Translations:AY Honors/Biodiversity/Answer Key/50/en

• Habitat Destruction: Damaging human activity continues to encroach on natural environments, thereby destroying the habitats of countless species. As our numbers rise, cities, infrastructure and cropland are growing and merging into each other, fragmenting the remaining habitat and leaving isolated “islands” of natural populations of plants and animals too small to survive. According to IPBES, only one quarter of land areas and one third of oceans remain relatively undamaged by human activity.
• Overexploitation: Humankind’s relentless consumption of resources such as timber, oil and minerals is continuing to destroy natural habitats around the globe. We are also putting enormous pressure on populations of wild species, both by bushmeat hunting in the developing world and by large-scale industrial fishing in our seas. Wildlife poaching and trafficking still present a huge threat to many species, including rhinos, tigers and pangolins.
• Climate Change: Our planet is on the verge of a climate crisis due to our endless production of greenhouse gases including carbon dioxide and methane. We are headed for a 3-4 °C warmer world by the end of the century if nations' current climate ambitions are delivered on. We are already seeing species decline due to global temperature increase. Every half a degree of warming has a huge knock-on effect on ecosystems, with mobile species running out of areas to migrate to and temperature-sensitive organisms like corals undergoing massive die-offs. When keystone species like reef-building corals disappear, the rich and complex ecosystems they support collapse as well.
• Pollution: As populations increase, the disposal of waste from households, agriculture and industry, becomes an increasingly serious issue. Our oceans are becoming choked with plastic waste which is killing millions of animals, from sea turtles to whales. The Ellen MacArthur Foundation estimates that by 2050, there will be more plastic than fish in the sea. As well as affecting the lives of humans, noise, light and chemical pollution all damage the health of wild species.
• Agricultural Intensification: Agriculture deserves a special mention here as it is a primary driver of habitat destruction, climate change and pollution. Agriculture takes up 50% of all habitable land on Earth, 80% of extinction threats to mammal and bird species are due to agriculture, and our modern food systems are also the biggest contributor to climate change, responsible for around a third of all greenhouse gas emissions, with more than half of these coming from animal agriculture. In order to meet the unsustainable consumption patterns of the Global North and feed our huge population, humanity has developed agricultural systems which rely on monocultures, artificial fertilizers and pesticides. Monocultures are increasingly susceptible to disease so require widespread pesticide use which destroys insect populations. Intensive farming leads to soil depletion and runoff from farms pollutes water bodies and causes harmful algal blooms and the collapse of fish stocks.
• Invasive Species: Human travel across the world has a very large emissions footprint but it has also allowed the spread of invasive species, both accidental and intentional. As a consequence of the introduction of non-native species to some areas, such as rabbits and cats in Australia, goats on St. Helena, and American mink in Great Britain, we have put many vulnerable ecosystems at risk, threatening native species and diminishing biodiversity.