What is biodiversity loss and what are its main drivers?

• A. Decrease in species richness and ecosystem function; drivers: habitat destruction, overexploitation, invasive species, pollution, climate change.
• B. Invasive species are the sole drivers of biodiversity loss.
• C. Biodiversity loss is primarily a result of natural evolution and is not a concern.
• D. The main drivers are only climate change.

Answer: (B)

Biodiversity loss happens when the variety of life in a place declines, along with the functions ecosystems provide, such as pollination, nutrient cycling, and resilience to change. This decline is not caused by a single factor but by a mix of human activities that damage habitats and disrupt ecological processes.

The strongest understanding recognizes multiple drivers: habitat destruction and fragmentation reduce living space and isolate populations; overexploitation reduces populations faster than they can recover; invasive species can outcompete, prey on, or bring diseases to native species; pollution degrades habitats and harms organisms directly; and climate change shifts temperatures and rainfall, alters food webs, and increases extreme events. These forces often interact, compounding effects and accelerating losses.

Statements that claim biodiversity loss is driven by only one factor—like invasive species alone, or that it’s mainly due to natural evolution or climate change, or that climate change is the sole driver—miss how interconnected pressures shape ecosystems. A fuller picture shows biodiversity loss as a consequence of several major drivers acting together across different places and times.