Climate change and global warming pose threat to ecosystems

This article on climate change and global warming starts with a reference to what the scriptures state. When all was set to put humans on earth in the creation process, two gases - oxygen and carbon dioxide - were considered essential to sustain life in humans and plants.

Adam was instructed to nurture and protect the environment as the scriptures inform us. Plants make and release oxygen and humans use oxygen to sustain life. We use oxygen to generate carbon dioxide, which plants use to make oxygen and sugar.

Greenhouse gases

Other gases, for example, methane arise from different sources. Carbon dioxide and methane are the main gases that make this world stay warm because they can absorb heat. Carbon dioxide and methane are known as greenhouse gases. But when greenhouse gases are in excess in the air they cause global warming.

All living things, including microbes, birds, mammals and plants, generate waste products that must be removed from their bodies. Humans and other mammals release waste products in form of faeces, urine and carbon dioxide.

Sewage systems, where available, handle feces and urine to specific collection or disposal sites known as septic tanks. Humans are prone to generate rubbish or garbage from their homes. In towns and cities rubbish or garbage is collected and taken to landfills.

Our ability to manage sewage and garbage and pollutants from where we live or work, factories and cars is of paramount importance. We have the capability to develop control measures, which would save the environment and turn sewage and garbage for useful purposes. You will be surprised that each day a human being excretes about 125 grams of faeces and 1,400 millilitres of urine.

These two products are generally termed waste because they arise from the food we eat and the liquids we drink. Tanzania with a population of 56,784,974 inhabitants produces 7,098,121kg of faeces and 79,500,363.6 litres of urine per day. How is this colossal volume of waste disposed of? Because most people in Tanzania live in villages, where piped water and flush toilets are in most cases unavailable, much of the voided urine and faeces is stored in latrines. Urine and some of the dissolved faeces generate greenhouse gases. Urine and faeces could percolate through the latrine and contaminate surrounding rivers and streams and may in that way spread diseases.

Flush toilets

Flush toilets are common in towns and cities, where after flushing a toilet the waste is driven through a sewage system into a septic tank facility, where the waste is broken down by bacteria. Ideally, sewage must undergo treatment in a wastewater treatment plant before it is disposed of, for example, before it is released into lakes, the sea or as fertiliser or other purposes. This procedure is done in the western world. In the developing world, sewage treatment has not been fully realised. After sewage has undergone treatment sewage sludge and a nutrient-rich-digestate remain behind and can be used to generate biogas, whereas the digestate is fit as land fertiliser.

Sewers emit primarily methane, carbon dioxide and sulfur dioxide, which are greenhouses gases. Because this article is on global warming and climate change it is also necessary to explain some specific terminologies. At about 20 to 30km above the earth surface is found the ozone layer. Ozone is derived from oxygen. Ozone layer absorbs most of the sun’s ultraviolet radiation, which is harmful to living things on earth.

Damaging the ozone layer

Certain gases, including carbon dioxide and methane, can damage the ozone layer, when they exceed certain concentration in the air. The heat that ultraviolet radiation emits on earth is absorbed by greenhouse gases such as water vapour, methane and carbon dioxide.

When this happens we are protected from the harmful effects of ultraviolet radiation such as the development of cancer. So, before we condemn methane and carbon dioxide as bad greenhouse gases we must give them credit because they are able to keep the world warm.

The problem arises, when too much carbon dioxide and methane accumulate in the air since they absorb much heat which produces global warming. Before things started going bad in the atmosphere after the industrial revolution the atmospheric methane concentration was 0.0017 per cent. That of carbon dioxide was 0.0360 per cent. Methane is 30 times more effective in trapping heat than carbon dioxide. In 2014, the concentration of carbon dioxide was 81 per cent and of methane was 11 per cent. This is a phenomenal increase.

Hard Statistics

Some hard statistics on cars on the road is baffling: The number of cars (in millions) in selected four countries is as follows: Canada 34 (by 2015), USA 250 (by 2015), Germany 62 (by 2015), Japan 68 (by 2011), China 300 (by 2015). By contrast Kenya had 0.028 (by 2016), while Tanzania had 1.8 registered cars (by 2011). In total, there have been about 716 million cars emitting at the exhaust methane, carbon dioxide, nitrous oxide into the atmosphere. These figures demonstrate the role of cars in air pollution.

Climate change and global warming have been forming for about 150 years, when the industrial revolution became entrenched, but because the process is slow it has taken long to manifest.

The first country to industrialise was Britain and by 1850 it was recognised to be leading others. The industrialisation of China was achieved in 1950, Japan 1900 and US 1870-1900. Of course, there are many good effects of industrialisation.

The bad effects are air, water and soil pollution, which produce climate change and global warming.

Extreme weather conditions

In the past five or more years, these effects have manifested as extreme hot and cold weather and floods, hurricanes and earthquakes. Tanzania has had its share of the calamities: repeated flooding in Coast Region, earthquakes in Kagera and windstorms in Mtwara. All over the country agricultural production is under threat. By extension our food security is being tested.

As a basic science teacher, I am concerned about the evolution/mutation of the current disease - causing organisms that may attempt to cope with global warming and develop defence mechanisms that can resist different medications that we provide to treat patients. Some of the organisms may mutate completely and become new and unknown to our bodies. If that happens, I think a few of us will survive their onslaught.

A form of resistant TB

Currently, we have a form of TB that has defied all tuberculosis treatment modalities since 1900. While discussing this problem recently with a scientist on tuberculosis I alluded to her that my prediction is that the recalcitrant TB could have arisen from the effects of global warming because the TB organism is literally in contact with global warming in the lungs. She smiled; we shook hands and parted ways.

My experience living in Kilimanjaro Region for more than 60 years is that never before have I experienced such harsh weather conditions as in the past five years. The region enjoys relatively warm weather throughout the year. Evenings are usually cool. Moderate rainfall is expected in February-March.

This situation has manifestly changed in the past five years. Currently it is excessively hot, hotter than Dar es Salaam. The good rains have not fully arrived. Some areas have been affected by hurricane winds. Some little rain came with terrible storm and lightning. The vegetation is defoliating. It is predicted that in the next 25 years there will be no snow on the top of Mt Kilimanjaro. The mountain will be like an anthill. It is a pity, as that will mark the end of tourism!

Trends in weather conditions

Looking at current trends in climate and weather changes one can ask a provocative question: who and how will the excessive greenhouse methane, carbon dioxide, nitrous oxide and carbon monoxide gases be removed from the atmosphere?

Advances made in chemistry, physics, astronomy and meteorology, etc in the industrialised world can be put in place to device a system that will remove excessive levels of greenhouse gases, especially methane and carbon dioxide from the atmosphere. From a Tanzania perspective, Tanzanians should adopt all measures that would mitigate further global warming and climate change. We should reduce or eliminate methane and carbon dioxide from landfills and septic tanks. Tree felling and logging should be prohibited.

New industrial facilities

All new industrial facilities that are built should operate by enforceable gas emission rules and waste generated by such facilities should follow laid down disposal procedures. We must recycle garbage, feces, urine etc. Some countries are generating electricity from their urine.

In short one solution is that we must be proactive and recycle waste matter as much as we can. To me the word waste is a misnomer. Hence, climate change and global warming is neither a mirage nor a hoax. Yes, we can rewind the clock.

The author is a basic science teacher with peripheral legal-political interests.