Final answer:
The rate of species extinction has dramatically increased already up to 1,000 times the natural background rate due to human actions like habitat destruction, introduction of exotic species, and climate change caused by burning fossil fuels.
Step-by-step explanation:
The rate of species extinction has increased rapidly in the past 100 years primarily due to human activities such as habitat destruction, the introduction of exotic species, over-harvesting of resources, and anthropogenic climate change. Studies estimate that the current rate of extinction is 100 to 1,000 times faster than the natural background rate observed throughout Earth's history. Moreover, it is projected that in the next century, the rate may accelerate to as much as 1,500 times the background rate if current trends continue. This accelerated loss of biodiversity is unprecedented outside of the five major mass extinction events in Earth's history, with the exception that the current crisis is largely driven by human action.