Threats to Biodiversity

Habitat loss is the single greatest threat to biodiversity. Since 1700, humans have converted approximately 40% of Earth's ice-free land to agriculture and urban areas. Tropical deforestation alone eliminates an estimated 10 million hectares of forest annually—an area the size of South Korea each year. Equally damaging is fragmentation: when a continuous forest is broken into isolated patches by roads, farms, or development, the resulting 'islands' lose species disproportionately. Edge effects—increased wind, light, temperature, and invasive species penetration along fragment boundaries—can render the interior habitat of small patches unsuitable. A 10-hectare forest fragment may lose 50% of its bird species within a decade.