organic compound different from methane (NMVOCs) derived from a large variety of antropogenic processes of production and consumption are calculated in this module. The inventory covers the calculation of emissions from some major sectors such as the use of paints, the industry of graphic arts, the production of asphalt for roofs and the use of solvents for domestic use. Fig. VII shows a summary of NMVOCs emissions from the use of solvents in the year 1990. The summary is divided according to the category of source.

Fig. VII. Emissions of NMVOCs from the use of solvents by type or source.
Cuba. Base year 1990. Total emission 7,26 Gg

Use of Painting

It covers the use of protecting materials -whether liquid or in the form of powder- or for decoration on surfaces. These coatings include paintings, varnish and lacquer as solvents -generally organic- or paint diluted in water. The NMVOCs emission is caused by the evaporation of the organic solvent used as dissolvent and in cleaning activities. A total of 4,03 Gg of NMVOCs were emitted on account of these actions.

Industry of Graphic Arts

This category covers different industries like the printing of papers, books, journals, etc. The printing of products used for packing such as cardboard, plastics, metals, layers of cellulose and for decoration and other ends is also included. A total of 0,185 Gg of NMVOCs were emitted in 1990.

Polimerization and Stabilization of Asphaltic Materials for Roofing

This process implies blowing air through hot asphalt to rise the temperature under which it can be softened. Hot asphalt is oxidized by way of an exothermic reaction. Other characteristics of asphalt may also be changed in this way. The kind of crude oil used as well as the characteristics of asphalt may influence upon emissions. Normally, the more volatile crude oils cause the largest emissions. The amount of NMVOCs in this process is low and in the case of the year 1990 the figure amounted to 0,54 Gg.

Domestic use of Solvents

It covers the emissions of NMVOCs. This emission is caused by the use of different products by the people although there is a share that is emitted by the industry. The use of cosmetics and products for personal hygiene and others for the preservation and improvement of the conditions of cars, buildings, etc are some of the products included in the list. Some pesticides and insecticides used domestically may also be included although the largest share of them is manufactured for the agriculture. Emissions take place due to the evaporation of Volatile Organic Compounds of the products while being used. A total of 2,53 Gg of NMVOCs were emitted on account of this line of products during the year 1990.

Module 4. Agriculture

The emission of greenhouse gases from five sources is considered here:

Table V shows a summary of GHG emissions from the agricultural activities. Fig. VIII shows the percentage distribution of the emissions of each of theses gases in this module.

Table V. Total emissions of GHG from Agriculture (Gg). Cuba. Base year 1990.

  CH4 N2O NOx CO
Total 374.51 51.91 4.27 75.09
Enteric fermentation 346.44      
Manure management 17.85 0.0001    
Rise cultivation 6.64      
Agricultural soils   51.78    
Burning of residues 3.58 0.13 4.27 75.09

Fig. VIII. Percentage distribution of GHG emissions from Agriculture (Gg).
Cuba. Base year 1990

The summary of results is as follows:

Domestic Livestock

This section deals with the emission of methane from enteric fermentation and manure management. According to the results of calculations, enteric fermentation produced 346,44 Gg being the bovine the largest contributors with (94.94%) and of these, those devoted to the production of milk are the largest contributors. In the case of Cuba it was observed that the second largest contributors were the horses during the term analyzed.

Methane may be emited from excreta of domestic animals, being the largest emissions in the group of bovine and pigs. Methane is produce by decomposition of manure mostly under anaerobic conditions. The results of calculations of emissions caused by the management of manure contribute with a total of 17,85 Gg and 44,54% comes from pigs.

Methane Emissions From Rice Cultivation

The cultivation of rice has been increasing after 1959 together with agricultural and technical measures to improve efficiency. When this inventory was made up there was an area of 162 135,6 ha under cultivation. During the term of rice cultivation methane is emitted as a result of anaerobic decomposition of organic matter under the waters used for flooding. Microorganisms in the soil are responsible for this decomposition. Fig. IX shows the results of emission for the base year.


Fig. IX. Emissions of CH4 from the rice cultivation according to the period of plantation (Gg).
Cuba. Base year 1990. Total emission 6,64 Gg.

Emissions of Greenhouse Gases From  Prescribed Burning of Savannas and Pastures.

Actually, this is not a standard practice in Cuba because it is officially prohibited. In this case, one can calculate emissions when there are incidental fires but this is analyzed in another module of the inventory.

Field Burning of Agricultural Residues

This section deals with the burning of sugar cane fields because of different reasons: harvesting, removal of old fields and so on. According to the Guideliness, this section includes the emission of GHG different from CO2 since is assumed that the carbon released during burning is reabsorbed during the growth of the plants in the next vegetative period.. The emission of these gases resulted in a total of 83,07 Gg and of these, 90.39% represent CO (75,09Gg), 5.14% represent NOx (4,25 Gg), 4,31% represent CH4 (3,58 Gg) and 0.16% represent N2O (0,13 Gg)

Emissions of Greenhouse Gases from Agricultural Soils

It is accepted that agricultural soils are an important emission source of gases with nitrogen, such as N2O. Direct emissions of N2O from land devoted to agriculture, direct emissions of N2O from lands devoted to cattle rising and indirect emissions of N2O from nitrogen used in agriculture are calculated under this section. Table VI shows the results obtained.

Table VI. Total N2O emissions from agricultural soil (Gg). Cuba. Base year 1990.

Concept of emission
Total emission of N2O
(Gg N2O / year)
% of total
Agricultural fields
33.41
64.52 %
Land used for grazing animals
5.86
11.32 %
Deposition
1.97
3.80 %
Lixiviation
10.54
20.36 %
Total
51.78
100 %

Module 5. Land-Use Change and Foresty

This module attaches priority to the calculation of emissions arising from the change in the use of land and forestry. These emissions come from the actions in three lines, which are sources or sinks of CO2. Globally, these actions are recognized as the most important concerning the use of land and the management practices that lead to emissions and absorption of CO2.

The immediate release of non- CO2 trace gases-CH4, CO, N2O and NOx- caused by forest grassland conversion by means of fire is also calculated. In Table VII there is a summary that shows the emissions and absorption of GHG in this module. The emission and absorption of CO2 caused by changes in the use of land and silviculture are shown in Fig. X.

During the base year, there was an emissions of 3 660,88 Gg of CO2 and an absorption of 27 658,88 Gg of CO2.This results in a net absorption of 23 998 Gg of CO2.

Table VII. Emissions and absorptions of GHG caused by Land Use Change and Foresty (Gg).
Cuba. Base year 1990.

 
CO2

Emissions

CO2

Absorptions

CH4
N2O
NOx
CO
Total (1)  
23 998.0 (1)
1.53
0.01
0.38
13.41
Changes in forest and other woody biomass stock
376.35
27 658.88
       
Forest and grassland conversion
3 242.03
 
1.53
0.01
0.38
13.41
Abandonment of managed lands  
NO
       
Emissions and absorptions of CO2 from the soil
42.5
         
NO- Not occurring; 1) Net


Fig. X. Emissions and absorptions of CO2 from the land-use change and foresty.
Cuba. Base year 1990. Net absorption 23.998.0 Gg.

Following, there is a summary of each field analyzed:

Changes of the Biomass in the Forest and other Woody Biomass Stocks.

The emission and removal of carbon and carbon dioxide following changes in the biomass of woods and other types of woody vegetation caused by human actions are estimated under this point.

For the calculation of the net absorption of CO2 you have to estimate the annual increase of biomass in the plantations, woods cut down or used in some other form, the growth of trees in the cities, farms and urban areas as well as the remaining woody vegetation. You also have to estimate the amount of wood used as firewood as well as that used for timber and other uses. Next, net absorption of carbon by these sources is made.

The following step for the calculation of exhaust or removal or carbon is related to calculation of the quantity of biomass grown. In this case, you start from the data gathered on the commercial harvest of wood, the total use of firewood including wood use fort the production of charcoal and other uses of wood. By considering the data on the total increase in the absorption of carbon ant the annual exhaust of carbon, the results obtained show that there was a net absorption of
7 440,69 kt C i.e., 27 282.53 Gg CO2 (Table VIII).

Table VIII. Yearly absorption of CO2 caused by changes in the forest and other types of woody vegetation .
Cuba. Base year, 1990.

Yearly absorption of carbon 
(kt C)
Yearly release of carbon
(kt C)
Net Absorption of carbon 
(kt C)
Net absorption of CO2
(Gg CO2)
7 543.33
102.64
7 440.69
27 282.53

CO2 Emissions from Forest and Grassland Conversion

The changes of forest and grasslands turned into lands for cultivation or permanent pasture areas takes place mostly in the tropics. Tropical forest clearing is usually accomplished by cutting undergrowth and felling trees followed by burning biomass on site or as fuelwood. By this process some of the biomass is burned while some remains on the ground where it decays slowly (usually over a period of ten years in the tropics).. Of the burned material, a small fraction (5-10 per cent) is converted to charcoal which resist decay for 100 years or more, and the remaninder is released instantaneously into the atmosphere.

For the calculation of the emissions of CO2 derived from the changes of forest and grassland areas three types of calculation are used: a) CO2 emitted while burning the aerial biomass on-site or off-site -immediate emissions that takes place within the year of changes, b) CO2 released during decomposition of the aerial biomass - differed emissions that takes place within a ten year term, c) CO2 released by the soil. More data are needed for the calculation such as the biomass existing before and after the change (both in tons of dry matter per ha.).

Table IX shows the estimation of the total CO2 emissions by the conversion of forest and grassland areas. It is shown that emissions differed by decomposition contribute 26.65% in the release of carbon.

Table IX. Emissions of CO2 from forest and grassland conversion. Cuba. Base year 1990.

Immediate release caused by combustion 
(kt C)
Differed emissions caused by decomposition 
(kt C) (average in 10 years)
Yearly total of carbon released

(kt C)

Yearly total of CO2
Released

(Gg CO2 )

648.54
235.65
884.19
3 242.03

On-site Burning of Forests: Emissions of Non-CO2Trace Gases

Burning the biomass to obtain energy as well as burning savannas and agricultural wastes is a significant source of CH4, N2H, CO, and NOx. The emissions of gases different from CO2 caused by on site burning of forest are calculated under this section. The total emissions of GHG contributed 15,33 Gg and of these, CO represents 87.48% (Fig. XI).

Fig.XI. Emissions of non-CO2 trace gases derived from on site burning of forests (Gg). Cuba.
Base year. Total emissions 15.33 Gg.

Abandonment of Manged Lands

Net CO2 removal in the biomass accumulation resulting from the abandonment of managed lands is dealt with in this section. This removal is not estimated in the inventory because it is not a practice to abandon lands of cultivation in Cuba. According to statistics of ONE, data on idle lands were registered. These lands were not rated under this category for a term of more than two years during the last two decades.

CO2 Emissions or Uptake by Soil from Land-use Change and Management

The methodology includes the estimation of the net emissions of CO2 -sources and sinks- in three processes: 1) changes in carbon stored in the soils and litter of mineral soils due to changes ib land-use practices, 2) CO2 emissions from organic soils converted to agricultural or plantation forestry, and 3) CO2 emissions from liming of agricultural soils.

The inventory could not cover estimations concerning the changes of carbon in mineral soils because there were no suitable maps of land use with the adequate scales. They did not cover the information of the years requested by the inventory to make the calculations (1990 and 1970). The implementation of actions to carry out this point called for finances, which were not available. These funds were needed to make or use aerial or cosmic photos.

Concerning emissions from organic soils changed for use in agriculture or plantations, they are not considered important for the country and was not included in the estimates. Updated information on this point was neither available.

The estimation of the CO2 emissions from liming was based on statistics on the total use of restorative agents in agricultural lands. The estimation of total net exhausts of CO2 in agricultural soils gave 42,5 Gg CO2.

Module 6. Wastes

This module deals with the estimation of methane emissions (CH4) from solid waste disposal sites and wastewater handling as well as the emissions of nitrous oxide (N2O) from human sewage.

Methane is the most important GHG produced by the disposal and treatment of wastes, specially by way of anaerobic systems used for the management of biodegradative wastes resulting of human activity: sanitary landfilling and the treatment of wastewaters. Table X shows a summary of CH4 emissions in the module of wastes, they contribute with a total of 123,58 Gg. Fig. XII shows the percentage distribution of total emissions of CH4 from the wastes.

Table X. Emissions of CH4 from the wastes (Gg). Cuba. Base year 1990.

 
CH4
N20
Total
123.58
NE
Land disposal of solid waste
71.09
 
Handling of commercial and domestic 
wastewaters
6.54
 
Handling of industrial effluents
45.95
 
Human sewage  
NE

NE: Not estimated
 
 
 


Fig. XII. Percentage distribution of emissions of CH4 from wastes. Cuba. Base year 1990.

Following, there is a summary of emissions per each category of source.

Methane (CH4) Emissions from Solid Waste Disposal Sites

This section dealt with the estimation of methane emissions from sites of solid waste disposal. These sites are divides in the Guideliness into "controlled" and "not controlled" depending on the extent and type of active control in the site. A yearly emissions of 71,09 Gg was estimated under this category for 1990.

Methane (CH4) Emissions from Wastewater Management

The treatment of wastewaters with high contents of organic matter including domestic and commercial wastewaters and some industrial effluents-may give rise to significant amounts of methane. The inventory separately calculates emissions caused by the treatment of the two main types of wastewaters; they are:

The major factor that determines the potential for the generation of methane in wastewaters is the amount of organic matter they contain. In the case of wastewaters and domestic and commercial sludges this is in line with the Biochemical Demand of Oxygen while in the case of industrial effluents the Chemical Demand of Oxygen is used. These category of sources emitted 6,54 Gg of CH4 in 1990 as a result of the treatment of domestic and commercial wastewaters and 45,95 Gg of CH4 by the treatment of industrial effluents.

IV. Per capita Emissions of CO2 and Carbon

This section provides a bit of information on per capita emissions of CO2 gathered in the national inventory by means of two different ways of estimation. Special attention should be considered when using or comparing data on per capita emissions among different countries because there has to be certainty that they were obtained using the same budgets for calculation. In many of the reports published there are significant differences because some of the estimates come from considering net emissions, taking into account emissions and absorption from the module "Land-Use Change and Forestry". Other reports do not consider this module or do not consider the absorption that occurs in it.

In some of the issues published, estimates of per capita emissions come from data based only on the emissions of energy and some industrial processes, specially the production of cement. As a way to shed more light on this point Fig. XIII shows the results obtained from net emissions considering the emissions and absorption of the module "Change in the Use of Land and Silviculture" as well as absolute emissions-without considering the module just mentioned. As it may be observed, results from per capita emissions are significantly different in dependence of the form of calculation. For the case of CO2 Cuba presented a per capita emissions of
3,31 t CO2/inhabitant (0,90 t C/inhabitant) for the base year, this without considering the module of change in the use of land and silviculture, and
1,07 t CO2/inhabitant(0,29 t C/inhabitant) when the module is put to consideration.
 
 


Fig. XIII. Percapita emissions of CO2 and Carbon in Cuba. Base year 1990.


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