Arusha — A recent study visit to Maasai land in Arusha revealed that people who keep large numbers of cattle contribute to global warming and therefore to climate change significantly. This refers particularly to local people in Maasai land, Mwanza and Mara Regions in Tanzania.

Needless to emphasize, climate change that is caused by global warming is life-threatening. Scientists caution that climate change will cause serious starvation among other disasters because dry and hot areas will become drier and hotter. In the end, land in such areas will become less productive as regards agriculture.

Water bodies particularly the ocean will fill up and overflow to drown human settlements that are located on low lands. Then the water will rise to reach higher areas say in Arusha. It sounds like a dream. But it is real.

The reality is that cattle manure produces a gas that influences the earth to heat up thereby causing the huge reserve of frozen water on the earth's poles to melt into liquid and fill up the oceans. Cattle manure produces a gas known as methane.

The earth heats up because methane has a tendency to trap heat that would otherwise be allowed to escape higher up into the atmosphere. The gas traps heat because it forms a layer in the atmosphere that allows heat from the sun to penetrate and enter the earth's sphere but it prevents heat from the earth to go through the layer to altitudes that are higher up in the atmosphere. The heat from the earth is the same heat from the earth surface. The difference is that the heat from the earth reaches the layer of methane after it has bounced from the earth's surface.

By the way, the layer of the gas from cattle manure easily spread beyond national atmospheric boundaries thereby trapping heat even in neighbouring countries that don't emit methane into the atmosphere. In the end, a layer of gas from distant countries is formed covering atmospheric surfaces of many countries. It suggests that global warming and climate change is a concern for everyone on earth

At some point, scientists became curious to know why the layer of methane allows heat from the sun to penetrate the layer of methane while the same layer prevents the same heat to penetrate the layer after bouncing from the earth's surface.

Scientists learned that the medium on which heat travels become weak after it bounces from the earth's surface or from any surface for that matter. As a result, the weak medium and therefore the heat it carries from the earth's surface cannot penetrate the layer of methane to escape from the earth.

The scientists have coined the term "Greenhouse effect" to mean the warming effect of the earth as a result of the heat being trapped by gases such as methane. Incidentally, there are many types of gases that contribute to global warming and climate change.

The term greenhouse effect refers to experiments which scientists carried out at some point in time to determine characteristics of the medium on which heat travels. They conducted experiments using enclosures that are used for raising plants. The enclosures are known as greenhouses. In particular, the scientists aimed to develop a methodology to establish and maintain localized environments that are situated in cold areas where they can grow plants that prefer warm weather. Therefore, the terms greenhouse effect, global warming as well climate change have nothing to do with the green houses for flower farms that are located along the Arusha Moshi highway in Arumeru District. It is misleading to say that the greenhouses in Arumeru District or anywhere else cause global warming or climate change.

On a related matter, the term greenhouse effect is often wrongly associated with destruction of Ozone which is a natural layer of a gas made of oxygen in the atmosphere. Ozone filters harmful substances from the sun. But certain gases that are produced by human activities destroy the Ozone thereby allowing harmful sun rays to go through the layer thereby causing skin cancer among victims on earth. Gases that cause destruction of the Ozone layer are different from those that cause global warming. Therefore, destruction of ozone layer and global warming are completely different phenomena.

On the other hand, the seemingly harmful gases such as methane are useful to human beings. Methane can become an important source of energy particularly in Maasai land where people keep large numbers of cattle. Energy based technologies are available to use methane as a source of energy for heating, boiling and lighting. The most common is the biogas technology.

Biogas technology engineers construct plants that allow cattle manure and water to be mixed in order to produce methane readily which is then trapped in pipes. Then the gas is tapped for cooking and lighting. But the engineers jockingly say that technology is not yet available to trap methane which comes directly from the cattle when they puff gas through the anus. Incidentally, cattle produce more methane directly from the anus than from their dung.

Numerous institutions and individuals in Arusha provide biogas technologies for use by households as well as institutions. The more established institutions in Arusha that provide biogas technologies include the Center for Agricultural Mechanization and Rural Technologies (CAMARTEC), Kampuni ya Kusambaza Tekinolojia (KAKUTE), Women Development for Science and Technology Association (WODSTA) and the Evangelical Lutheran Church of Tanzania (ELCT).

Biogas technology is an important path for developing alternative sources of energy to avoid destruction of the environment that is characteristic of petroleum products such as diesel. The most limiting factor concerning use of biogas technology is the limited availability of inputs such as cattle dung also known as feed stock. It suggests that the biogas technology has great potential to make the large numbers of Maasai cattle a significant source of renewable energy rather than a cause of global warming.