Final answer:
Species extinction can result from climate change, human activities, and the introduction of exotic species, with climate change posing a major threat by altering habitats, forcing range changes, and disrupting seasonal cycles.
Step-by-step explanation:
The extinction of a species can be caused by a variety of factors, including climate change, catastrophic events, interactions with other species, and human activities such as habitat loss, pollution, overharvesting, and introduction of exotic species.
Anthropogenic climate change, resulting largely from the burning of fossil fuels, is a significant threat, leading to alterations in regional climates, shifts in animal ranges, and impacts on seasonal food resources and breeding times. The introduction of exotic species, often due to increased global mobility and trade, can also cause significant ecosystem disruptions and lead to species extinction, especially in isolated environments like islands and lakes.