Nature's Place: Human Population and the Future of Biological Diversity

Robert Engelman, Vice President for Research, Population Action International

Richard Cincotta, Senior Research Associate, Population Action International

Cynthia Gill, Acting Biodiversity Team Leader, Global Bureau Center for Environment, U.S. Agency for International Development (USAID)

Kimberly Sais, Environment Program Financial Analyst, Global Bureau Center for Environment, USAID

May 30, 2000 - What are the direct causes of biodiversity loss on Earth? According to Richard Cincotta, Senior Research Associate at Population Action International (PAI), the five main direct causes of biodiversity loss are habitat loss and fragmentation, biological invasion, pollution, over-harvesting, and human-induced climate change. Cincotta and Robert Engelman presented the findings of their recent PAI report, Nature's Place: Human Population and the Future of Biological Diversity at a recent ECSP meeting. Cynthia Gill and Kimberly Sais of the U.S. Agency for International Development provided comments on the report's policy relevance.

While biodiversity's importance has been recognized for some time, too little work has been done on what a loss of biodiversity will mean for the future. Similarly, what are the exact impacts human population growth and density having on ecologically-sensitive areas? The authors set out to more comprehensively document the direct and underlying causes of biodiversity loss, and specifically, in the twenty-five "hotspots" identified by Conservation International. "Hotspots" are defined by ecologists Norman Myers and Russell Mittermeier as the most threatened species-rich regions on Earth. More than 1.1 billion people currently live in these critical regions with the populations expected to triple in the next twenty years. These areas are especially important because although they cover only roughly twelve percent of the Earth's land surface, they are home to more than twenty percent of the world's human population.

Using geographic information systems (GIS) data from the World Conservation Monitoring Centre and Conservation International (CI), Engelman and Cincotta studied the linked between biodiversity with human population by overlaying satellite imagery. The two main data sources were global population data layers and the boundaries of species-rich threatened areas (primarily from CI).

Cincotta presented the findings of the report, including some basic facts about biodiversity. A simple definition of biodiversity that the author's used in the report was, "the sum total of life's physical expression and genetic potential, embodied in the array of organisms now alive." Biodiversity serves many purposes including providing marketable products (e.g., pharmaceutical drugs, fish stocks), fundamental services (e.g., soil nutrient cycle, pollination); and cultural, aesthetic, and scientific contributions to society. Biologist Thomas Lovejoy has compared Earth's biodiversity to a "library" wherein there lies a wealth of data.

In addition to presenting the five direct causes listed above that cause biodiversity loss, Cincotta also listed the four main underlying causes. These underlying causes include population change, poverty and equity issues, policy failures, and market failures. The role of population growth is particularly problematic as it increases the scale of demand, leads to human-dominated ecosystems, and creates habitat islands. For example, Lake Victoria in sub-Saharan Africa is a species-rich area that has become a habitat island, surrounded by areas of high population density.

What does this population growth mean for policymakers? Three policy challenges result from population growth and density. One, it increases the risks of native species survival, since humans bring in non-native species such as grasses and trees when they change an ecosystem. Two, conservation becomes more difficult and expensive as the number of people in an area increases. For example, nine out of ten threatened species on the U.S. Department of Interior's list, are located in the three identified U.S. hotspots. Third, population growth creates the need for more efficient, more responsive, and greater numbers of institutions (e.g., regulations, policies, programs, and markets). However, an issue that conservationists face in a densely populated area is the issue of property value versus biodiversity. Property values tend to increase as local population grows, making it difficult to purchase adequate land to protect species. California is well-known example in the United States.

Sais and Gill both commented that reports like Nature's Place are extremely useful for policymakers because they elevate the need to conserve threatened biotas while also addressing human population growth and density issues, thereby helping institutions such as USAID to achieve goals of sustainable development. The biggest change in USAID has been the unit of analysis, with a focus on eco-regional conservation, as can be seen in the case study of Madagascar. Gill also outlined the Global Conservation Program, which is working at different scales, experimenting to find the best approach to conservation. One of the main goals of this USAID partnership program is make sure that they broaden the message by targeting all the stakeholders and using participatory methods to ensure sustainable development practices.

Following the presentations, the discussion focused on the need to increase awareness of these NGO publications to congressional staff. While some efforts has already been made among congressional staff, more concerted targeting of the decision-makers will have an impact on conservation in the densely populated regions. Additionally, participants stressed the benefits of increasing private sector investment into biodiversity conservation, to create wider buy-in to the concepts presented in Nature's Place.