Threats to Biodiversity: An Overview

Human demands on the world's resources have led to one-third to one-half of the terrestrial planet being substantially altered by human activity. Some ecosystems such as grasslands and freshwater systems are more affected than others, but pollution has modified even the poles and the atmosphere. The major direct threats to biodiversity are covered in this module, including habitat fragmentation, invasive species, pollution, overexploitation, and global climate change. The underlying causes of biodiversity loss, on the other hand, are often more complex and stem from many interrelated factors, the most important of which are overpopulation and overconsumption. In the accompanying exercise, students become aquainted with the IUCN Red List (a critical information resource on the status of wild species) and become familiar with and contrast what factors are most causing species declines locally versus globally.