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Introduce biogas to save money, forests and mitigate global warming

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Added 25th April 2018 07:02 PM

Worldwide, biogas technology (also known as capture technology) has been extensively deployed. In Europe Germany is the largest Biogas producer. As a Microbiologist, I strongly support this naturally propelled, reusable, safe technology for producing energy for cooking.

Introduce biogas to save money, forests and mitigate global warming

Professor George B Kirya

Worldwide, biogas technology (also known as capture technology) has been extensively deployed. In Europe Germany is the largest Biogas producer. As a Microbiologist, I strongly support this naturally propelled, reusable, safe technology for producing energy for cooking.

By Professor George B Kirya

Forests are very important for our lives. They are used as home to millions of a variety of species. They protect the soil from erosion. They produce oxygen which we need to live, and they store carbon dioxide which helps to control the climate.

Forests are also vital to us for our lives as they provide us with food, shelter, and medicines, to mention but a few. They also purify the air we breathe and contribute to the formation of water in form of rain that we need to survive. It is, therefore, very important that everything possible is done to see how the earth's surface continues to be covered with forests and trees as much as possible.

In 2001 the Ministry of Water, Land and Environment of Uganda, through the National Association of Professional Environmentalists (NAPE), reported that the forest cover in Uganda was at about 21% of the country's total area, and about 70% of this was privately owned forest while 30% was under cover of government.

Forest soils are moist most of the time. But when there is no protection from the sun-blocking tree cover of leaves and branches, they quickly dry out. Trees greatly contribute to the formation of rain by helping the water cycle through returning water vapor to the atmosphere.  Without trees to fill this role, many forest lands become barren deserts. Lack of Forests generally creates shortage or lack of rain in an area or country as a whole.

Up to 30% of rain water that falls in the tropical forests is water that rain-forests have recycled into the atmosphere. Water evaporates from the soil and the forest vegetation condenses it into clouds and falls again as rain in a perpetual self-watering cycle. The more forest-cover we have in an area or in a country, the more recycled rains we would get. This is why, in places like the Entebbe peninsula and many mountains which used to be covered with thick forests, it used to rain almost daily, before a number of trees were cut down. The evaporation of the water also cools the earth's surface. Without the forest, it creates a drier, hotter climate in the tropics


According to Kayanja and Byarugaba of Makerere University in 2001, they stated that deforestation was real in Uganda and they predicted that Uganda's forest cover was going to be wiped out by 2040, if the deforestation was not properly dealt with.

In 2004-2005 the National Environmental Management Authority (NEMA) reported that Uganda's Tropical High Forest cover was reduced from 12.5% of the total land area to only 3%, a very big loss of forest.

In 2004, it was observed that the average annual deforestation was 1.76% of the available forest cover, and it was estimated that with that current trend of forest loss, in the next 20 years there would be no forest in Uganda (State of the Environment in Uganda (2004).

In 2015, Magala Richards of Makerere University stated that, the rate of deforestation in Uganda had skyrocketed and Uganda's forests were disappearing fast. He also predicted that at that rate, Uganda would not have any forest in the next 40 years. This situation also ushered in a number of environmental problems, such as devastating impacts of climate change and soil degradation, degradation of water shades, and food insecurithy due to very bad drought.

Causes of deforestation:

In 2004 NEMA said that Forest land was lost as a result of:

  1. Post-independent government policy to increase agricultural production between 1960 and 1970.

  2. Extensive woodlands which were cleared for livestock production. 

  3. There were policy deficiencies relating to the private sector and local communities over land tenure, over rights and resource management.

  4. The institutional structures to regulate environmental and forest management were weak due to inadequate funding for operations and development.

  5. Rural poverty which restricts the local community to invest in sustainable land use practices and lack of alternative livelihood options which resulted to continued dependence on forest resources.

  6. Using firewood as the only source of energy for cooking in the rural areas and charcoal used for cooking in most urban and peri-urban areas.

Around 90% of rural Ugandans use firewood to cook, which is an uphill struggle to reverse this alarming trend.


  1. Government degazetting forest reserves and land given to investors under the guise of increasing agricultural production, like Butamiira and Bugala Island forests.  Mabira Forest reserve is still at risk.

  2. Significant increase in construction of residential, commercial and Institutional buildings using burnt bricks which use tones of firewood.

  3. Timber for construction being on big demand, because builders rarely used metal poles.

  4. The majority of industries, being agro-based, like tea, processing sugar production, tobacco curing, bakeries, and fish processing; all using large quantities of firewood.

  5. Forests are cut as a result of growing urban places as land is developed for dwelling.

  6. Over-harvesting of trees, poor planning, weak regulations, higher population growth rate, and inadequate implementation, as drivers to the deforestation problem in Uganda.

  7. Dissemination of information and decentralization of Environmental Management, as proposed in government policy still lacking.

  8. Wide spread corruption, high level of impunity, inequitable sharing of forest resources and the limited government funding, making policies remain superficial and never implemented. 

  9. Breakdown in law and order between 1970 and 1980.

  10. Forests found on private land being degraded by the land owners who regard the forest as just a major source of income and potential agricultural and grazing land.

  11. Poles and timber uncontrollably extracted from forests.

  12. The high population growth per annum (Uganda Bureau of Standards 2002) caused expanding human settlement, both urban and rural, which has been responsible for the high rate of deforestation in Uganda as forests are cleared to give way to agriculture expansion and settlement.

Problems due to deforestration:

Deforestation ushered in a number of environmental problems which included: Soil degradation; degradation of water shade and food insecurity due to very bad drought.

There is loss of world species of Uganda's birds and mammals that live in forests but go away when they lose their habitats due to deforestation.

There is rapid changing and increasingly erratic weather patterns, where rains do not fall when they are supposed to, and draught leaves many farmers struggling to find enough food to feed their families. Poor rains always bring famine in countries.

Different animal species whose habitat is the forests, get threatened and run away.  Some start living close to human dwellings and this is what, to a large extent, has contributed to getting epidemics like Ebola, Murberg, Bird flu and Yellow fever.

Insects that dwell in either the canopy or forest floors are threatened by deforestation and migrate to other places or even new countries.

Birds that depend on flowers and insects, the tree-dwelling frogs and snakes, reptiles, mammals, that live on fruits and other mammals, suffer when the forest is destroyed or altered.

Urban and rural households, as well as Institutions like Schools and Hospitals, have started facing increasing energy shortages and high costs, and also spend more time collecting firewood or looking for charcoal

It is one of the greatest injustices to find that it is the world's poorest who will be the hardest hit by the global climate change and the effects of deforestation and destruction of the natural environment through deforestation.

Neither the natural re-growth of the forests nor the tree-planting projects, like when over 1000 people were given free forest reserve land to start planting trees recently, will ever keep pace with the damage for forest products.

In many areas of Uganda, one finds vast fields of land which go as far as one's eyes can go, looking bare with no forest and no trees but having only dotted shrubs. This has come as a result of the inhabitants in these areas cutting down all the forests and trees that existed, for firewood and production of Charcoal.

One finds heaps and heaps of sucks full of charcoal piled-up on the sides of the main roads in this country, waiting to be ferried to the towns and main city. Lorry-loads full of charcoal bags are found on our high-ways transporting charcoal, and sometimes firewood to the urban dwellers. The other day, Ugandan trucks were arrested while ferrying charcoal to Kenya, where there is a big market of charcoal selling, Kenya government having banned production of charcoal in the country. This is atrocious because those ferrying the charcoal have never planted a tree to replace the ones they had cut!

The use of firewood and charcoal for cooking has contributed a lot to the deforestation and its dangerous effects in Uganda.

Unless an easily accessible and affordable source of energy for cooking is introduced, especially to the rural dwellers in this country, deforestation will continue until all available forests and trees are cut down to provide firewood and for production of charcoal. Already, there are areas which are witnessing severe shortage of fuel to use for cooking because of lack of trees in the area. The climate in this country is also complaining bitterly.

Government put the Rural Electrification Agency (REA) in place to ensure that rural electrification, which, in most cases is not commercially viable, is accelerated to achieve the set targets. This has, however, not worked because of the cost of electricity.

Electricity is contributing only 1.4% to the natural energy balance, because most people in the rural area find the electricity tariffs too high. The same applies to the urban dwellers who decided to use charcoal for cooking, because they also find electricity too expensive to use an electric cooker. Uganda has one of the lowest per capita electricity consumption in the world.

UMEME with the approval of the Electricity Regulatory Authority (ERA) raised the electricity tariffs by up 11% in the first quarter of 2017, despite the population feeling that the cost was already too high. The cost has been increased by over 22% over the past three years.

Cooking with solar energy or the practice of using the sun as an energy source to cook food is gaining traction around the globe, as a low-cost way to prepare meals. But because it requires special solar cooking equipment, which is quite expensive, it is not at all suitable for Uganda's urban areas.


Worldwide, biogas technology (also known as capture technology) has been extensively deployed. In Europe Germany is the largest Biogas producer. As a Microbiologist, I strongly support this naturally propelled, reusable, safe technology for producing energy for cooking.

Biogas is a mixture of gases produced by microorganisms when livestock manure, like cow dung, pig waste, chicken droppings, human excreta and other biological wastes, are allowed to ferment in absence of oxygen (anaerobically) in a closed container called a Digester. The major constitution of Biogas are: Methane (CH4) 60%; Carbon dioxide (CO2) about 35%;  with small amounts of water vapor, Hydrogen Sulphide (H2S); Carbon monoxide (CO) and Nitrogen (N). These are the odorless, clean gases which are safely combustible and are used for cooking and lighting.

The digested mixture of liquids and solids from the Digester, called bio-siurry and bio-sludge, are very good for use as organic fertilizers for crops.

In situations of highly deforested and pressurized firewood resources which are enormous, like in Uganda, Biogas, which does not require firewood, saves forest resource.

Biogas systems integrate very well with dairy farming systems. Manure slurry (cow    dung or chicken droppings, pig droppings, added in water) is fed into a large tank called the Digester where microorganisms (bacteria) reduce the complex organic matter into Methane gas and other organic compounds, mentioned above, which are directed into the kitchen cooking stove. One or two cows using zero grazing are enough to give a home Biogas they can use continuously.  This would also be useful if a few cows are introduces in many of the schools and Hospitals to provide cow dung which is used in the Digester to produce Biogas for cooking and lighting.

Once primed and fed daily with manure slurry the Digest produces methane gas daily.  The more manure slurry is fed into the system the more gas is produced.

Biogas is one of the cheapest and cleanest form of renewable energy to be used for cooking, lighting and heating purposes in a home, a School and other Institutions. .

Biogas is being used in a number of countries of the world for cooking, which greatly reduces pressure on the use of firewood and charcoal.

Benefits of biogas:

Biogas has enormous potentials, especially in countries that rear cattle and, therefore, have plenty of cow dung they can use to produce, on a daily basis, manure slurry for the Digester that produces the methane Biogas. This, as a result, is particularly a useful system in the country's economy where it can fulfill several end uses.

It is clean with no smoke; ignites quickly and enables effective cooking; it is cost-effective (no need to purchase firewood or charcoal)

The Biogas is very useful as a fuel substitute for firewood, charcoal and electricity.

Biogas systems in agricultural communities can increase agricultural productivity. All the agricultural residue and the dung generated within the community is available for the anaerobic digestion. The byproduct from the Digest called the Manure Slurry is returned to the land as very rich fertilizer which is rich with fertilizers. This organic waste, after the anaerobic digestion, has superior nutrient qualities over the usual organic fertilizers, the cow dung or chicken droppings.

In India, there are about 3 million biogas plants of differ sizes supplying around 30 million households.

Biogas technology will predominantly offer an excellent energy source for rural Uganda. It has the potential to cater for the needs for cooking and basic fuel. Rural areas are in a better position to utilize local resources like organic waste and cow dung for the generation of biogas.

Government's consideration:

Going for renewable energy resources is an excellent workable option to the deforestation Uganda is facing, through using firewood and charcoal. It could be the only way forward since electricity has proved to be too expensive for over 98% of the rural dwellers to use.

Biogas systems offer an integrated system that lends itself to a rural setting. The Digester plants can be maintained with a variety of organic residue for humans, animals, crops, and domestic food waste.

China considers biogas production an effective and natural use of natural resources in rural areas. Biogas production not only provides energy but also offers environmental protection and improvement of hygiene and is an important modernization of agriculture, through providing the effluent called Manure Slurry used as clean fertilizer.

The liquid and solid from the Digester is a treasure of valuable biological resources. They include nutrients for crops, such as Nitrogen (N); Phosphorus (P); Potassium (K); and trace elements that stimulate seed germination and growth.

It is important, therefore, that government takes cognizant of these facts and start taking action in the direction of producing alternative cooking energy in rural areas with the help of Biogas, a well-researched and cheap renewable resource.

This requires steps to bring awareness among the public about the benefits of using Biogas. This technology should be adopted, not only in domestic households, but also in schools and even upcountry hospitals. The trend of Private, Public Partnership, especially with countries that are already using biogas, almost routinely like: India, China, Australia, Nigeria, Rwanda, Germany and so on, should be explored. This will bring about the shift we want to save the remaining forests and trees in Uganda, before they are totally destroyed through firewood and charcoal, among other causes.

The writer is a Professor of Medical Microbiology; former Vice Chancellor Makerere University and former Uganda's High Commissioner to the UK




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