I. Introduction
The National Inventory on Greenhouse Gas (GHG) Emissions and Removals of the Republic of Cuba corresponding to 1994 is presented. It constitutes the continuation of the estimate of the GHG emissions of the country, which had been started with the elaboration of the inventory for the baseline year 1990 that ended in 1999 (CITMA-CCTRAIN, 1999).
This inventory has been carried out within the framework of the Scientific-Technical Branch Program "Protection of Cuban Environment and Sustainable Development" coordinated by the Environmental Agency of Cuba, and also as part of the activities of the CUB-98-G31 Project: "Enabling Activity so that Cuba Elaborates its National Communication to the United Nations Framework Convention on Climate Change", with financing from the Global Environment Facility (GEF) and implemented by the UNDP.
The preparation, periodic updating, publication and transmission to the Conference of the Parties of national inventories of the anthropic emissions by the sources and of the removals by the sinks of all Greenhouse Gases (GHG), not controlled by the Protocol of Montreal, is one of the commitments contracted by all the Parties to the United Nations Framework Convention on Climate Change (UNFCCC). Cuba signed the UNFCCC during the Summit of the Earth in Rio de Janeiro, Brazil (June 1992), and ratified it on January 5, 1994, becoming effective for the country on April 5, 1994.
In accordance with article 12 paragraph 1 of the UNFCCC, each non-Annex 1 Party will present an Initial National Communication within the three-year term since the Convention became effective for that Party, if it has the necessary financial resources for that purpose. One of the fundamental components of the National Communication is the National Inventory of Greenhouse Gases.
The National Inventory of GHG not only contributes to improve the estimates of global emissions but also it provides the foundation for the execution of different actions in the country, like the projection of probable emissions in the future as well as the identification and evaluation of emission mitigation strategies.
Comparable methodologies should be used when compiling the inventory so that national results can be consistently compared. The Revised Guides of 1996 IPCC (IPCC, OECD, IEA, 1997) for National Inventories of Greenhouse Gases are those approved by the Conference of the Parties for this objective.
Based on diverse approaches, the atmospheric gases of more relevance for climate have been selected for their analysis in the inventories. For convenience, all are generically referred as GHG, although some of them are not as such. Therefore, they can be subdivided in:
Greenhouse Gases of Direct Effect
Carbon Dioxide (CO2), Methane (CH4), Nitrous oxide (N2O), Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs) and Sulfur Hexafluoride (SF6).
Other Gases of Radiative and Photochemical Importance
Carbon Monoxide (CO), Nitrogen Oxides (NOx), Non-Methane Volatile Organic Compounds (NMVOC) and Sulfur Dioxide (SO2)
The importance of these other gases is given by their role as precursors of Greenhouse Gases (GHG), modifiers of GHG concentrations in the atmosphere or precursors of aerosols –as in the case of SO2.
II. National Inventory of Greenhouse Gas Emissions and Removals of the Republic of Cuba. Year 1994
National System for the Calculation of Emissions
For this inventory it was employed the system and the capacity created starting from the preparation of 1990 Inventory, which is based on the work of a multidisciplinary technical team with three working groups coordinated by the Institute of Meteorology, belonging to the Ministry of Science, Technology and Environment.
The first group, mainly constituted by experts in pollution, atmospheric chemistry and climate from the Institute of Meteorology, assumed the methodological activities, calculations of emissions and uncertainties, writing of the chapters and elaboration of the inventory.
The second group, constituted by experts from the National Office of Statistics, assumed the task of the reception of most of the activity data necessary for the elaboration of the inventory. Experts in Statistics from the different sectors involved in the inventory participated in this group.
The third working group is constituted by experts from different bodies and institutions linked to the different modules of the inventory, who participate not only providing specialized information of their sectors but also assuming the estimate of emissions in several activities.
The following main categories of sources/sinks are used in the inventory
to report emissions and constitute modules within the monograph of the
inventory.
The Revised Guides of the IPCC 1996 are used for the estimate of emissions (IPCC-OECD-IEA, 1997). The activity data used are those available in the country and were received from different sources, fundamentally through the National Office of Statistics (NOS) of the Ministry of Economy and Planning. Some of the data reports published by the NOS are also used (NOS 1998; 1999). Regarding the emission factors, basically those provided by the Guides have been used.
The selected year is one of those established as option for the elaboration of inventories. Notwithstanding, for some calculations, the year is simply one of a number of years whose average needs to be calculated. As requested in the Guides, all estimates are reported in gigagrams (Gg) of the pollutant: 1 Gg = 109 grams = 103 tons.
III. Results Obtained in 1994: Comparison with the Baseline Year 1990
Gross emissions
Table I shows a summary of the gross emissions of GHG obtained for Cuba in 1990 and 1994. The reductions in the emissions observed between these two years are also indicated. The total gross emissions of GHG in 1990 was 41 314,83 Gg and in 1994; 26 045,76 Gg for a decrease of 36.96% between these two years. In both years, CO2 has the greatest contributions to the emissions with 94,6% in 1990, and 94,74% in 1994. In 1990, CH4 contributed a 1,23%, and 1,7% in 1994; and the N2O contribution was 0,14% in 1990, and 0,06% in 1994.
Table I. Gross emissions (1) of GHG (in Gg). Cuba, years 1990 and 1994.
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1) Total gross emissions, including the emissions of the
Land Use Change and Forestry module.
2) % of decrease in the 1994 emissions in relation to
those of 1990.
As it is observed in the table, in the volume of emissions, the most important decrease corresponded to CO2 with 14 410,63 Gg, which was mainly motivated by the reductions experienced in the Energy and Industrial Processes sectors. In other gases like N2O, NOx, CO and NMVOC, although the reductions in volume of emissions are less relevant, they presented high percentages of decrease in the emissions in relation to 1990. In the specific case of N2O, the decrease observed in the use of synthetic fertilizers exerted a marked influence in this situation.
Net emissions
The national total of net emissions (1) of GHG in Cuba was estimated in 13 656,75 Gg for the baseline year 1990. Of the GHG of direct effect, CO2 with 11 425,6 Gg represents 83.66% of the net emissions, followed by CH4 with 510,19 Gg (3.74%), and N2O; 56,3 Gg, for 0,40% of the total. In 1994, on the contrary, a net removal of 2 794,89 Gg of GHG took place. This removal was caused by the combination of the increase in CO2 removals in the Land Use Change and Forestry sector, with an important reduction in gas emissions in the Energy sector. Likewise, reductions in the emissions were also observed in other sectors and gases.
Tables II and III present a summary of the total GHG net emissions/removals by gases and sectors; and Fig. I shows each sector’s contribution to the emissions.
As it is observed, in 1990 the Energy Sector contributed most of the
emissions with 34 647,55 Gg, while in the Land Use Change and Forestry
Sector a net
removal (1) of 23 982,67 Gg took place. Moreover, in 1994,
in spite of the reduction observed in the emissions, the Energy Sector
with 22 261,54 Gg made the largest contribution, while in the Land Use
Change and Forestry Sector there was a net removal (1) of 26
469,6 Gg– a little higher than that observed in 1990.
The reductions observed in the emissions, starting from 1990, are a consequence of the marked economic crisis suffered by the country, due to the combined effect of the disappearance of the main links and commercial conditions that Cuba had sustained with the East European countries for several years, and the increase of the commercial economic blockade imposed by the U.S. on our country. Although the decrease in terms of the Gross Domestic Product reached 35% in these years, the production in general decayed in more than 45%, affecting in a widespread manner the economic and social activities, and especially main economic lines such as the sugar industry. Sectors of great importance in GHG emissions were also affected, like electricity generation, steel industry, nickel mining and processing industry, as well as the industry of construction materials, the transportation and agricultural activities.
Due to the lack of information, some few categories of sources included in the inventory of the baseline year 1990 could not be considered in the inventory corresponding to 1994. Nevertheless, since those categories contribute low emissions, their non-inclusion does not have a decisive role in the decreases observed between the two mentioned years. Such is the case of the emissions of forest fires by anthropic causes that are analyzed in the inventory as ‘burning in the site’ and that could not be estimated in 1994. This diminishes in a certain percent the emissions of CO2 and other GHG in 1994, but it is not the fundamental cause of the remarkable reduction observed.
Table II. Total Net Emissions and Removals of GHG (Gg). Cuba, 1990.
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NATIONAL TOTAL | 11425.56 | 510.19 | 56.3 | 141.73 | 947.23 | 142.9 | 432.84 |
ENERGY | 33155.06 | 10.58 | 1.06 | 129.06 | 857.16 | 69.99 | 424.65 |
A Burning of Fuels (reference) | 33279.2 | ||||||
A Burning of Fuels (sectoral) | 33155.06 | 10.04 | 1.06 | 128.67 | 856.57 | 33.84 | 418.56 |
1 Energy Industries | 12105.56 | 0.48 | 0.1 | 31.86 | 2.39 | 0.8 | 235.8 |
2 Manufacturing and Construction Industries | 9348.2 | 5.77 | 0.81 | 46.39 | 711.39 | 9.8 | 150.34 |
3 Other Sectors | 4067.77 | 1.33 | 0.044 | 5.75 | 19.96 | 1.28 | 10.8 |
a) Commercial Institutional | 322.39 | 0.14 | 0.004 | 0.45 | 2.36 | 0.14 | 2.5 |
b) Residential | 2235.93 | 0.50 | 0.02 | 3.2 | 6.87 | 0.27 | 1.6 |
c) Agriculture/Forestry/Fisheries | 1509.45 | 0.69 | 0.02 | 2.1 | 10.73 | 0.87 | 6.7 |
4 Other (including transportation) | 7633.54 | 2.46 | 0.11 | 44.67 | 122.83 | 21.96 | 21.62 |
B Fugitive Emissions | 0 | 0.54 | 0 | 0.39 | 0.59 | 36.15 | 6.09 |
1 Solid Fuels | NO | ||||||
2 Oil and Natural Gas | 0 | 0.54 | 0 | 0.39 | 0.59 | 36,15 | 6.09 |
INDUSTRIAL PROCESSES | 2268.5 | 0 | 3.32 | 8.02 | 1.57 | 65.67 | 8.19 |
A Mineral Products | 1605.91 | 0 | 0 | 0 | 0.0002 | 53.92 | 0.99 |
B Chemical Industry | 261.7 | 0 | 3.22 | 7.96 | 1.38 | 0.82 | 6.95 |
C Metal Production | 400.89 | 0 | 0 | 0.01 | 0.0003 | 0.01 | 0.01 |
D Other Productions | 0 | 0 | 0 | 0.05 | 0.19 | 10.92 | 0.24 |
1 Pulp and Paper | 0 | 0 | 0 | 0.05 | 0.19 | 0.12 | 0.24 |
2 Food and Beverage | 0 | 0 | 0 | 0 | 0 | 10.8 | 0 |
USE OF SOLVENTS | 7.3 | ||||||
A Application of Paints | 4.026 | ||||||
B Other | 3.312 | ||||||
1 Printing Industry | 0.185 | ||||||
2 Domestic Uses of Solvents | 2.53 | ||||||
3 Asphalt Polymerization | 0.537 | ||||||
AGRICULTURE | 0 | 374.51 | 51.91 | 4.27 | 75.09 | 0 | 0 |
A Enteric Fermentation | 346.44 | ||||||
B Manure Management | 17.85 | ||||||
C Rice Cultivation | 6.64 | ||||||
D Agricultural Soils | 51.78 | ||||||
E Prescribed Burning of Savannas | NO | NO | NO | NO | NO | 0 | 0 |
F Burning of Agricultural Wastes | 3.58 | 0.13 | 4.27 | 75.09 | 0 | 0 | |
LAND USE CHANGE AND FORESTRY | -23998 | 1.53 | 0.01 | 0.38 | 13.41 | 0 | 0 |
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-27282.5 | ||||||
B Forest Conversion | 3242.03 | 1.53 | 0.01 | 0.38 | 13.41 | 0 | 0 |
C Abandonment of Cultivated Lands | NO | NO | NO | NO | NO | NO | NO |
D Emissions and Removals from the Soil | 42.5 | ||||||
WASTES | 123.58 | ||||||
A Disposal of Solid Wastes | 71.09 | ||||||
B Waste Water Treatment | 52.49 | ||||||
1 Industrial Effluents | 45.95 | ||||||
2 Domestic and Commercial Waste Waters | 6.54 | ||||||
MEMO1 | |||||||
International Bunkers | 1143.99 | 0.05 | 0.023 | 15.61 | 15.46 | 2.15 | 11.075 |
Air Transport | 450.53 | 0.003 | 0.018 | 1.90 | 6.32 | 0.32 | 0.125 |
Maritime Transport | 693.46 | 0.046 | 0.005 | 13.71 | 9.14 | 1.83 | 10.95 |
CO2 Emissions from the Biomass | 21380.84 |
NO - It doesn’t happen. NE - Not Estimated.
1- Not included in the total of the Energy Module.
The negative values indicate net removals.
Table III. Total Net Emissions and Removals of GHG (Gg). Cuba, 1994.
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NATIONAL TOTAL | -4168 | 445.85 | 16.94 | 66.59 | 404.42 | 35.73 | 403.22 |
ENERGY | 21375.41 | 5.98 | 0.66 | 66.11 | 404.34 | 10.92 | 398.12 |
A Burning of Fuels (reference) | 21375.41 | ||||||
A Burning of Fuels (sectoral) | 22581.96 | 5.52 | 0.66 | 66.03 | 404.2 | 9.24 | 396.69 |
1 Energy Industries | 10774.61 | 0.74 | 0.18 | 31.33 | 26.73 | 1.95 | |
2 Manufacturing and Construction Industries | 6266.89 | 2.91 | 0.41 | 26.52 | 352.02 | 4.98 | |
3 Other Sectors | 2765.89 | 1.01 | 0.03 | 4.15 | 14.94 | 1.3 | |
a) Commercial Institutional | 318.86 | 0.09 | 0 | 0.46 | 0.84 | 0.11 | |
b) Residential | 1267.79 | 0.35 | 0.01 | 1.88 | 4.84 | 0.31 | |
c) Agriculture/Forestry/Fisheries | 1190.04 | 0.57 | 0.02 | 1.81 | 9.26 | 0.88 | |
4 Other (including transportation) | 2763.78 | 0.86 | 0.03 | 4.03 | 10.51 | 1.01 | |
B Fugitive Emissions | 0 | 0.46 | 0 | 0.09 | 0.14 | 1.69 | 1.43 |
1 Solid Fuels | NO | ||||||
2 Oil and Natural Gas | 0 | 0.46 | 0 | 0.09 | 0.14 | 1.69 | 1.43 |
INDUSTRIAL PROCESSES | 926.19 | 0 | 0.17 | 0.48 | 0.08 | 20.2 | 5.1 |
A Mineral Products | 690.19 | 0 | 0 | 0 | 0 | 11.65 | 0.33 |
B Chemical Industry | 0 | 0 | 0.17 | 0.45 | 0 | 0 | 4.65 |
C Metal Production | 236 | 0 | 0 | 0.01 | 0 | 0 | 0.01 |
D Other Productions | 0 | 0 | 0 | 0.02 | 0.08 | 8.55 | 0.11 |
1 Pulp and Paper | 0 | 0 | 0 | 0.02 | 0.08 | 0.06 | 0.11 |
2 Food and Beverage | 0 | 0 | 0 | 0 | 0 | 8.49 | 0 |
USE OF SOLVENTS | 4.61 | ||||||
A Application of Paints | 1.96 | ||||||
B Other | 2.65 | ||||||
1 Printing Industry | 0.06 | ||||||
2 Domestic Uses of Solvents | 2.59 | ||||||
3 Asphalt Polymerization | 0 | ||||||
AGRICULTURE | 0 | 352.44 | 16.11 | NE | NE | 0 | 0 |
A Enteric Fermentation | 333.01 | ||||||
B Manure Management | 15.55 | ||||||
C Rice Cultivation | 3.88 | ||||||
D Agricultural Soils | 16.11 | ||||||
E Prescribed Burning of Savannas | NO | NO | NO | NO | NO | NO | NO |
F Burning of Agricultural Wastes | NE | NE | NE | NE | 0 | 0 | |
LAND USE CHANGE AND FORESTRY | -26469.6 | NE | NE | NE | NE | 0 | 0 |
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-28546.2 | ||||||
B Forest Conversion | 2076.56 | NE | NE | NE | NE | 0 | 0 |
C Abandonment of Cultivated Lands | NO | NO | NO | NO | NO | NO | NO |
D Emissions and Removals from the Soil | NE | ||||||
WASTES | 87.43 | ||||||
A Disposal of Solid Wastes | 55.91 | ||||||
B Waste Water Treatment | 31.52 | ||||||
1 Industrial Effluents | 24.17 | ||||||
2 Domestic and Commercial Waste Waters | 7.35 | ||||||
MEMO1 | |||||||
International Bunkers | 249.71 | 0.07 | 0.01 | 1.04 | 3.29 | 0.17 | 0.13 |
Air Transport | 245.95 | 0.07 | 0.01 | 0.97 | 3.24 | 0.16 | 0.06 |
Maritime Transport | 3.76 | 0.00 | 0 | 0.07 | 0.05 | 0.01 | 0.07 |
CO2 Emissions from the Biomass | 11769.78 |
NO - It doesn’t happen. NE - Not Estimated.
1- Not included in the total of the Energy Module.
The negative values indicate net removals.
Fig. I. Contribution of each module (sector) to the total emissions
of GHG and other gases of radiative
importance (Gg). Cuba, 1990 and 1994. The CO2 emissions
coming from the burning of biomass for energy
that appear in the figure are presented only for information and are
not included in the total.
Module 1: Energy
In this module, the estimate of GHG and SO2 emissions coming from energy activities is approached. It is divided in two main categories:
Burning of Fuels
The CO2 emissions resulting from the burning of fuels were calculated using both the reference or "top-down" approach (Fig. II), and the sectoral approach – or method by categories of sources of the IPCC (Fig. III). The sectoral approach refers to the calculation of the emissions starting from the carbon content of the fuels supplied to the main combustion activities – categories of sources.
Fig. II. Emissions of CO2 resulting from the burning of fossil
fuels. Reference approach.
Cuba, 1990 (33 279.2 Gg) and 1994 (21 375.41 Gg)
Fig. III. Emissions of CO2 by categories of sources – sectoral
approach (Gg).
Cuba, 1990 and 1994.
As observed in the Fig. II, the CO2 emissions calculated using the reference approach verified a remarkable reduction between 1990 and 1994 – from 33 279,26 Gg to 21 375,41 Gg. For both years it can be appreciated the fundamental importance of the burning of liquid fossil fuels in these emissions. In the sectoral approach (Fig. III), it was obtained a reduction in the CO2 emissions from 33 155,1 Gg in 1990 to 22 581,96 Gg in 1994. Likewise, the emissions of gases other than CO2 were also calculated in this section, about which a summary is presented in Fig. IV. For all these gases reductions in the emissions were also appreciated, although in the case of SO2 this decrease was attenuated by the increment in the use of the Cuban raw oil with a high sulfur content.
Fig. IV. Emissions of GHG other than CO2 resulting from the
burning of fuels (Gg).
Cuba, 1990 and 1994.
Electricity Generation and Mobile Sources
For their importance for the emissions in this module, the emissions coming from electricity generation and mobile sources were calculated in detail in the inventory. In the case of electricity generation, the calculation was carried out through the DECADES software of the IAEA (IAEA, 1999). Between 1990 and 1994, a reduction of 41,87% in the emissions of GHG took place in that sector (of 15 899,29 Gg to 9 241,89 Gg (Fig. V).
Regarding the terrestrial mobile sources, it was used the methodology developed for its application in the European Economic Community (EEC), but using emission factors of that methodology modified starting from studies developed in Cuba –by the Center of Studies and Development of Transport (CETRA). For the calculation it was taken into account the type of vehicles, the type of fuel consumed, the exploitation characteristics of the pool of vehicles, technologies for emission control and other factors (Table IV). In the analysis of highway automotive vehicles, it was included the analysis of the emissions of light, medium and heavy vehicles, all subdivided according to the type of fuel used – diesel or gasoline. In the other mobile sources the calculation was approached separately for railroads, agricultural and construction equipment, as well as maritime vessels.
Fig. V. Emissions of GHG resulting from electricity generation (Gg).
Cuba, 1990 and 1994.
Table IV. Emissions of GHG resulting from the mobile sources (Gg). Cuba, 1990 and 1994.
Year | CO2 | CH4 | N2O | NMVOC | CO | NOx | |
Automotive
Vehicles |
1990 | 5649.8 | 1.19 | 0.14 | 67.3 | 500.2 | 67.1 |
1994 | 1444.9 | 0.42 | 0.04 | 33.88 | 137.13 | 19.95 | |
Other mobile sources (1) | 1990 | 2467.4 | 0.8 | 0.92 | 25.0 | 197.5 | 35.5 |
1994 | 1602.98 | 0.19 | 0.64 | 4.49 | 8.38 | 24.61 | |
Maritime Vessels | 1990 | 858.2 | 0 | 0.02 | 0 | 0.51 | 23.25 |
1994 | 369.06 | 0 | 0.009 | 0.004 | 0.23 | 9.99 |
1) It includes railroad, agricultural and construction equipment.
In this module, the calculation of the emissions coming from air transport in civil aviation was also undertaken. This analysis was done separately for domestic and international flights – the emissions of the latter are not included in the national total – as well as according to the operations of the aircraft– the landing and take-off cycles or the cruise operations. In Table V, a summary of these emissions is presented for domestic flights, where it can be appreciated the slight increment observed between 1990 and 1994.
Table V. Emissions of GHG coming from air transport in
civil aviation for
domestic flights (Gg). Cuba, 1990 and 1994.
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Fugitive emissions
All the methane (CH4) emissions coming from production, processing, transport and uses of oil and natural gas, as well as of the non-productive combustion, are included in this category. It is excluded the use of the oil and gas, or of the fuel byproducts, to provide energy for internal use in the processing and transport of the energy production –they are considered as burning of fuels and were already included in a previous epigraph. The emissions of carbon monoxide (CO), nitrogen oxides (NOx), non-methane volatile organic compounds (NMVOC) and sulfur dioxide (SO2) coming from the oil refining activities are also estimated. A summary of these emissions is presented in Fig. VI.
Fig. VI. Fugitive emissions from oil and natural gas operations (Gg).
Module 2: Industrial Processes
This module includes the greenhouse gas emissions that take place in industrial activities and that are not related with energy. Here, the main sources are those processes of industrial production that transform materials physically or chemically. The calculations of emissions were done for the following four main categories of sources of emissions that occur in the country –for each of these main categories, the calculations of emissions for the types of sources indicated between parenthesis were also done.
Table VI. Emissions of GHG resulting from industrial processes (Gg). Cuba, 1990 and 1994.
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Module 3: Use of Solvents and Other Products
The emissions of Non-Methane Volatile Organic Compound (NMVOC) coming from a great variety of anthropic production processes and consumption that involve the application of organic solvents are calculated in this module.
In the inventory the calculation of emissions is approached from some fundamental sectors such as the application of paintings by types – enamels, lacquers, varnishes, oil paintings, emulsified paintings–, the degrease of metals and other materials, the industry of graphic arts – due to the printing techniques and according to the content of solvents in the inks used–, asphalt polymerization, as well as the domestic uses of solvents.
The emissions due to the dry laundry of textiles and clothing using organic non-aqueous solvents were not included, because the necessary activity data to undertake the calculations are not available. Nevertheless, it is considered that the emissions coming from that activity, in the country, are very low. A summary of the total emissions of NMOC coming from the use of solvents is shown in Fig. VII, by categories of sources for 1990 and 1994.
Fig. VII. Emissions of GHG resulting from the use of solvents and other
products (Gg).
Cuba, 1990 and 1994.
Module 4: Agriculture
The Agriculture module comprises the emissions of greenhouse gases coming from five sources:
Methane emissions can take place starting from the excreta of domestic animals, being the most important potential emissions those that come from the beef cattle and porcine livestock. This methane is produced fundamentally by the decomposition of the manure under anaerobic conditions, and the quantity that is released to the atmosphere depends on several factors such as animal population, daily average of volatile solids excreted, potential production of methane from the manure and from the manure management system, among other.
During the cultivation of rice, gas methane is produced as a consequence of the anaerobic decomposition, by microorganisms in the soil, of the organic matter under the flood waters. The CH4, is produced by the reduction of CO2 with hydrogen, reaction that depends on the quantity of agents that donate hydrogen and on the soil type.
In Cuba, the prescribed burning of savannas and grassland is not carried out since it is institutionally forbidden, in this sense it is possible only to calculate such emissions when accidental fires take place, which are analyzed in another module of the Inventory. Something similar happens with the burning of agricultural wastes in the field that is admitted in exceptional cases, like for example the burning of sugarcane fields for different purposes –the burning of sugarcane fields was included in the inventory corresponding to 1990, but they could not be approached in that of 1994 due to the lack of the necessary information for the calculations.
It is accepted that agricultural soils constitute an important source from where nitrogen gases are emitted, the GHG N2O among them. The direct emissions of N2O coming from agricultural soils, the direct emissions of N2O from the soils devoted to animal production, and the indirect emissions of N2O coming from the nitrogen used in agriculture were calculated in the inventories. Fig. VIII offers a summary of the emissions for the common categories in 1990 and 1994. Moreover, 3,58 Gg of CH4; 0,13 Gg of N2O; 75,09 Gg of CO, and 4,27 Gg of NOx were emitted in 1990, resulting from the burning of sugarcane fields.
The causes of the differences obtained among the emissions for those two years were:
Fig. VIII. Emissions of GHG coming from the agricultural activities. Cuba, 1990 and 1994.
Module 5: Land Use Change and Forestry
In this module, the calculations of the emissions and removals resulting from the land use change and forestry are prioritized for four activities that are sources or sinks of carbon dioxide:
The estimate of the quantity of harvested biomass starts from the data of wood commercial harvest, the total consumption of firewood –including the wood used in the production of charcoal–, as well as other wood consumption. To the data of commercial crop it was applied an expansion rate to count the non-commercial biomass –branches, small trees, etc.– harvested together with the commercial logs and abandoned for their decomposition. All the data were also converted from cubic meters to tons of dry matter (t ms).
Starting from the data of deforested surfaces, the estimates of the
pruning were made according to the political–administrative division. The
estimate for the year 1994 was much lower than that of other previous years.
To obtain the estimates of the CO2 emissions resulting from
the conversion of forests and grasslands, calculations were done for the
following processes:
In relation to the net removals of CO2 due to the accumulation of biomass coming from the abandonment of cultivated lands, they are assumed as zero in the inventory because in Cuba the abandonment of lands does not take place. Due to the economic crisis experienced by the country since 1989, there was a great growth of plant species like Dichrostachys cinerea (marabú) and Acacia farnesiana (aroma) in large extensions of land devoted to cattle raising. For 1994, there was no information of good quality available on this topic that facilitated the estimate of removals due to the re-growth –or emissions caused by the burning–of this type of vegetation.
Estimates relating to carbon changes in the mineral soils could not be approached in the inventory for not having the adequate maps of land use, in the appropriate scales, corresponding to the years requested in the inventory to make the calculation. The execution of this topic required of funds that were not available to undertake the task, a part of which was necessary for the obtaining or use of cosmic and air images. In relation to the emissions coming from organic soils converted to agriculture or plantations, it is not considered of relevance for the country and thus it was not included in the calculations.
By way of summary of this module (Fig. IX), it can be stated that in
1990 it took place a net removal of 23 998 Gg of CO2 due to
3 660,88 Gg of emissions and
27 658,88 Gg of removals. In 1994, the emissions of CO2
in this sector were 2 375,04 Gg, with removals of 28 841,01 Gg of this
gas, to generate a net removal of 26 469,6 Gg of CO2. Besides,
1,53 Gg of CH4; 0,01 Gg of N2O; 13,41 Gg of CO, and
0,38 Gg of NOx were emitted in 1990 from forest fires of anthropic origin.
Fig. IX. Emissions and Removals of CO2 resulting from land
use change and forestry (Gg).
Cuba, 1990 and 1994.
Module 6: Waste
This module presents the estimate of methane emissions (CH4) from the managed solid waste disposal sites (MSWDS), and the treatment of waste waters –divided in domestic/commercial waste waters and industrial efluents.
Methane is the most important GHG generated by waste disposal and treatment, especially from the anaerobic systems used for the management of biodegradable wastes resulting from human activities: sanitary fillings and waste water treatment.
The emissions of CH4 from wastes were estimated in 123,58
Gg in 1990 and 87,43 Gg in 1994. This reduction was motivated not only
by the decrease in the solid waste generation per capita by the population
–from 0,686 kg/inhab/day in 1990 to 0,577 kg/inhab/day in 1994-, but also
by the reductions observed in the productions of an important group of
the country’s industrial processes and the consequent decrease in their
effluents. The summary of the CH4 emissions resulting from wastes
in 1990 and 1994 is exposed in Fig. X.
Fig. X. Emissions of CH4 resulting from wastes (Gg). Cuba, 1990 and 1994.
IV. Quality Assessment and Management of Uncertainties
Uncertainties are unavoidable in any national estimate of the emissions and removals. Some of their more common causes are the difference in the interpretation of the categories of sources and sinks, or other suppositions; the use of representations simplified with "mean" values, especially the emission factors; the uncertainty of the basic data and the uncertainty inherent to the scientific understanding of the basic processes that lead to the emissions and removals.
A valuation of the quality and uncertainty of the estimates of emission obtained in the inventory is approached in this module. For that purpose, the recommendations established in the Guides of the IPCC (IPCC-OECD- IEA, 1997) are applied, as well as other complementary procedures, especially those that appear in the methodologies CORINAIR, 1996 and U.S, EPA, 1995. The methods used are considered provisional, until the Guides of the IPCC for Good Practice and Management of Uncertainties in the Inventories of Greenhouse Gas Emissions, which are being elaborated when the compilation of these inventories was done, are put into practice.
The quality control activities in the inventories were directed toward the assessment of the procedures used in the processing, management, documentation, filing and report. The verification of the calculation procedures and of the applicability of the emission factors by default of the IPCC were included here, as well as the comparison of the emissions calculated with those estimated for Cuba in international reports; the verification of the procedures for documentation, filing and report; and of the common framework for the realization of the report.
Among the quality insurance activities undertaken, it was developed a process of review of the inventory by third parties –experts directly linked to the elaboration of the inventory. The activities developed as part of this review process provided useful approaches and recommendations that were incorporated to the inventory, or they detected potential problems, allowing for their correction before the publication and transmission of the inventory
In order to evaluate the quality of the emission estimates, it was applied a qualitative method based on the approaches of experts for each source category and GHG emitted. In this method a letter is assigned to each emission factor and activity data used, according to a quality scale that, by combination, allow to obtain a final assessment factor. After the uncertainties were determined in the categories of sources, they were combined to obtain estimates of uncertainties for each module of the inventory and for the complete inventory. The procedures exposed in Volume I of IPCC Guides and in EMEP-CORINAIR, 1996, have been applied in a combined way for this assessment. In this scheme, as it was used for the assessment of uncertainties in the inventory of Cuba, the final quality assessment factor (from A to E) has an inverse order in relation to the uncertainty (Table VII).
Table VII. Scheme for the classification of quality and uncertainty.
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A summary of the results obtained in this evaluation for the years 1990
and 1994 is shown in Fig. XI and Table VIII. In general, an improvement
is appreciated for 1994 in the quality of the emission estimates (92,4%
of the estimates qualified as A, B or C in 1994 and 87.2% in 1990. This
improvement is appreciated in industrial processes and agriculture, while
in energy, land use change/forestry, and wastes, a slight decrease in the
quality of the estimates occurred in 1994.
Fig. XI. Percent distribution of the occurrence of quality categories
of the emissions
obtained in the inventory. Cuba, 1990 and 1994.
Table VIII. Percent distribution of the occurrence of
quality categories in the emissions for
each module of the inventory. Cuba, 1990 and 1994.
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V. Relative contribution to Global Warming. Aggregated emissions in CO2 Equivalents (CO2-e)
The different gases do not contribute in the same degree to the increment of the greenhouse effect. To express the emissions of GHG on an equivalent baseline that reflects their contribution to the possible future warming, the Atmospheric Global Warming Potentials (GWP) are used.
The GWP of a GHG is defined as the cumulative radioactive forcing between the present and some selected temporary horizon that is caused by an unit of gas mass emitted now and expressed as related to CO2. Its value depends not only on the persistence of the gas in the atmosphere but also on its radiative forcing. It includes the direct effects of the substances on the radiation –fundamentally the removal of infrared radiation-, as well as the indirect chemical effects on the radiation balance. The expressions of the emissions in "CO2 equivalent" (CO2-e) indicate the level of CO2 that would cause the same level of radiative forcing as the given mixture of this gas, other greenhouse gases and the aerosols. Table IX exposes the relative contribution to the radiative forcing of the emissions estimated in the inventory for the main gases of direct greenhouse effect. The values of PCG for a 100-year temporary horizon reported in the Second Assessment Report of the IPCC (IPCC, 1995) are used in the calculation.
As it can be appreciated from the table, if absolute or gross emissions are considered, in 1990 the main radioactive forcing comes from the emissions of CO2 with a relative contribution of 55,71%, followed by CH4 with 16,85%, and N2O with 27,44%. If the analysis is carried out starting from the net emissions, N2O provides the main forcing with 44,08%, followed by CO2 with 28,85%, and very close to this, CH4 with 27,06%. In 1994, starting from the absoluteor gross emissions, the main radiative forcing was produced by CO2 with a relative contribution of 60,41%, then CH4 with 25,36% and N2O with 14,23%. Starting from the net emissions, the contribution of the CO2 is null. Between 1990 and 1994 a remarkable reduction of the added emissions of the GHG of direct effect took place in the country, expressed in CO2-e.
Table IX. Relative contribution of the main gases of direct
greenhouse effect to the radiative forcing.
Cuba, 1990 and 1994.
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100 years |
Total 1990 |
Total 1994 |
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1) The emissions and removals resulting from land use
change and forestry are not considered.
2) The emissions and removals resulting from land use
change and forestry are considered.
3) That relative contribution was estimated starting
from the sum of the emissions of CH4 and N2O.
4) It only includes CH4 and N2O.
AE = Aggregated Emission.
7. Emissions of CO2 and Carbon Per Capita
Special care should be taken when using or comparing data of emissions per capita among the different countries, because it must be ensured that they have been obtained using the same calculation estimates. There exist marked differences in many published reports, because some of the estimates come from considering net emissions taking into account the emissions and removals of the "Land Use Change and Forestry" module, while in other reports this module is not taken into consideration or the removals that occur in it are not considered. Other estimates only take into account the emissions coming from the burning of fuels and some industrial processes of great significance for the emissions, like that of cement production.
The results obtained starting from net emissions (considering the emissions
and removals of the Land Use Change and Forestry module), as well as those
starting from absolute emissions –without considering the above-mentioned
module– are exposed in Fig. XII. As it is appreciated, the results of the
emissions per capita differ notably according to the form of calculation
applied.
Fig. XII. Emissions of CO2 and Carbon per capita in Cuba,
for 1990 and 1994.