Human Impact on Biodiversity
- Biology
- Ages 14–18 · Grades 9–12
What you’ll find out
- The main human threats to biodiversity are habitat loss, invasive species, pollution, population growth and overharvesting (HIPPO), plus climate change.
- Protected areas, wildlife corridors, reintroductions and regulation can reduce these impacts.
- Solutions are designed, tested against measurable criteria and refined, weighing trade-offs for people and wildlife.
No sign-up and no real names. In the lesson you check your understanding as you read, and practise until it sticks.
Threats to biodiversity
Biodiversity is the variety of life on Earth, and human activities now threaten it more than ever. Scientists sometimes sum up the main threats with the word HIPPO. H stands for habitat loss, the greatest threat, as forests are cleared and wetlands drained for farms and cities. I stands for invasive species, which people carry to new places. On Guam, the brown tree snake arrived by ship and wiped out most native forest birds. P stands for pollution, and the second P for the growing human population. O stands for overharvesting, taking animals faster than they can reproduce. Climate change adds further pressure.
Designing solutions
Human activities can also be redesigned to reduce harm. Protected areas, such as national parks and marine reserves, shelter habitats from development. Where roads or farms divide a habitat, wildlife corridors and overpasses let animals move between fragments. This keeps populations connected and genetically healthy. Reintroducing a lost species can restore a whole ecosystem. After wolves returned to Yellowstone in 1995, elk numbers fell and willows and aspens began to recover along some rivers. Laws also matter. After the United States banned the pesticide DDT in 1972, bald eagle numbers rebounded. Engineers and ecologists test each solution, measure the results and improve the design.
Curriculum links: NGSS HS-LS2-7 · England KS4: Biology · Cambridge IGCSE: Biology · NCERT Biology, Class 12