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By Professor Dieter Genske, Department of Environmental Science, ETH-Zurich
In 2004, the Living Planet Report of the Worldwide Fund for Nature (WWF) reported that humans consumed 20% more natural resources than the earth could produce, and that populations of terrestrial, freshwater and marine species fell on average by 40% between 1970 and 2000. In 2004, the average ecological footprint i.e. the amount of land needed to produce the resources required to sustain life and to take up wastes (Wackernagel and Rees 1996) was calculated as 2.2 ha person –1, more than the 1.8 ha of land.
Land is the basis for 90 % of all human food; livestock feed, fibre and fuel (EEA 2006). Land is a basic and finite resource and we are degrading large amounts of it. Oldeman et al. (1991) revealed that of the total land surface (14 894 Mha), 13 % (1964 Mha) is classified as degraded to some extent i.e. an area somewhat larger than the Russian Confederation.
Figure 1.1: Human-induced degradation of soil according to the type (erosion, chemical, physical), degree and cause of degradation (after Oldeman et al. 1990, FAO-AGL 2000)
Human-induced degradation manifests as erosion (84%), with 12% chemical alteration and 4% physical alteration. Of the human-induced degradation, 35% is caused by overgrazing, 30% by deforestation, 28 % by bad farming techniques, 7% by overexploitation of vegetation for domestic use (firewood, timber, etc.) and 1% by industrialisation .
However, the extent of actual degradation may have been underestimated. For instance, the land surrounding a degraded terrain is also affected and thus downgraded. Furthermore, off-site effects such as sedimentation of eroded material need to be taken into account. In order to compensate for these shortcomings, the notion of severity of degradation was introduced ( Bot et al. 2000). This suggests that 90% of the long-settled lands of Europe are degraded to some degree and 58 countries, (21 in Europe) have no un-degraded land left. Fifteen countries have more than 90% of their land severely degraded, another 17 countries have over 75% and a further 41 countries have over 60% of their land severely degraded. Only about one-third of the total land surface shows no signs of degradation, while one-quarter is severely or very severely degraded ( Figure 1.2). It is likely that the economic damage due to land degradation is equivalent to at least 10% of the economic value of global agricultural production.
Figure 1.2: Severely and very severely degraded land as a fraction of total land area (after Bot et al. 2000)
It may be that the costs associated with the remediation of degraded and contaminated industrial wasteland will significantly increase, especially since large terrains of industrial degradation have not yet been assessed. In many European countries, not even half of the existing industrial wasteland has been screened and not even one-fifth has been investigated in detail.
There is a clear correlation between population density and human-induced soil degradation i.e. erosion plus chemical and physical degradation (Figure 1.3). With increasing population the quality of soil decreases and soil functions are lost. However, once land becomes increasingly degraded and eventually sterile and toxic wasteland, it is abandoned and people are forced to move to other regions, accelerating the process of land degradation. The only measure to break this vicious circle is the introduction of sustainable land management techniques.
Figure 1.3: Increase of land degradation with increasing population density (after Bot et al. 2000)
In 1992, the Earth Summit in Rio de Janeiro addressed the problem with its Agenda 21, stating that our practice of consuming resources shall not compromise the ability of future generations to benefit from these resources, a principle that has become known as sustainable development (World Commission on Environment and Development 1987). In Chapter 10 of Agenda 21 the resource land is recognised as a finite resource that shall be managed in a sustainable way. Land degradation should be stopped and measures of prevention and remediation shall be introduced.
Due to the fragmentation of sciences into many disciplines and sub-disciplines, working on land degradation and rehabilitation has become occasionally confusing, sometimes even discouraging. This is regrettable since all scientists involved are actually trying to present measures of land remediation and protection.
A new book by Professor Dieter D. Genske, Investigation, Remediation and Protection of Land Resources, presents information from different scientific fields relevant to this complex problem and harmonises findings and suggests trans-disciplinary solutions for anyone interested in the urgent task of sustainable land management. The book is divided into three major parts namely, natural land; degraded land; and remediating land.
In 1954, Rachel Carson, who published Silent Spring stated:
“The more clearly we can focus our attention on the wonders and realities of the universe about us, the less taste we shall have for destruction”.
With this, she logically extended into our times Immanuel Kant’s notion of:
“...the starry sky above me and the moral law within me”.
That is, the obligation of humans to accept responsibility for the environment in which they live (Kant, 1788). This responsibility shall be based on the moral concept that humans have the capacity to develop—if they dare to take advantage of their own intellect (Kant, 1784).
Professor Genske hopes that his book will contribute to an understanding of the value of resource land, the way that humans degrade it and the options at hand to restore, rehabilitate and protect it.
References
Agenda 21 (1992) UN Department of Economic and Social Affairs, Division for Sustainable Development. www.un.org/esa/sustdev/documents/agenda21/english/agenda21toc.htm
Bot, A.J., Nacht ergaele, F.O. and Young, A. (2000) Land resource potential and constraints at regional and country levels. Food and Agriculture Organisation FAO Rome, World Soil Resources Report 90, 114p.
Carson , R. (1962) Silent spring. Houghton Mifflin (reprinted 2000 in Penguin Classics, 323p)
EEA (2006) www.eea.eu.int. European Environmental Agency Copenhagen
Genske, Dieter D. (2007) Investigation, Remediation and Protection of Land Resources, to be published by Whittles Publishing, Scotland.
Kant, I. (1784) Beantwortung der Frage: Was ist Aufklärung? (Answering the question: what is enlightenment?). Berlinische Monatsschrift 12, 481–494.
Kant, I. (1788, 1993) Critique of practical reason (Kritik der praktischen Vernunft). Prometheus, 193p.
Oldeman, L.R., Hakkeling, R.T.A., Sombroek, W.G. (1991) World map on the status of human-induced soil degradation: an explanatory note. ISRIC Wageningen, 41p
Wackernagel, M. and Rees, W. (1996) Our Ecological Footprint: Reducing Human Impact on the Earth. New Society Publishers, Gabriola Island BC.
World Commission on Environment and Development (1987) Our common future (Brundtland Report). Oxford University Press, Oxford.
WWF (2004) Living planet report 2004. World Wide Fund for Nature WWF, Gland, Switzerland. 42p.