Regions around the globe are defined by their climate. Different areas around the globe experience different climatic conditions and these define how different species survive. Species have adapted to the climatic conditions in the area they live and have managed to survive for centuries, reproducing and finding food and water for survival in the environment around them. All this is about to change. In fact, changes have already begun.
The National Geographic Society defines climate change as the long-term shift in temperature and typical weather patterns which can be identified by changes in the mean and/or the variability of its properties using statistical tests. The Intergovernmental Panel on Climate Change (IPCC) refers to it as any climatic change that occurs over time, whether it is as a result of natural variability or human activity. Whilst the United Nations Framework Convention on Climate Change (UNFCCC) argues that it is change attributed directly or indirectly to anthropogenic activities which have brought change to the global atmospheric conditions adding on to the natural climate variability over a long period of time. The climate is an important aspect of the environment. It defines the temperature patterns, precipitation patterns, wind direction and force which further affect different aspects of the environment tempering with life supporting elements such as water, forests and land for produce. Climate change has a ripple effect on the environment and is proving to be a life threatening phenomenon if it continues unabated. Climate change related events are on the rise and this is changing peoples’ lives and way of living. Changes in land cover and land use attributed to climate change are being noted, lives are being lost, disease outbreaks are being experienced, infrastructure is getting destroyed, farm lands are being swept away in floods and some burnt in veld fires.
Extreme weather events are a critical element of climate change. An increase in the frequency of extreme weather events such as cyclones, tornadoes and floods is being recorded. These events destroy the land by causing land degradation through gulley formation, infrastructural destruction and farm land destruction. It leaves a population homeless, stranded with no safe and sufficient food or water to drink. No workplaces to go back to and no hospitals to seek medical attention from. Cyclone Idai which hit Zimbabwe and Mozambique in 2019 is one such event that left people exposed to such devastating and life changing scenarios. Road networks were destroyed and so were homes and schools.
Veld fires cripple ecosystems, biodiversity in forests and open land is lost, animals die and valuable native plants are burnt, some which might never be able to sprout again. Veld fires affect soil fertility and can trigger the proliferation of invasive species especially those which favour harsh conditions such as the Opuntia fulgida in Gwanda. The released carbon dioxide and other greenhouse gases from the burning contribute further to global warming and also pose a risk to the humans in the surrounding areas especially those with pre-existing health conditions such as asthma. Millions worth of property is lost and the environment is degraded. The destruction of forests and farmlands by these fires threaten the food security of a population leading to cases of malnutrition being recorded. Natural tree, herbs and plant medicines get burnt in the fires leaving the humans exposed and vulnerable to different health ailments which can threaten their lives without the medicinal herbs to treat them.
The proliferation of invasive species attributed to climate change threatens agriculture and food security. The changes in temperature, precipitation and frequency of extreme events influence specie distribution and growth. Invasive alien species favor harsh conditions and survive better outgrowing the native plants. Once fertile land or grazing lands are invaded and their productivity levels are reduced. People are then forced to change their way of survival. Most small-scale farmers are being forced to neglect farming to venture into small scale mining or migrate to the big towns in search of a means for survival. Hunger and malnutrition is becoming a norm in the agriculture depended rural areas of countries in the Sub-Saharan Africa.
Another climate change phenomenon that is tempering with the agricultural production is drought. Droughts are being experienced more often and these are attributed to climate change. Temperatures have warmed over the past century and the prevalence and duration of droughts have increased especially in the dry and relatively dry areas. It has been envisaged to become drier with the continual increase in temperatures and atmospheric warming. Zimbabwe one such country which is on rain fed agriculture and in 2018-2019 it was hit by one of the worst droughts in decades, leaving over 7.7 million people living with food insecurity. According to UNICEF, nearly 1 in 3 children in Zimbabwe under five are suffering from malnutrition, while 93 per cent of children between 6 months and 2 years of age are not consuming the minimum acceptable diet. The incidence of Pellagra, a deadly disease linked to micro-nutrient deficiency is also on the rise.
According to the National Geographic Society, research confirms that climate change is altering the structure and function of aquatic and terrestrial ecosystems. The rise in temperature, changes in seasonality, increased frequency and magnitude of extreme events, as well as the acceleration of the hydrologic cycle will shift ecosystem types, process rates, and connections to other ecosystems. A noted example is that of Lake Tanganyika which has been known to support a highly productive pelagic fishery that is currently producing 25–40% of the animal protein supply for the people in the surrounding countries. A rise in surface-water temperature has increased the stability of the water column due to the regional warming patterns since the beginning of the century. A regional decrease in wind velocity has contributed to reduced mixing, decreasing deep-water nutrient upwelling and entrainment into surface waters. Findings show that the carbon isotope records in sediment cores suggest that primary productivity may have decreased by about 20%, implying an estimate of 30% decrease in fish yields. If overall fish yields decrease it means fish availability on the market will be reduced, thus food shortages. The community that survives on fishing will be affected as it will no longer have a source of income for the sustenance of their lives leading to increased cases of poverty and food insecurity. The economies will also suffer.
Climate change is influencing disease patterns, with the increase in temperature and occurrence of flash floods and cyclones, environmental conditions suitable for vector breeding are formed. Studies have shown a positive correlation between climate change and increase in mosquitoes and malaria cases in Africa, in the Eastern Highlands and the sub-Saharan Africa. In some areas where temperatures have lowered, cases of malaria have decreased but unfortunately in Africa malaria is still a threat to human health. Cases of communicable diseases have also been recorded after experiencing climate change related weather events such as a cyclones and droughts. The destruction of water and sanitation infrastructure and water shortages respectively leading to poor sanitation contribute to the rise and spread of diseases such as cholera and typhoid.
Climate change is also accelerating sea level rise as a result of oceans warming and expanding, and glacial melting. This change in the aquatic environment results in saltwater intrusion into fresh water increasing salinity of groundwater basins and well water, as sea levels rise. The rise in salt levels in fresh water systems reduces crop yields and the availability of safe drinking water. It also increases the risk of hypertension, as well as vector borne and diarrheal disease.
Indigenous communities that practice subsistence farming and fishing are particularly vulnerable to the impacts of sea level rise on freshwater ecosystems. Low-income communities face greater challenges from food security as saline intrusion disrupts agriculture and availability of safe, reliable drinking water whilst low-income individuals disproportionately lack disaster insurance and often lack access to resources to recuperate from property loss, placing them at greater risk for destabilization and displacement from floods or submergence related to sea level rise.
Climate change tempers with a number of factors that are key to the survival of human beings. If it continues unabated, chances are the situations will worsen and the survival of humans will be threatened. Mitigation and adaptation measures should be employed to safeguard human life and the future. If climate change continues at this rate; agriculture and business will be threatened, whereas the health sector will be threatened, leading to survival becoming unbearable for people on this planet.
