SUMMARY

In accordance with Article 4.1 a of the United Nations Framework Convention on Climate Change, all parties to the Convention are requested to update and report periodically on their national inventory of anthropogenic emissions and removals of greenhouse gases.

There is no primary fuel production in the Republic of Mauritius. Since all fuels are imported, the Republic is fully dependent on market vacillation and price fluctuation. Secondary fuel is imported for local consumption. Except for international marine and air bunkering, fossil fuel is not exported.

Greenhouse gas emissions and removals by sinks have been calculated for the year 1995, using the 1996 Intergovernmental Panel on Climate Change IPCC guidelines for the Preparation of National Communications, inclusive of all the six identified items.
 

Energy-related activities are the most significant contributors of greenhouse gases. Energy is produced mostly through the combustion of fossil fuels such as petroleum, natural gas and coal, which accounts for 90% of the total with the remaining 10% from hydropower and biomass.
 
 
 
 
 
 

INTRODUCTION

Climate Systems and Radiative Forces

Solar energy is the main source of power that drives the climate systems of the earth. About 70% of the short wave solar radiation is absorbed by the earth’s surface, oceans, ice caps and the lower atmosphere known as the troposphere. The rest is re-radiated into space. The absorbed short wave solar radiation is reflected back into the atmosphere in the form of out-going long wave infrared radiation. Some atmospheric gases, existing naturally in the atmosphere and known as greenhouse gases GHGs, can absorb or "trap" the outgoing long wave radiation emitted from the earth and re-radiate it back to the earth, thus keeping the earth and its atmosphere warmer than it should have been. In the long-term a balance is reached between the absorbed short wave solar radiation and the outgoing long-wave terrestrial radiation. The climatic and radiative balance, restored through this mechanism, resulted in a higher temperature on the earth’s surface thus permitting life to exist on the planet. Without the presence of these greenhouse gases, planet Earth would have been uninhabitable.

Greenhouse Gases

The naturally existing greenhouse gases are:

• water vapour H₂0
• carbon dioxide C0₂
• methane CH₄
• nitrous oxide N₂0
• ozone 0₃

INVENTORY PROCESS

Methodology and Data

The emission estimates, presented in this initial communication, were calculated according to the 1996 IPCC Revised Guidelines for National Inventory of Greenhouse Gas, to ensure that the emission inventory is consistent and comparable across sectors and between Parties. A copy, of the IPCC guideline worksheets and reporting tables, is appended in the annexes. The IPCC guidelines have been followed to the letter and all default values provided have been used.

Both the top-down and bottom-up approaches have been used for the preparation of this national inventory of greenhouse gases.

Sources of data

The data for energy production and consumption activities are based on the latest information and were obtained from the following sources:

• Energy balance for base year 1995
• Baseline scenario 1995-2020
• Central Statistical Office
• State Trading Corporation
• Central Electricity Board
• Bulk Bitumen Company Ltd
• Mauritius Marine Authority
• Mauritius Sugar Authority
• Ministry of Agriculture, Fisheries & Co-operatives - Forestry Department

Organization

The National Inventory has been organised into six parts corresponding to the six major source categories, as described in the IPPC 1996 Guidelines.

I. Energy Activities

•  Energy Industries
• Transport
• Manufacturing Industries and Construction
• Other Sectors
• Other

III. Solvent and other Product Use

IV. Agriculture

• Enteric fermentation
• Manure management
• Agricultural Soils

• Managed lands
• Grassland Conversion
• Managed Forests and
• Clearing Forests

• Solid waste disposal on land
• Waste water handling

Uncertainty and limitation of emission estimates

The uncertainties and limitations, as per IPCC guidelines, will be reflected in this chapter.
 

EMISSIONS

Energy

GHG emissions were mainly from two fossil fuel types: liquid and solid fuel categories. Liquid fossil fuels consisted of gasoline, jet kerosene and other kerosene, gas/diesel oil, liquefied petroleum products Lpg and lubricants. Coking coal was the most commonly used solid fossil fuel.

The total amount of GHG emissions for the energy sector was 1835.338 Gg, out of which 1736.852 Gg is directly from C0₂ emissions. C0₂ emissions, from fossil fuel, represented 99.9% of total emissions of carbon dioxide and 94% of all greenhouse gas emissions.
 
 
 

Public Electricity

The Republic relied heavily on fossil fuel for the production of electricity since other sources were limited. The resulting C0₂ emission from this activity totalled 655.575 Gg, representing 38% of total C0₂ emissions.
 

Transport

Road transport is the only available means to cater for passenger and freight displacement. The transport sector consumed 86 536 t of gasoline and 119 287 t of diesel, thus producing of C0₂ emissions of 644.977 Gg which represented 37% of total C0₂ emissions.
 

Manufacturing and Construction Industries

The major industries, in the Republic of Mauritius, comprised the following:

• Sugar
• Textile
• Tobacco
• Stone crushing and block-making and
• Beverages and allied industries

Residential / Commercial Sectors

Energy needs in the residential/commercial sectors were met mainly from the following sources:

• Kerosene
• Lpg
• Charcoals
• Fuel wood and
• Electricity

In 1986 the Government promoted the use of Lpg, as an alternate source of energy, by reducing up to 50% customs duty on its import. All appliances, using Lpg, were exempted from all taxes. A sharp increase in Lpgconsumption was noted and reached 30 174 tons in 1995. This trend is being maintained and future Government policy is to phase out completely the use of kerosene, fuel wood and charcoal.

CO₂ emissions from these two sectors were estimated to be 148.389 Gg and represented 9% of the total emissions.

                           Sectoral CO₂ emissions Gg based on Fuel Types
 

Non-CO₂ emissions from fossil fuel combustion

Apart from CO₂ emissions, fossil fuel combustion produces other greenhouse gases, such as methane and nitrous oxide, and also the photochemically important gases such as oxides of nitrogen, carbon monoxide and non-methane volatile organic compound, which are all products resulting from incomplete combustion. Amounts of these non-CO₂ emissions vary depending on types of fuel and technology used, and existing pollution control practices.
 

Sulphur Dioxide Emissions from fossil fuel combustion

Varying proportions of sulphur are found in fossil fuels and during their combustion sulphur dioxide, which acts negatively on the greenhouse effect, is emitted. The amount of SO₂ emissions depends on the sulphur content of the fuel, the sulphur retention in the ash, the abatement efficiency and other factors. Local figures provided by competent authorities for sulphur content of all imported fossil fuels have been taken into consideration in the calculations together with default values provided by IPCC.
 

SO₂ emissions in 1995 were estimated at 13.369 Gg and details are presented in the summary table. Electricity production accounted for more than 66% of total SO₂ emission.
 

Carbon stores in products

Bitumen and lubricants have been imported in l995 for non-energy application sectors such as road construction. The carbon stored has been estimated at 17.184 Gg.
 

Fugitive Emissions

Coal mining, handling, production, processing, transport and use of oil and natural gas as well as the non-productive combustion and conversion of crude petroleum into a variety of sub-products are associated with fugitive emissions are not carried out in Mauritius. Therefore fugitive emissions from fuels are nil.
 

Memo items

International bunkers

International bunkering accounted for 670.285 Gg of CO₂ emission in 1995 and the details are given in the table below.
 

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INDUSTRIAL PROCESSES

Greenhouse gases are also produced, as residues of various non-energy related activities. These gases are emitted directly from the process itself, not as a result of energy consumption during the process.

The production processes, of interest to the Republic of Mauritius, are:

SOLVENT AND OTHER PRODUCT USE
 

Solvent and other chemical products can produce emission of some greenhouse and photochemically important trace gases. Emission from this sector has not been calculated due to lack of sufficient data.

 

AGRICULTURE

The Republic of Mauritius depends almost entirely on imports for its main basic foodstuffs, except for vegetables. It has a very small livestock population. There is no cultivation of rice, no prescribed burning of savannas or field burning of agricultural residues. Mauritius is concerned with only enteric fermentation, manure management and agricultural soils on a very small scale only. Emissions from animal production and from animal waste management system are negligible.

The resulting methane emissions is summarised below:
 

Livestock type	Population	Enteric Fermentation	Manure Management	CH4 emission Gg
Dairy cattle	8500	306.00	8.50	0.314
Non Dairy cattle	8000	256.00	8.00	0.264
Sheep	1500	7.50	0.31	0.007
Goats	10000	50.00	2.20	0.052
Horses	500	9.00	1.10	0.010
Mules & Asses	25	0.25	-	-
Swine	12000	12.00	24.00	0.036
TOTAL		640.75	44.11	0.683

 

Agricultural Soils

Nitrous oxide can be produced from agricultural soils through various activities such as application of synthetic fertilizer, animal waste, nitrogen-fixing crops, crop residues and through indirect emissions from the atmospheric deposition. The N₂0 emissions from these activities have been estimated at 0.403 Gg. There is no N₂0 emission from the cultivation of histosols.
 

LAND USE CHANGE AND FORESTRY

A wide variety of carbon and nitrogen trace gases are either emitted or absorbed in the biosphere. Any changes in the biosphere, through land use changes and forestry activities will modify the natural balance of these trace gases both in emissions and uptake. On the global scale the human activity which most affects the biosphere is deforestation, especially in the tropical region.

In this sector, the calculation of emissions focuses on four activities which act either as sources or sinks:

• abandoning of managed lands
• grassland conversion
• managed forests
• clearing forests

Abandoning of Managed lands

Since land area in Mauritius is very limited, intensive agriculture is practiced on all suitable land and there is no abandoning of managed lands.
 

Grassland conversion

Under this item it is required to estimate the net CO₂ emissions resulting from the conversion of grasslands into cultivated lands during the last 25 years up to the inventory year. Grassland conversion has been negligible, in the Republic, as there has been practically no grassland, which has been converted to cultivated land.
 

Managed forests

Forests are critical components of the climate system. Their potential for sequestering greenhouse gases is enormous, and they act as an additional "reservoir" for CO₂ emissions. Prior to the 16^th century, the whole island of Mauritius was covered with dense forests, mainly of tall, slow-growing trees. Unfortunately in the late 18^th and early 19^th century, most primary forests were cut down as land was converted for agricultural purposes. Forests were cut for timber to build boats and houses, for fuel wood and particularly to clear land for cane cultivation. Today less than 1% of the area of Mauritius is under some sort of native vegetation.

In the National Inventory assessment survey for Mauritius, the CO₂ uptake from changes in forests and other woody biomass stocks was analyzed and the results presented in the table below.
 

Carbon Uptake by Forests
Plantations	Area kha	Annual Growth Rate tdm/ha	Annual Biomass Increment ktdm	Carbon Fraction  of Dry Matter	Total Carbon Uptake Increment ktc
Conifers	12.55	5.25	65.924	0.45	29.666
Casuarina	0.65	6.30	4.095	0.45	1.843
Nature Reserves	9.20	1.30	11.960	0.45	5.382
Exotic Scrubs	34.54	2.60	89.804	0.45	40.412
Total	56.94				77.303

Non Forest Trees Conifers

Number of trees = 600,000
Annual growth Rate = 2.916 x 10³ kt dm
Annual Biomass increment = 600 x 2.916 x 10³ = 1.749 ktdm
Carbon Fraction of Dry Matter = 0.45
Carbon uptake Increment = 1.749 x 0.45 = 0.787 ktc

Carbon Uptake

Total Carbon uptake Increment = 77.303 + 0.787 = 78.090 ktc
The annual biomass carbon removal is 17.749 ktc/yr
Thus the net CO₂ flux is 221.36 Gg
 

Forest clearing

The conversion of forests to permanent cropland or pasture is insignificant in Mauritius since the land area is small and limited. There is no remaining forestland that could be converted to cropland.
 

WASTE

Methane is one of the principal sources of greenhouse gases contributing to global warming, second only to carbon dioxide. Methane emissions originate from several sources including anaerobic decomposition of organic wastes in solid waste disposal sites, in sludge and residual solid by-products. In this sector, methane emission is calculated from solid waste disposal sites and from domestic and industrial waste water handling.
 

Solid waste disposal site on land

Anaerobic decomposition of organic matter in solid waste disposal sites by methanogenic bacteria results in methane emissions. The method used to calculate methane emission depends on the amount of waste disposed, the fraction of degradable organic carbon, the amount, which actually degrades, and the fraction of methane in landfill gas. It is also assumed that methane is released in the same year that the waste is placed in the disposal site.
There is no sanitary landfill at present in Mauritius. Solid wastes are disposed of in about ten open disposal sites. No accurate data on the quantity of waste collected is available. In 1993, Scott Wilson Kirkpatrick, a consulting firm which prepared the "National Solid Waste Management Plan", estimated that the domestic waste produced per head is 0.6 kg per day. Since there has been a lot of waste burning in the open disposal sites, it is estimated that only 20% of the domestic waste disposed of, could be considered to be in the landfill sites. The calculations IPCC worksheet 6-1 have shown that the net methane emission from domestic solid waste disposal is 3.406 Gg.
 

Domestic waste water handling

Domestic waste water includes all liquid wastes from factories, hotels, restaurants and residential premises. Only parts of two urban districts of Port Louis and Plaines Wilhems have sewage facilities, representing only 20% of the population. At present all our waste water treatment works comprise of preliminary treatment, that is screening, removal of grit and disintegration of solids and then the effluents are disposed of through sea outfalls. There is no anaerobic treatment of sewerage and so no production of sewage sludge. The remaining 80% of the population use septic tanks and on-site disposal systems.

Hence, no estimates of methane emissions from domestic waste water have been made.
 

Industrial Waste Water

Agro-industries and dye houses essentially produce the industrial waste water, and they are largely untreated. Many factories discharge their waste water into the subsoil. The sugar factories use their effluent for irrigation. In some cases, effluent is treated prior to disposal but most treatment plants provide for biological treatment by an oxidation process and a correction of pH. There is no anaerobic treatment of effluent. Thus, estimation of methane emission from industrial waste water has not been carried out.
 
 

CONCLUSION
 

Any adaptive or mitigation measure to be taken for the Republic of Mauritius, will have to be in the field of either electricity production or transportation. Increase in energy-efficient use of equipment in the manufacturing sectors will not only cut down cost of production but will also contribute to a decrease in GHG emission.
 

ANNEXES