Question

How are humans impacting biodiversity in ecosystems around the world? Provide two examples to support your claim.

Answer 1

Humans are reducing biodiversity worldwide by altering and destroying habitats, changing climate and biogeochemical cycles, introducing invasive species, and directly overexploiting plants and animals. These pressures lower the number of species, shrink populations, reduce genetic diversity, and change how ecosystems function.

Example 1 — Habitat loss from land conversion (tropical deforestation and agriculture): Clearing forests and draining wetlands to make room for farms, roads, and cities removes the homes and resources many species need. When continuous habitat is fragmented into smaller, isolated patches, populations become vulnerable to extinction from inbreeding, edge effects, and local disturbances. Tropical forest conversion is a major driver of species extinctions because these ecosystems hold especially high numbers of endemic species.

Example 2 — Climate change and warming oceans (coral bleaching and reef decline): Rising sea temperatures stress reef-building corals and cause them to expel their symbiotic algae (bleaching). Repeated or prolonged bleaching events lead to coral death, which collapses the complex three-dimensional habitat that supports thousands of fish and invertebrate species. Loss of reefs reduces fisheries, coastal protection, and overall marine biodiversity across tropical oceans.

Together these and other human activities are simplifying ecosystems, reducing resilience, and increasing the risk of further extinctions. Actions such as protecting and restoring habitat, reducing greenhouse gas emissions, controlling invasive species, and sustainable harvesting can slow or reverse some of these trends.