Biodiversity & Conservation What is identified as the leading global cause of species extinction across ecosystems?

Introduction / Context:
Biodiversity loss is a critical environmental issue. While multiple human activities harm species, one driver consistently emerges as the dominant cause of extinctions: the loss and degradation of natural habitats. This question checks your understanding of conservation biology fundamentals relevant to environmental policy and sustainable development goals.

Given Data / Assumptions:

• The focus is on the primary, overarching cause of species extinction.
• Options list several human activities (agriculture, extraction, development) that contribute to habitat change.
• We are asked for the top cause globally, not a local or sector-specific driver.

Concept / Approach:
Habitat loss and degradation encompass deforestation, wetland drainage, grassland conversion, fragmentation, and pollution-driven quality declines. Although agriculture, extraction, and urban/industrial development are major pressures, they are mechanisms through which habitats are reduced or degraded. Therefore, “habitat loss and degradation” subsumes many individual activities and captures the root, most pervasive driver of extinctions.

Step-by-Step Solution:

Verification / Alternative check:
Global conservation assessments and red lists consistently cite habitat loss/fragmentation as the top threat for terrestrial species, followed by overexploitation, invasive species, pollution, and climate change (trends vary by biome). This corroborates the selection.

Why Other Options Are Wrong:

• Agricultural activities: A major cause but a subset leading to habitat conversion; not broader than “habitat loss and degradation.”
• Extraction (mining, fishing, logging): Important, but again typically operates by degrading/removing habitat.
• Development (settlements, industry): Significant locally, yet part of the umbrella category of habitat loss/degradation.

Common Pitfalls:
Confusing proximate activities (e.g., logging) with the overarching ecological effect (loss/degradation of habitat). Conservation questions often ask for the broadest, root-level category.

Final Answer:
habitat loss and degradation