Tyler Greathouse and Dr. Gary Bryner, Political Science
There have been numerous international and national attempts to formulate environmental policies that would effectively curb the potentially debilitating decrease in biological diversity; however, many of these policies have failed to meet their goals. The most recent attempt to conserve biodiversity on the international stage was the 2002 agreement at the Convention on Biological Diversity (CBD). Agreeing parties pledged to slow biodiversity loss in their own respective countries by 2010. However, follow up studies showed that the 2010 targets will not be met.
Despite widespread participation, countries return home without any clear plans for the short or long-term. Experts agree that environmental science and policy must be properly integrated to produce substantial results and that there must be a comprehensive understanding of where the Earth’s biological diversity is heading and, more importantly, what mechanisms are influencing the movement. This assessment was conducted to gain a better understanding of the current state of biodiversity and the factors affecting the Earth’s biological resources.
In 2006 Brooks et al published a paper outlining conservation priorities based on the most influential biodiversity studies. My assessment used seven of the nine studies described in Brooks’ paper . The remaining two studies were not used because the frontier forests study was repetitive and the study on megadiversity countries could not be located.
A general evaluation of the seven studies showed that current research is extremely limited due to a lack of comprehensive and long-term data. For example, the United Nations Environmental Programme (UNEP) completed a biodiversity report that stated that only birds and amphibians have adequate information for understanding each group’s extinction risk . Additionally, the differences between the current scientific understanding of terrestrial and marine systems has produced an unbalanced policy approach in past environmental policies. These large gaps in the research make it extremely difficult to adequately integrate the science into sound environmental policy.
However, the following findings provide a starting point. There are currently two million species described with estimates of total species ranging from five to thirty million species. Regarding known vertebrate species, the UNEP biodiversity report states that 30 percent of amphibians, 23 percent of mammals, and 12 percent of birds are threatened . Moreover, researchers have also focused on a macro-scale by classifying the biodiversity trends of discrete geographical regions. The authors concluded that of the terrestrial regions studied 47 percent are critical or endangered while 29 percent are vulnerable and 24 percent are stable or intact . Furthermore, Hoekstra et al found in their assessment of the Earth’s 13 biomes that approximately 22 percent of global land area has been converted to human uses while the most drastic land conversion has occurred in the tropical dry forests of Southeastern Asia where nearly 69 percent of land has been converted. Conversely, nearly 12 percent of terrestrial land area has been converted to protected areas, with close to half of those specifically designated for biodiversity protection . Additionally, in 2008, the International Union for the Conservation of Nature (IUCN) conducted a global bird audit estimated a global total of 9,990 bird species, of which 190 or two percent were considered critically endangered (CE). Of the 190 CE bird species 66 percent have been found to be decreasing with 16 percent having no known population and eight percent possibly extinct. Contrastingly, five percent are stable and five percent of CE species are increasing .
In addition to listing species number and percentage of CE species, the global bird audit provided the top factors contributing to the aforementioned trends. The top four impacts on CE bird species are agriculture and aquaculture, invasive species, logging, and hunting. These four factors affected 65 percent, 52 percent, 43 percent, and 41 percent of CE bird species respectively .
Moreover, Meyers et al presented the responsible factors for biodiversity loss in their ‘Hot Spot’ study. Meyers et al described 25 biologically diverse areas that they considered to have strong potential as conservation areas. All 25 hot spot areas have seen greater than 70 percent reduction in land area due to human impacts and although each hot spot has been affected by multiple human impacts, Meyers et al designated one or two leading causes. Of the original 25 hot spots 32 percent are primarily affected by logging or deforestation activities and 28 percent through agricultural activities. Although these activities are interrelated, Meyers et al does not provide clear cut differentiation on which factor came first, they only specify which factor they have found to be most significant. Furthermore, population growth and resource exploitation each explain 16 percent of hot spot biodiversity loss, while invasive species are the primary cause of only 8 percent .
These cumulative results show that global biodiversity is decreasing at varying rates depending on scope and scale of the study. However, the knowledge that biological diversity is decreasing is secondary to knowing the specific mechanisms responsible for this loss. The purpose of this study was to create a foundation of knowledge surrounding the most significant factors affecting biodiversity. There is a substantial need for further study due to country and region variation. Because there is not a universal or quick fix to the biodiversity problem it is essential that public policy understands what is causing biodiversity loss. In order to educate environmental policy and enable it to conserve the Earth’s biological resources, research must have a stronger focus on the economic and societal factors behind the loss at the global, national, regional, and local scales.
References
- Brooks, T.M. “Global Biodiversity Conservation Priorities.”Science,(2006): 58-61.
- Neville, Ash “UNEP Biodiversity Report.”Chapter 5,(2008): 158-191.
- Ibid
- Olson, D.M. “The Global 200: A Representation Approach to Conserving the Earth’s Most Biologically Valuable Ecoregions.”Conservation Biology, (1998): 502-515.
- Hoekstra, Jonathan “Confonting a biome crisis: global disparities of habitat loss and protection.”Ecology Letters,(2005): 23-29.
- Birdlife International. “Critically Endangered birds: a global audit.”(2008).
- Ibid.
- Myers, Norman “Biodiversity hotspots for conservation priorities”Nature,(2000): 853-858.