SUMMARY: Mexico's Country Study comprises analyses in three major areas: Inventory of Emissions of Greenhouse Gases; Scenarios, both physical and of emissions of GHG; and a Study of Vulnerability of the Country to Global Climate Change.
The project intends to provide support and information to policymakers so that strategies can be redirected to face the effects of Climate Change. These analyses are intended to show the possible impacts on different productive activities and resources, and the new alternatives and challenges that Mexico's development will confront with respect to their corresponding emissions of GHG.
In the area of inventories, it was found that Mexico emits about 85.4 x 106MTC (metric tons) of carbon due to burning of fossil fuels. The methane emissions coming from urban waste disposal sites amount to 385.9 x 103 MT per year. Methane from agriculture and livestock amounts to 35,000 MT and 1.804 x 106 MT respectively, showing a very small contribution due to rice cultivation. The contribution to the emissions due to land use change varies from 49 to 129.3 million tones of CO2 depending on the use of a low or high rate of deforestation. The estimations for fugitive emissions of methane from the oil industry vary from 435 x 105 MT to 1.07 x 106 MT, depending again in the use of low and high emissions factors, respectively.
In the area of physical scenarios, different GCMs have been used to produce maps of temperature and precipitation under the assumption of CO2 doubling. An effort is being made to obtain results for regional scenarios using GCMs.
In the area of emission scenarios, several numerical experiments
been carried out using "bottom up" and "top down" models and
projections of land use change. Even when structural changes are
introduced in the energy sector, all the possible and probable
lead to an increase in the consumption of energy and an increase in
emissions of GHG. This result is mainly due to a certain inertia in the
economic structure. The increase in emissions of GHG is due to the
assumption of continuous growth of the industrial, agricultural, and
economic activity of the country.
These organizational efforts have contributed to increase Mexico's participation in international symposiums. However, we have had difficulties, especially related to financial support. Because of these financial constraints, the U.S. Country Studies Program was welcomed with enthusiasm, and Mexico presented the project titled "Country Study: Mexico," which was later approved.
This project represents an ambitious plan whose objective is to understand what impact climate changes may have on human activities and to provide the basis for the delineation of national strategies, which must integrate economic issues with climate- environmental policies.
The project's main objectives are:
In order to estimate CO2 emissions, we used national emission factors along with the OECD/IPCC methodology, and production and consumption data from the National Energy Balance for 1990. The estimate of carbon emission comes from a mass evaluation where: According to the OECD/IPCC methodology (IPVV, 1995), energy produced by the combustion of firewood and bagasse must not be included in these estimates. Because of this, the values for CO2 emissions will have to be subtracted from the final figures.
Based on the National Energy Balances, the energy sector in
93,251,375.4 Metric Tons of Carbon, equivalent to: 341,921,658.7
Metric Tons of
Carbon Dioxide. The cement industry accounts for 13,420,290 Metric
Tons of Carbon
Dioxide. Total emissions are 96,911,079.4 Metric Tons of Carbon,
355,341,448.7 Metric Tons of Carbon Dioxide. Subtracting
originating from the combustion of firewood and bagasse, we are left
with a total of
85,368,695.2 Metric Tons of Carbon and 313,018,540 Metric Tons of
The figures for the methane emissions by ton of waste are computed for the Federal District and for the rest of the country as an average of the four remaining regions. With these values in hand, we were able to estimate total methane emissions at 385,900 tons per year.
The forested surface areas in Mexico were categorized by State, ecosystem, and type of vegetation, based on data from the National Forest Inventory of Great Vision of 1992, published by the Department of Agriculture and Hydraulic Resources.
The real forested area for 1990 was equivalent to 133,740 Kha. On the basis of this fact, the surface area was delineated by type and subtype of vegetation according to its management. It should be noted that the forested area that is in very damaged condition totals 3,548 Kha. These areas are not taken into account since they cannot be recovered.
In order to estimate emissions from the submodule "felling of forests CO2 release originating from biomass burning, in situ and outside," we took into account high and low deforestation rates. In 1990 a total of 370,000 ha. were deforested, observing a greater cutting for tropical forests than for forests and arid zones. The present study works with a high rate of deforestation, and arrives to a total estimate of 767,186 ha. It should also be noted that there are other reports in which higher deforestation rates are mentioned. Toledo (1989) estimates an annual deforestation rate of 1,500,000 ha.
Mexico, however, lacks detailed information on the total biomass area for the different types of vegetation. Estimates are computed based on commercial biomass inventories, using expansion factors. If we estimate the biomass area by type of forest prior to deforestation, the biomass values after deforestation would be the ones put forth by IPCC. After deforestation, the biomass depends critically on the type of use given to the deforested area. For example, tropical forests are more affected because of extensive cattle rearing, whereas fires are the most important cause of deforestation in temperate forests.
If we use a low deforestation rate, our estimate for carbon release equals 13,365 Gg and 49,005 Gg of CO2. If we use a high rate, our estimate would equal 35,260 Gg of Carbon and 129,290 Gg of CO2. The aforementioned results are preliminary since we are currently working on generating our own data for the portion of burned biomass, for combustion efficiency, and for carbon content in the burned biomass.
In the case of Mexico, the greatest uncertainty in terms of methodology is its regional definition. Mexico is classified as an "Other Petroleum Exporting Country," since it consumes approximately 94 percent of the natural gas produced globally. After consulting with the technical advisors from the firm ICF, it was decided to classify Mexico as member of "Rest of the World Region." The emission factors can be found under this category on Table 1 47 of the Reference Manual. The methane emission estimates, for high and low emission coefficients, are 435 and 1069Gg, respectively.
The National Energy Balance reports a total gas production of 1640PJ and a total consumption of 1555PJ, including internal consumption within the petroleum industry. The difference of 85PJ is equivalent to 1703Gg of natural gas. Considering that methane represents 50 percent of the weight of the Mexican natural gas, the aforementioned 85PJ would be equivalent to 851Gg of methane. This quantity is energy not used and lost in transformations and ventings, and represents by itself a very small quantity of methane emissions from the petroleum industry. The high emission estimates are considered as the most representative of the "Tier 1" of the methodology. According to "Tier 1," the main sources of fugitive emissions are venting and flaring, originating from petroleum and natural gas production, from emissions in the processing, transportation and distribution of natural gas, and from leakages in industrial and powerplants. On the other hand, emissions which resulting from the transportation, storage, and refining of crude petroleum, from maintenance of production facilities for oil and gas, and from leakages in the commercial and industrial sectors, are considered marginal.
In order to create future scenarios, we used the methodology put forward by the IPCC and discussed in "U.S. Country Studies Program's Training Workshop on Vulnerability and Adaptation Assessments" in Washington D.C., in February of 1994.
This process consists of adding the temperature increments given by the models, to the climate conditions of the places or regions to be studied. For the central region of Mexico, we used the predictions of GFDLR30 and of the Canadian Climate Model. And, by way of comparison, we have also used the thermodynamic climate model developed by the Center for Atmospheric Sciences of the University of Mexico.
For future scenarios, we operated with the GRIDS package (Kentery Dotty, 1994) and, by either interpolation or use of the nearest data point provided by the GCM, we arrived at estimates of temperature and precipitation increments for the 23 locations. This material was presented in a technical report No. 1 in the form of tables, maps, and diskettes.
With the intention of validating the models, we proceeded to compare its simulations for 1 x CO2 with the climate values obtained and, in so doing, we observed important differences when the comparisons were conducted site by site. The comparisons were also conducted by taking averages of points contained in latitude bands. This comparison was more favorable and enabled us to affirm that for the northern region the results were similar for the three models employed. Although the magnitudes are different for the central and southern regions, the GFDL model reproduces better the seasonal changes. It should be noted that temperature compared to precipitation exhibits greater cohesion the GFDL model predicts greater precipitation for an extensive region centered in the middle portion of Mexico, while CCCM forecasts exactly the opposite.
Due to the fact that the distance between the grid points of the models is several hundreds of kilometers (approximately 400 kms), the regional characteristics are not reproduced. In order to solve this problem, we are in the process of studying the adjustments needed to obtain simulations at a regional and even local level, either by nesting regional climate models into GCMs or by regionalizing GCM simulations with empirical formulations.
The methodology for "bottom up" or end-use analysis focuses on energy conservation. This analysis is put forward as an alternative to the traditional approach which employs Gross Domestic Product, income, and price as economic variables which explain the demand for energy.
This approach steers the analysis toward the demand for energy and not toward its aggregate supply. Energy consumption is disaggregated for the different sectors, and sums different end-uses from each sector. This procedure incorporates structural demands as explicit elements and allows for the accounting of energy needs in relation to physical and economic activities.
For the elaboration of future energy consumption scenarios and for the quantitative analysis of atmospheric emissions, different models have been developed most notably, the STAIR model. This model, the name of which is formed by the five sectors which consume energy: services, transportation, agricultural, industrial, and residential, is basically an accounting framework based on the methodology by end uses. It makes possible the study of impacts of different energy policies on the use of energy as well as in the emissions of greenhouse gases (Ketoff, Sathaye, 1991).
Emission factors represent the average behavior of a similar set of technologies and may fluctuate according to: type of fuel, technology, how old the technology in question is, and the conditions under which it is operated and maintained.
Scenarios of Social and Economic
Three different scenarios were elaborated for the period from 1990 to 2025. Gross Domestic Product was assumed to grow at an average annual rate of 4 percent, population at 1.8 percent. The energy consumption structures remaining stable for each sector, as well as the emission factors.
In scenario A, a society that wastes its natural resources is portrayed, corresponding with the current national trend. By the year 2025, a per capita annual consumption of 350GJ would have been reached, equivalent to the consumption of the United States in 1982.
In scenario B, a society that aims at conserving its resources is depicted, in correspondence with the intentions of the current energy policy. By the year 2025, a per capita annual consumption of 200GJ would have been reached, equal to the consumption exhibited by Germany in 1982.
In scenario C, a society which has sustainable growth is reached, requiring changes in the social and industrial structure, as well as giving special attention to the environment. By the year 2025 a per capita annual consumption of 100GJ would have been reached, slightly lower than that of Japan in 1982.
The main environmental problems (local and global) originating from the energy system come from the great dependence on hydrocarbons, carbon, and wood burning; from the characteristics of refined crude oil, 31 percent of which is heavy crude, with an average of 3.3 percent sulphur content; from the great urban agglomerations which are still growing, headed by the metropolitan area of Mexico City (and whose transportation system is insufficient); from the absence of norms for the control of emissions from the energy sector, transportation, and the industry in general; and from the insufficient use of energy.
However, there are substantial changes within subsectors of a particular sector. In the industrial sector, the participation of basic petrochemicals will increase by 50 percent by the year 2000 and will triple by the year 2010. The chemical industry will also grow, doubling its participation by the year 2010, just like that of fertilizers, which, in addition, will quadruple by the year 2020.
The total energy consumption increases by 38 percent over the current level by the year 2000, by 100 percent by the year 2010, and by 500 percent by the year 2024. This implies an annual growth of 3.8 percent for the whole period: in the short term until year 2000 the growth would equal 4.4 percent, decreasing thereafter. The corresponding quantities for GNP are 31, 85, and 421 percent, respectively. The tendencies shown are on the increase for energy intensity.
The scenario without changes (business-as-usual) works with a GDP growth rate of 3.5 percent and with constant energy intensity. The results show that total energy demand will increase from 1,499 x 1012 Kcal in 1992 to 3,124 x1012 in 2010, which would imply an annual growth rate of 4.1 percent. The generation of nuclear electricity (CFE) geothermic and hydro will not increase as projected (66 percent by the year 2000). So part of the electricity assigned to this area, will in due course be generated by fossil fuels; environmental problems will favor the use of natural gas. Nuclear installed capacity will grow to 1,300MW by next year. CFE plans contemplates an increase in generating capacity of 25 percent in geo and thermal power and 38 percent in hydro power by the year 2000.
In low-growth-rate scenarios, with a GDP growth rate of 2.0 percent and with constant energy intensity, we find the following: total energy demand goes from 1,461 x 1012 Kcal in 1992 to 2,385 x 1012 Kcal in 2010, a fact that implies an annual growth rate of 2.8 percent.
To the date, we obtained the following results: a bibliographic base with more than 80 files, sorted alphabetically and by topic (the same which is available at the Ecological Center of the UNAM); the publication of an article in the foremost Country Study Workshop; and the improvement of a data base with basic biophysical parameters for carbon emission and sequestration due to deforestation, using the model CO-PATH. This data base, includes estimation of gross, net, immediate, and long-term carbon emissions for the four types of closed forests in the country: temperate coniferous forests, oak forests, humid, and dry tropical forests. We also include biophysical and economic parameters for the options of carbon absorption for the conservation options for protected natural areas, forests, and native tropical forests management.
The analysis also addresses efficient use of firewood, agroforestry, and commercial and noncommercial reforestation plantations (including bioenergy projects). We initiated the elaboration of a data base, for the calculation of future scenarios for carbon emissions and absorption. The data base includes basic parameters on forest management and emissions by type of forest (taken from the previous data bases) and combines them with estimates for the evolution of the population, of the GDP, forest products demand and other estimate factors.
In order to design basic parameters for the reference alternative scenarios, we consulted with experts responsible for the areas of inventories and vulnerability. In the specific case of the forested sector, we put forth a reference scenario or a scenario of tendencies which would incorporate long-term emissions resulting from a continuation of historical deforestation rates (1980 1990).
Two policy scenarios moderate and accelerated will also be developed. Using 1990 as the base year, the projections will be provided for years 2025 and 2100.
Estimation of Greenhouse Emissions and Sinks. Final Report from
Experts Meeting, 18 21 February, 1991.
National Energy Balance, 1990 1991, SEMIP.
Preliminary Inventory of Greenhouse Effect Gases for Mexico,
INE/SEDESOL. Note: includes software developed in FORTRAN for the
elaboration of the inventory.
"XI GENERAL POPULATION AND HOUSING CENSUS, 1990"; National
Institute of Statistics, Geography and Data Processing; INEGI, July of
"Percentage Composition of Municipal Solid Residues by Zones";
Directorship for the Control and Prevention of Environmental
Operation directorship, SEDUE, 1988.
"Generation of Solid Residues by Zone", General Directorship for
the Control and
Prevention of Environmental Contamination, Operation directorship,
"Executive Summary on Technical Viability for Usage of Biogas
Generated in the
Final Disposal Sites for Municipal Solid Residues in the Federal
Secretary for Public Works; General Directorship of Urban Services,
Directorship of Solid Waste; DDF, October 1990, Mexico, Fed.
IEE/10/14/3128/i/03/P. " Laboratory Tests of the Samples
Obtained in the Probing
of the Santa Cruz Meyehualco and Santa Fe sites", "Evaluation of the
Generation of Electricity with Biogas from the Landfills of Urban Solid
IIE, A.P. 475, Cuernava, Mor. Mexico, October 1991.
"Methane Emissions Inventory by Agricultural Activities in
Mexico"; Gonzá lez
Avalos, E., Ruiz, L.G., Gay, C.: in Memoirs of Annual Meeting of
Program for the Environment (PUMA,1992).
"Agricultural, Livestock and Common Grazing Land Census, 1981.
Summary", Mexico, INEGI, 1981.
"Workbook for Inventories of Greenhouse Effect Gases", Vol. 2,
"First National Forestal Inventory", Subsecretaryship for Forestry,
SEMIP (1991) National Energy Balance 1990.
Garcia E. 1988. Modifications to Koppen's Climatic Classification
Edition. 217 p.
Rzedowski, J. 1992. Potential Vegetation Chart. National Atlas of
Biogeography Section IV.8.2 Scale 1:4,000,000. Institute of
National Commission for Energy Saving, 1992. Report. CONAE-
Fed. District. Mexico. Environmental Protection Agency, 1990.
"Sustainable use of fuelwood in Rural Mexico", Masera O.; CONAE-
Mexico, Federal District, 1993.
"National Energy Balance". Secretaryship of Energy, Mines and
industries. SEMIP, 1991.
Figure 1 Cumulative Area and Carbon
Table 1. Data From the Energy Balance of 1990 x 1,012 kilocalories Apparent Type of Fuel Produc. Import. Export. Stocks Consumption
Liquid Fuels Crude Oil 1401.26 0.00 708.86 -8.09 700.49 Condensed 57.27 0.00 0.00 -21.66 78.93 Gasoline NA 17.27 4.02 -0.73 13.98 Kerosene NA 0.00 7.51 -0.59 -6.92 Diesel NA 0.00 16.66 1.27 -17.93 Fuel Oil NA 30.16 4.45 -0.29 26.00 Solid Fuels Carbon 35.54 1.38 0.04 -1.46 38.34 Coke NA 0.83 0.03 0.16 0.64 Bagasse 20.70 0.00 0.00 -0.79 21.49 Firewood 70.73 0.00 0.00 0.00 70.73 Gas Fuels Liquefied Gas NA 3.11 18.12 0.04 -10.05 Associated Gas NA 0.00 0.00 12.27 -12.27 Gas Not Associated NA 0.00 0.00 -0.43 0.43 Gas 216.79 4.02 0.00 0.15 220.66
Table 2 Emission Factor Carbon Content CO2 Content Type of Fuel KgC/Gigajoules (103KgC) (103Kg)
Liquid Fuels Crude Oil 20.00 58,645,022.0 215,031,700.0 Condensed 20.00 6,608,020.0 24,229,404.0 Gasoline 18.90 1,106,033.2 4,055,454.3 Kerosene 19.60 -567,755.6 -2,081,770.3 Diesel 20.20 -1,516,110.5 -5,559,071.7 Fuel Oil 21.10 2,296,439.6 8,420,278.3 Solid Fuels Carbon 25.80 4,140,673.9 15,182,470.0 Coke 29.50 79,031.7 209,782.8 Bagasse 29.90 2,689,718.4 9,862,300.6 Firewood 29.90 8,852,665.8 32,459,774.0 Gas Fuels Liquefied Gas 15.30 -643,660.3 -2,360,087.6 Associated Gas 20.00 1,027,244.4 3,766,562.7 Gas Not Associated 20.00 35,999.6 131,998.5 Gas 20.00 18,473,655.0 67,736,773.0 TOTAL 101,226,976.8 371,1655,528.6
Table 3. Urban Solid Waste (USW) Deposited in Sanitary Landfills Millions of Tons Percentage of USW of USW Millions of Tons Disposed of in Disposed of of USW Generated Sanitary in Sanitary Country Zone by Year Landfills Landfills
Fed. District 4.197 65.50 2.749 Rest of Country 17.446 22.25 3.968
Table 4. Preliminary Estimate of Methane Emissions at a Nationwide Level for 1990 Annual Annual USW Disposed Methane Methane Methane of in Sanitary Output Emission Emission Landfills (millions From USW millions of m3 (millions of tons Country Zone tons/year) (m3 N/Ton USW) of methane/year) of methane/year)
Fed. District 2.749 88.9 244.38 174.5 Rest of Country 3.968 747.75 296.60 211.4 Total 6.717 540.98 385.9
Table 5. Preliminary Estimate of Emissions From Land Use Change
Low Rate (MT) High Rate (MT)
C 13,365,000 35,260,000 CO2 49,005,000 129,290,000
Table 6. Scenarios of Energy Consumption
Scenario A B C Year 1990 2025 2025 2025
GDP 1012 pesos of 1980 24 20.66 20.66 20.66 Annual average growth rate 4.00% 4.00% 4.00%
Population (millions of inhabitants) 81.14 160 160 160 Annual average growth rate 1.96% 1.96% 1.96%
Energy Intensity (Megajoules/pesos of 1980) 1.06 2.71 1.55 0.77
Per Capita Consumption (Gigajoules/inhabitant) 68.50 350 200 100
National Energy Consumption (exajoules) 5.56 56 32 16 Annual growth rate 6.82% 5.13% 3.07%
Table 7. 1990-91 Internal Energy Balances
1990 1991 Energy Supply 106 GJ % 106 GJ %
Domestic Production Hydrocarbons 7747.74 87.37 8007.48 86.8 Biomass(bagasse and fuelwood) 383.46 4.32 385.69 4.18 Hydraulic 252.00 2.84 232.56 2.52 Coal 149.10 1.68 135.73 1.47 Geothermal 55.44 0.63 58.15 0.63 Nuclear 31.08 0.35 45.89 0.50 Subtotal Domestic Production 8618.82 97.19 8865.50 95.10 Imports 260.82 2.94 370.65 4.02 Inventory changes (11.76) (0.13) (10.96) (0.12) Exports (3166.38) (35.71) (3361.75) (36.44) Others(spills, flaring,. . .) (143.64) (1.62) (167.67) (1.82) Total Internal Energy Supply 5557.86 5695.77 Energy Consumption Transformation Oil Sector 810.60 14.58 775.51 13.62 Electric Sector 896.28 16.13 921.86 16.18 Coke 6.30 0.11 6.63 0.12 Transformation Subtotal 1713.18 30.82 1704.01 29.92 End Use Sectors Industriala 1658.58 29.84 1654.50 29.05 Transport 1342.32 24.15 1430.98 25.12 Residential and Commercial 729.96 13.14 791.60 13.90 Othersb 113.82 2.05 114.68 2.01 End Use Subtotal 3844.68 69.18 3391.76 70.08 Total 5557.86 100.00 5695.77 100.00 aThe lack until very recently of any concern or measures of emissions' control by the energy sector, the transport sector and industry in general. bThe inefficient use of energy.
Table 8. Forest Demand Scenarios to 2010 (Scenarios Worksheet) Total Total Unit Total Total Area Area Cseq Cseq Cost C Cost Cost 2000 2010 Cseq/ha 2000 2010 Initial 2000 2010 Option (Mha) (Mha) (tonC/ha) (MtonC) (MtonC) ($/tonC) (Mdll) (Mdll)
Conservation Protected Areas 2.1 3.9 35 134 234 361 7.0 1,637 2,524 Forest Management 3.6 7.6 121 134 409 780 2.3 901 1,866 Imp. Woodstoves 0.1 2 1.3 0.1 3 10.0 1 26 (mill (mill Cseq/sl stoves) stoves) Afforestation Restoration Plantation 0.2 0.5 116.0 20 59 7.0 138 414 Plantations 0.0 0.5 39.5 0.0 18 7.0 0 128 Agroforestry N/A N/A N/A N/A N/A N/A N/A N/A Total 5.9 14.4 663 1,221 2,677 4,958
Table 9. Carbon Absorption and Emissions for Forests Temperate Temperate Tropical Tropical Coniferous Broadleaf Evergreen Deciduous Total Percent
Annual Carbon Balance(mTONc) 6.5 1.7 27.0 18.2 53.4 100% Intensity (ton/ha) 40 21 114 57 66 Activity Agriculture 1.8 0.5 2.9 2.8 8.0 15% Intensity (ton/ha) 72 36 136 59 74 Pasture 3.3 0.8 18.7 10.4 33.2 62% Intensity (ton/ha) 72 33 133 56 71 Other 1.4 0.4 5.4 5.0 12.3 23% Intensity (ton/ha) 16 10 72 56 24 Prompt Carbon Uptake 0.2 0.1 0.2 0.0 0.5 1% Intensity (ton/ha) 1.2 0.0 0.0 0.0 0.4 Committed Net Emissions(MtonC) 3.2 1.0 23.9 17.5 45.6 100% Intensity (ton/ha) 20 13 101 54 57 Stored Carbon (GtonC) 2.8 0.6 2.0 1.6 7.0 13,112% Intensity(ton/ha) 165 69 210 97 136
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