Two of the most important and widespread environmental changes will be discussed in detail. The first is the occurrence of deforestation which is globally a problem and desertification also occurring on the majority of continents. Deforestation has an impact on desertification. Various aspects such as the spatial and temporal scale, the causes, and contributors of such manifestation, as well as human impacts and whether all types of global environmental change can be generalised, will be comprehensively considered.
Introduction to Deforestation
An important environmental issue, deforestation, is both a complex global and local problem and Africa, being a developing continent, is being most widely and devastatingly affected by such rapid occurrence. It compromises the notion of sustainable development by impacting the environment in a very immediate and detrimental way. Even though forests play an imperatively environmental vital role, as it supports vital ecosystems and houses a myriad of fauna and flora, it is being destroyed and cleared at an astronomically fast rate without having enough time to restore itself, causing inestimable habitat changes, as well as reducing carbon storage. The United Nations Food and Agriculture Organization (FAO) estimated that, from 1990 to 1995, the annual loss was estimated at 12.7 million hectares Furthermore, deforestation account for roughly one-sixth of total anthropogenic emissions of greenhouse gases and degradation may account for 10% of total emissions in the tropics. Tropical deforestation is responsible for 6–17% of global carbon dioxide emissions that affect climate change (Angelsen & Kaimowitz 1999; Pfaff et. al 2013; Cassea et. al 2004).
Spatial characteristics
It is widely known that deforestation occurs in both developed and developing countries, but at different geographical contexts in specific localities and are characterised by different regional aspects, such as aridity, as well as diverse human-environment conditions. For example, deforestation occurring in Africa will markedly differ from that occurring in Asia because of factors such as poverty and a more arid climate. Each type experiences deforestation at a different rate and extent. Within Brazil, as in most tropical countries, the native forests are being lost through conversion to agriculture”. Brazil and Indonesia have accounted for a large portion of the global deforestation totals. The scale (magnitude) at which it occurs also significantly differs as it can either be on a small or larger scale, depending on what kind of activities (e.g. agricultural and logging) take place. Tropical forests are disappearing as a result of many pressures, both local and regional, acting in various combinations in different geographical locations. Some of the most important places where deforestation is taking place, specifically in developing countries, include Africa, in particular the Congo, in South America, referring to Peru and Brazil, and India, Indonesia, and China as well as developed countries, such as Russia, Canada, the USA, and Australia (Pfaff et. al 2013; Geist and Lambin 2002).
Map 1: Deforestation data on occurrence around the world (Source: The World Bank 2011).
Deforestation, concisely described as the permanent clearing of forests, takes place as a result of myriad activities, most notably include agricultural expansion, such as permanent and shifting cultivation, cattle ranching, and wood extraction for commercial use as well as fuelwood and charcoal production.
Causes and contributors of deforestation
Deforestation occurs at different times at different regions around the world as land use changes, leading to deforestation, varies over time. Forests are depleted over a few years and are used for different activities. As a result of multifaceted socio-economic and geographical problems, especially faced by Africa, deforestation is taking place. Mostly notably the highest contributors to deforestation are small farmers, forest-dependent people, loggers, ranchers, as well as plantation companies.
There are several explanation as why forests are shrinking significantly. However, Cassea et. al (2004) argue that “it is more difficult to establish links between underlying factors and deforestation than between direct or immediate causes and deforestation”. Nonetheless, a clear distinction can be made between direct, proximate causes that directly impact forest cover, that originate from intended land use, pertaining from agriculture activities and expansion, wood collection, infrastructure extension, pasture land as well as indirect, underlying causes underpinning the direct causes which include social processes, referring to migration, human population dynamics, export prices, property rights, and government policies. This clearly indicates that socio-economic considerations impact deforestation considerably. Deforestation is driven by identifiable regional patterns of causal factor synergies, referring to economic factors, institutions, national policies, and remote influences driving agricultural expansion, wood extraction, and infrastructure extension (Cassea et. al 2004; Geist and Lambin 2002; Pfaff et. al 2013; Angelsen & Kaimowitz 1999).
There is one primary and direct factor which contributes the most to deforestation and land-use changes, namely, agricultural expansion. It includes forest conversion for permanent cropping, cattle ranching, shifting cultivation, and colonization agriculture. In permanent cultivation, the expansion of food-crop cultivation for subsistence is three times more frequently reported than the expansion of commercial farming (less than 25% for all regions). This is particular true for developing countries. Land is frequently converted to pasture or crops when forest is cleared. At the underlying, indirect level, deforestation can be attributed to driving factors that act synergistically and being driven by the interplay of economic, institutional, technological, cultural, and demographic variables.
Economic rationality
It is no surprise that economic factors, too, lead to deforestation as commercialization and the growth of timber markets and market failures drive deforestation. Such economic variables can include low domestic costs (for land, labour, fuel, or timber), product price increases (mostly for cash crops) and the requirement to generate foreign exchange earnings also has an impact. By clearing forests it is possible to create agricultural land, higher prices for agricultural products, produce staple food, commodities (e.g. biofuel), and even profiting from timber sales. Thus, there are socio-economic incentive to exploit forests in this way. As frontier agriculture becomes more profitable, both the existing population and migrants from other areas begin to shift resources into forest clearing. Development also impact the rate at which deforestation occur. Ecosystem services don’t generate revenue, thus aren’t part of many countries’ decision-making processes (Angelsen & Kaimowitz 1999; Geist and Lambin 2002).
Institutional factors
These relates to formal pro-deforestation measure including land use policies and economic development of colonisation, transportation (for agriculture and logging and fuelwood collection), and policy failures (e.g. corruption).
Technological factors
These include agro-technological change, with agricultural intensification having no distinct impact separate from agricultural expansion, and poor technological applications in the wood sector (leading to wasteful logging practices). Technology has both a direct effect on farmers’ behaviour and an indirect effect resulting from its impact on product and factor prices (including wages)(Geist and Lambin 2002; Angelsen & Kaimowitz 1999).
Cultural or socio-political factors
These include variables such as economic and policy forces and attitudes of the public.
Demographic factors
In-migration and population pressures also lead contribute to it. An increase in population density is also stressful on forests as this land is used for construction, fuel, and agriculture.
Other discernible causes can also be included, such as land use and clearing for housing and as a result of urbanisation, wildfires and overgrazing can unintentionally lead to the clearing of forests, fire charcoal and palm oil production (especially in Indonesia and Malaysia and in some parts of Africa), and mining are also a contributor, farmers clear forests to plant and cultivate staple crops or to let livestock graze on land. When land productivity declines, the land is furthered exploited for cattle grazing. People, especially poor people, who live close to forests are dependent on it to sustain themselves, as their subsistence depends on the source of forests as it provides critical fuelwood and food sources. Therefore, their livelihoods depends on an unlimited forest resource.
Human influences on phenomena
It is indisputable and inevitable that anthropogenic activities can, and have, caused deforestation to take place at an accelerated rate. In fact, humans are the primary cause of such clearing of forests. Many people, especially in the poorer, more developing parts of the world, forests are a source for survival and subsistence and rely totally on it and therefore are forest-dependent people. Farmers, loggers and ranchers modify the land to suit their needs, and forging and collecting wood from the land, thereby altering the quality of the forest.
Introduction to Desertification
Desertification is principally a man-made phenomenon and a widespread and irretrievable type of land degradation which occurs primarily in dryland environments. Desertification is linked to global environmental change through climate, biodiversity loss, human dimensions, and land change”. Over the last couple of years, desertification has rapidly occurred which has led to the considerable loss of arable land, leading to marginalisation. Desertification is the spread of desert-like conditions in arid and semi-arid conditions. It is a result of pressure from both climatic and human factors (Laki 1994; Middleton 2008; Phillips 1993). Phillips (1993) further elaborates, stating that “it may be the result of inherent biophysical feedbacks in dryland systems”. The UN Convention to Combat Desertification (as cited in Middleton 2008) defines desertification as “land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities. At least 35% of the earth’s land surface is threatened, inhabited by 20 % of the world’s population.” Many earth surface systems are unstable, and thus such aspects would inevitably lead to permanent decline. Natural vegetation clearing has taken place at a considerably fast rate, especially over the last couple of years which leads to desertification.
Spatial characteristics
Desertification specifically occurs in drylands, including arid, semi-arid, and dry subhumid zones. For example, in the Sahel, high pressure air-mass movement is thought to have contributed to desertification (Laki 1994). Food security inexorably affect desertification. Phillips (1993) notes that “this degradation occurs on all continents (except Antarctica)” indicating just how extensive and its reach truly are and that it takes place in spite of geology and temperature variances.
Map 2: Global Desertification Vulnerability - Source: United States Department of Agriculture 2003.
Causes and contributors of desertification
Land that are extensively used, contribute to desertification and as Middleton (2008) note, “they can be classified in intensive grazing, wood cutting, livestock overpopulation, over cultivation, overexploitation of vegetation, and a high demand for water resources”. These worries then lead to an inherent instability in vulnerable areas. These all have an exponential and long-term impact on the environment. Salinization of irrigated cropland is also responsible. Laki (1994) notes that the main factors contributing to desertification include “drought, population growth, the spread of extensive agriculture, deforestation, rapid urbanization, the erosion of local political power, the lack of economic institutions and the absence of social institutions which have tended to reduce the capacity of the local people to cope with the resource degradation problem”. Thus, like in the case of deforestation, it is widely influenced by human-induced activities, but also because of climatic factors such as climate change. It also, in turn, causes weather fluctuations especially drought. This have an enormous detrimental impact on valuable ecosystems. As such, desertification is a serious ecological problem and as Laki (1994) argues “the rate at which the process has been occurring has been estimated at 5-10 km per year”. Furthermore, erosion will take place as there is no vegetation cover. Land-ownership patterns also lead to desertification.
An enormous human population growth has occurred in the areas that are facing desertification, coupled with the inevitable need for natural resources, but the land can’t sustain all of these demands. Drought, naturally occurring or exacerbated by the human stresses and exploitation of land resources, have also resulted in greater occurrences of desertification. Different physical factors of soil are influenced by desertification, including depth, organic matter and the fertility of soil.
Desertification can thus be divided in three broad causes: continuing climatic changes; short-term weather oscillations; and human factors. In these regions, the ecological balance between climatic conditions, soil, vegetation cover, animal life and soil biota is so precarious that any incidental vicissitude may upset it’. The damage may be irreversible with severe and continued misuse (Laki 1994). Phillips (1993) argues that “the two-way relationships between seven key components in desertification (vegetation, albedo, temperature, precipitation, soil moisture, wind erosion, and water erosion) result in inherent instability”.
Arid areas are exceedingly influenced by climate. The climate of these arid lands is characterized by highly variable rainfall, high temperatures, strong winds and high evapotranspiration rates that exceed annual average (Laki 1994). Desertification leads to significant changes in microclimates. A reduction in rainfall, also unavoidably causes desertification. Soil worsening can be ascribe to human settlements but also their animals. Sand encroachment also lead to a decline in vegetation. Resource abuse (over cultivation, overgrazing, and woodcutting) is primarily responsible for desertification. Agricultural activities are exposing the soils to water and wind erosion.
As Laki (1994) explains, “marginal areas are brought into cultivation during periods of high rainfall. When dry years follow wet, the ploughed loose soil is susceptible to wind erosion, where the clays and silts are carried away as dust and the sand drifts to form dunes”. Deforestation contributes to desertification by making the microclimate more arid. Burning of grasslands is also a major contributor to desertification. Laki (1994) notes that “fire destroys forage and induces changes in the botanical composition of the predominant vegetation formations and communities”. The impact of desertification is also widespread which include hunger and thirst, as crop and animal production deteriorates. Which in turn leads to poverty and a loss of home, and can lead to a loss of life too.
Human influences on phenomena
Even though desertification can be triggered by climate variability (e.g. drought), it is irrefutable that form the above-mentioned statistics and data, desertification inevitably and inextricably are influenced by anthropogenic activities. Numerous examples such as overgrazing, intensive grazing, wood cutting, overpopulation, over cultivation, overexploitation of vegetation, and a high demand for water resources all occur as result of medication or altering the land for human’s needs. One thing is sure, desertification is highly unpredictable and is certainly exacerbated by human-induced land activities.
Conclusion
For deforestation it would be wrong to assume that it will and have the same causes and contributors. Many parts are primarily concerned with technological and economic advancement (thus capital-driven) and in other parts, like Africa who is a developing world, many people solely rely on forests for their fuelwood and food. Thus different causes will result from this. Different localities experience different causes, for example, in Africa it is more arid and poverty will also occur more frequently. The rate and extent of the occurrence of deforestation will also vary tremendously among differ parts of the world.
Both deforestation and desertification are two of the most important (and detrimental) environmental changes facing the world today. The poorer communities which live close to forests and deserts are the most vulnerable to such changes. It is clear that desertification can both be influenced by biophysical and socio-economic factors. It is intensified and exacerbated by human-induced land activities that are taking at an unsustainably rate place.
References
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Pfaff, A., Amacher, GS., Sills., EO., Coren, MJ., Streck, C., & Lawlor, K. 2013. Deforestation and Forest Degradation: Concerns, Causes, Policies, and Their Impacts. Encyclopedia of Energy, Natural Resource and Environmental Economics.
Phillips, J.D. 1993. Biophysical Feedbacks and the Risks of Desertification, Annals of the Association of American Geographers, 83:4, 630-640.
Reynolds, J.F., D. Mark Stafford-Smith, D.M., & Lambin, E. 2003. Do Humans Cause Deserts? An Old Problem Through The Lens Of A New Framework: The Dahlem. Proceedings of the VIIth International Rangelands Congress August 2003, Durban.
United States Department of Agriculture. 2003. Natural Resources Conservation Service: Soils- Global Desertification Vulnerability.
