Biodiversity and Environment (and Livelihood) Security

By Pascal O. Girot as a contribution to UNEP’s Global Environmental Outlook 2008 (GEO4)

8.1 Introduction to the section

Biodiversity provides a plethora of goods and services which sustains livelihoods of millions of rural poor. As global climate change and pervasive changes in the world’s biosphere take place at an accelerated pace, the range and quality of goods and services provided by ecosystems are bound to dwindle. Combined with rapid habitat transformation, climate change will exacerbate the loss of biodiversity and the risk of species extinction. Similarly, healthy ecosystems are also increasing recognized as crucial buffers against extreme climate events, as carbon sinks and as filters for waterborne and airborne pollutants. Thus, a healthy environment is not only an end in itself, but also a means to attain greater human security (Blaikie, P. et al 1994).

Over 10 years ago, in its Human Development Report of 1994, UNDP defined the concept of Human Security, which aims “to safeguard the vital core of all human lives from critical pervasive threats, in a way that is consistent with long-term human fulfilment” (UNDP-HDR 1994). Among these critical pervasive threats are sudden changes in environmental conditions that can be the results of violent perturbations due to the impact of natural hazards, epidemics, economic crises or the threat of political violence and social strife. It can also be the result of slow onset hazards such as drought and shifts in environmental conditions which jeopardize livelihoods and life-support systems for human societies (water and food supply). Again, the brunt of these impacts most often weathered by the poorest and most vulnerable countries of the world. There are shared global risks, with shared but differentiated responsibilities.

Scale shifts become a crucial aspect of any analysis on global environmental change. There is a need to distinguish truly global phenomena occurring at a planetary scale, such as shifts in the Earth’s radiation balance and a relatively rapid decline of stratospheric ozone. Other processes occur as pervasive and world-wide phenomena, but at a regional, national and local scale, such as nitrification of water bodies, coral bleaching, deforestation and loss of biodiversity. In arid or semi arid regions, more erratic rainfall and reduced water availability are predicted by most climate change models. In other regions such as Europe and Central America, increase risk of drought co-exists with increased frequency and magnitude of floods. Changes in mean temperatures will also favor opportunistic species and increase the latitudinal and altitudinal spread of vector-borne diseases such as malaria and dengue

Another key aspect of the relation between human security and biodiversity lies in the unexpected. As C.S.Holling (1986, 1998) suggests, we must brace for surprises, as most natural resource management systems function as multi-equilibrium and non-linear entities. Managed ecosystems are also marked by discontinuous behavior in both time and space, and as such are prone to perturbations and sudden changes. These threshold factors are critically important to understand as ecosystems, under stress due to temperature and rainfall changes and to the impacts of nutrient loading and invasive species, can react suddenly and collapse. This is the creative destruction of ecosystems referred to in recent works by Berkes (1998), Holling (2001) and Gunderson (2004).

Ecosystems do not disappear, but rather they are transformed. Historically, there have been recorded shifts from forest to savannah ecosystems, due to anthropogenic use of fire (Moran, E. 1981). As an ecosystem shifts in structure or function as a result of nutrient loading, invasive species or recurrent hazard such bushfires, the resulting ecosystem –though stable and more resilient- is usually less productive and less diverse, and thus offers a diminished carrying capacity. Ecosystems can irreversibly flip into different form and function, as when a coral reef ecosystem shifts from a coral-dominated to an algal-dominated coastal ecosystem. Such phase shifts in coastal ecosystems have been documented in Jamaica and Belize and in the Indo-Pacific Coral Reefs (Millenium Ecosystem Assessment, 2005:22).

Faced with a myriad of uncertainties, many rural communities have developed coping strategies in order to mitigate these climate risks and multiply options. In drought prone regions of Africa, for instance, many communities have developed traditional knowledge of alternative sources of livelihoods, when crops fail due to lack of rainfall. When agriculture and livestock rearing is no longer option, access to ecosystem goods and services such as non-timber forest products, bushmeat and wild root crops become a critical coping strategy. Even when agriculture is not under threat, bushmeat is often a complementary source of animal protein for many rural communities in Africa and Latin America. These alternative sources of livelihoods are imbedded in traditional knowledge of biodiversity, as refered to in the next section on Cultural Value (see section 9).

How then, do we distinguish what is predictable (yet uncertain) from that which is emergent, incremental and inherently unpredictable? Many of these surprises will bring benefits and opportunities to some, and will spell disaster and chaos for others. All sum up as direct impacts on the most vulnerable segments of the population, the poor and those who relay most heavily on natural resources for their livelihoods. The ultimate insecurity is found in the unraveling of the web of life represented by the world’s ecosystems.

Building on the GEO3 report, which featured sections on Disasters and Human Vulnerability to Environmental Change, this section will highlight the role that biodiversity has played in providing security for people. It will be most focused on the regulating function ecosystems play in buffering climate extremes, purifying water, regulating floods by storing excess water and maintaining baseflow during drought. Ecosystem services also include disease and pathogen regulation. In this sense, the chapter has linkages to the “biodiversity and health”, “biodiversity and agriculture” sections and the climate change, land degradation and water resources chapters of the GEO4 report.. It would include analysis of biodiversity loss as a contributing cause of natural disasters and its consequences for human well-being. The section will reflect upon both the impact of biodiversity loss on natural disasters and the security of people. Finally, it points out key options to harness and enhance these regulating functions, by managing or restoring ecosystems to increase human security.

8.2 State and trends

The concept of ecosystem includes the components and processes that comprise the environment and provides a useful framework for discussions related to the environment. Conservation of biodiversity and the delivery of the associated ecosystem goods and services provide the foundation for human wellbeing, providing food, soil nutrients, clean water, disease and climate buffering, building materials, energy, pharmaceuticals, and much else. Loss of habitat through deforestation, loss of soil and over-fishing are contributing to diminished productivity of ecosystems from forest, agricultural and marine environments.

Globally, one of the major drivers of biodiversity loss is habitat loss due to conversion to agricultural and other uses, as well as overexploitation. Lack of regulation also leads to overexploitation and destructive extractive techniques, especially of forest and marine species. While some ecosystem services such as agro-ecosystems have expanded, according to the Millenium Ecosystem Assessment (2005), others are on the wane such as fisheries, timber production, water supply, waste treatment and detoxification, water purification, natural hazard protection, regulation of air quality, regulation of regional and local climate, and regulation of erosion. These changes are driven essentially by direct causes such as habitat conversion into agriculture or other productive assets and settlements, but also by overexploitation, particularly from over-fishing, introduction of invasive species as well as the long terms impacts of pollution through nutrient loading (nitrogen and phosphorous) in aquatic ecosystems (terrestrial, freshwater and coastal). Other abiotic drivers of environmental change are due to anthropogenic Green House Gas emissions, which are leading to rapid changes in the climate of many regions of the world.

The overexploitation of coastal and marine ecosystems by commercial fisheries constitutes an illustration of the impacts of open-access common pool resources on livelihoods. The collapse of the North Atlantic fisheries is a case in point (quote Bonnie McKay and also chapter by De Sombre and Barkin on the Talbot War in IISD/IUCN’s book on Environment and Security). Many other examples in the GEO3 point to consistent increases in marine catches in most countries of the world over the past decades, a trend which is starting to drop due to collapse in marine populations in both the Atlantic and Pacific Oceans. Increasing pollution and eutrophication of coastal waters are also impacting populations of demersal fish and the livelihoods of traditional fishing communities in many regions of the world. Coral reefs are not immune to this trend in degradation, with increasing impacts on local livelihoods linked to fisheries and tourism.

Current trends in land degradation and loss of habitat continue to contribute to reducing livelihood options while creating the conditions for heightened risks. The interaction between abiotic (climate change, water resources) and biotic factors make for complex, dynamic systems. For instance, there is a clear link between the increased incidence of drought and processes that lead to accelerated land degradation, soil erosion and salinization.Similarly, livestock populations tend to concentrate on available grazing lands during drought, further increasing land degradation. These processes are also exacerbated by structural factors such as land tenure and access to technology, which restrict management options and tend to perpetuate destructive land use practices.

Interactions between climate variability and loss of habitats are also illustrated by the creation of conditions of physical and ecological vulnerability. For example, long spells of drought associated with the El Niño phenomenon (ENSO) contribute to forest fires, as was the case in the Amazon Basin, Indonesia and Central America in 1997-1998. These forest fires also reduced the capacities of natural forests to buffer the impacts of heavy rainfall and hurricanes, as happened during Hurricane Mitch in Central America. These complex interactions and concatenations between climate, ecosystems and local livelihoods need to be better understood.

Climate change and rising mean temperatures over the past decades are also generating rapid changes in the biodiversity and radiation balance of different biomes and ecosystems. With a trend towards the migration of species to higher latitudes and altitudes, certain ecosystems are undergoing more rapid changes than other. In particular arctic and circum-glacial ecosystems are probably those that are most in flux.

With the increase in international communication and travel, the spread of undesirable species has also tended to increase. The introduction of invasive species is another source of increasing pressure on fragile ecosystems such as small islands and inland waterbodies. In freshwater habitats, the introduction of alien species is the second leading cause of extinction. Introduced invasive species can trigger shifts in an ecosystem’s structure and function, producing cascading effects on its productivity and therefore adversely affect those livelihoods that depend on it. Historically, there have been numerous accounts of disastrous outcomes of intentional introductions such as that of the Nile perch (Lates niloticus), which resulted in the extinction of more than 200 other fish species in the Great Lakes in Africa. Another example has been the introduction of the Comb Jelly fish (Mnemiopsis leidyi) in the Black Sea which has caused the collapse of 26 major fisheries and has contributed to the subsequent growth of an oxygen deprived “dead zone” in this inland water body (Millenium Ecosystem Assessment, 2005: 22). Other invasives include aquatic plants such as the Water Hyacinth (EichhorniaCrassipes) a South America native, which has spread to over 50 countries in 5 continents. Its rapid growth has choked inland waterways and deprived other species of oxygen and habitat. This requires constant investment in dredging and clearing of waterway for regional transport. More difficult to control are parasitic or viral infections of wildlife, such as the case of Avian Malaria (Plasmodium relictum) which is decimating Hawai’i’s native bird populations. Unfortunately, potentially damaging introductions continue unabated, in spite of concerted efforts on behalf of many countries. Careless behaviour leads to unintentional introductions. So-called ‘accidents’ now account for the majority of successful invasions.

Since the 1960s, nutrient loading has emerged as one of the most important drivers of ecosystems change in terrestrial, freshwater and coastal ecosystems. The total amount of biologically available nitrogen released by human activities has increase ninefold between 1890 and 1990, and is essentially attributed to the widespread use of fertilizers. Nitrogen and Phosphorous contribute to the eutrophication of freshwater ecosystems and hypoxia in coastal marine ecosystems with the resulting impact on fish species populations and productivity.

Moreover, ecosystem services provide human populations with renewable goods and services that constitute the basis for adaptation to the changing conditions that are sure to characterize the coming decades. Agro-biodiversity continues to be the most reliable source of food security. Nonetheless, dozens of endemic varieties of cultigens are being replaced by commercial seeds or simply lost to future generations. The past is still a source of important lessons on the importance of maintaining food security in the face of a changing environment, as it provides more options for a society to choose from. By understanding the dynamics of poor people’s livelihoods, we can assess how vulnerable or resilient they will be to a changing environment, how they might cope and respond with the resources they have, and how these conditions can be reflected and built upon for successful adaptation strategies.

There is an on-going debate concerning the role of forests in regulating water resources. The useful myth of forests as main regulator of water runoff and groundwater recharge is increasingly being questionned, with evidence from the field (Kaimowitz, 2002).

A recent publication by FAO and CIFOR (2005) reassesses the link between Forest and Floods, suggesting that simplications of the complex interactions between climate, soil conditions and vegetation are misleading. These have led to policies of relocation of populations along flood plains and logging bans, which have wrought far greater impacts on local livelihoods and security, than benefits from flood control. The report demonstrates that forests are in many cases net consumers of water, and that forests have limited effects on limiting large flood events. They do have an impact on reducing local level floods in a small watershed . There are also clear trends in flood damages and loss, which indicate that small scale floods and landslides have a greater cumulative impact at the local level. Clearly not all ecosystems have the potential for providing regulatory services. In particular, some have singled out cloud forests and freshwater wetlands and mangroves as those with the greatest potential for buffering climate extremes.