## 13.3 Species Extinction Due to Climate Change This section outlines how climate change acts as a primary driver of species extinction by altering habitats and ecosystems faster than species can adapt. It provides specific examples of species that have gone extinct and those that are currently endangered due to these environmental shifts. ### Mechanism of Extinction Climate change causes species extinction by rapidly altering key environmental factors that organisms depend on for survival. These changes include: - Temperature shifts - Changes in precipitation patterns - Increased frequency of extreme weather events (e.g., storm surges, heatwaves) - Sea-level rise These rapid changes push species beyond their physiological tolerance or adaptive capacity, leading to population decline and ultimately extinction. ## Species Extinct Due to Climate Change Several species are believed to have gone extinct with climate change as a major contributing factor. ### Bramble Cay Melomys (*Melomys rubicola*) - A small rodent native to Bramble Cay, Australia. - Considered the **first mammal to go extinct** due to contemporary climate change. - **Cause:** Its low-lying habitat was destroyed by rising sea levels and storm surges. ### Golden Toad (*Incilius periglenes*) - Lived in Costa Rica's Monteverde Cloud Forest; last seen in 1989. - **Cause:** Climate change led to drought and temperature shifts, making the forest less hospitable. These conditions also likely contributed to the spread of disease (chytrid fungus) that decimated the population. ### Pinta Island Tortoise (*Chelonoidis abingdonii*) - The last individual, Lonesome George, died in 2012. - **Cause:** While human activity was a major factor, climate change disrupted the Galápagos ecosystem, affecting food and water availability. ### Atelopus Frogs (Harlequin Frogs) - Multiple species have gone extinct in recent decades. - **Cause:** The spread of the chytrid fungus, an amphibian pathogen, is exacerbated by climate change. Rising temperatures and altered humidity create favorable conditions for the fungus to thrive in highland areas where these frogs live. ## Species Endangered Due to Climate Change Many more species are threatened with extinction due to the ongoing effects of climate change. | Species | Scientific Name | Primary Climate Change Impact | | :-------------------- | :----------------------- | :------------------------------------------------------------------------ | | **Polar Bear** | *Ursus maritimus* | Loss of Arctic sea ice, which is essential for hunting seals. | | **Adélie Penguin** | *Pygoscelis adeliae* | Reduction of Antarctic sea ice needed for breeding and feeding. | | **Koala** | *Phascolarctos cinereus* | Increased frequency and intensity of heatwaves and bushfires. | | **Snow Leopard** | *Panthera uncia* | Shrinking mountain habitats and prey base due to rising temperatures. | | **Coral Species** | *(e.g., Staghorn Coral)* | Ocean warming and acidification cause widespread coral bleaching. | | **Monarch Butterfly** | *Danaus plexippus* | Disruption of migration patterns and loss of milkweed (primary food). | | **Atlantic Cod** | *Gadus morhua* | Rising ocean temperatures disrupt breeding grounds and food availability. | ## Possible Questions/Answers **Q:** How does climate change contribute to species extinction? **A:** Climate change alters habitats by causing rising temperatures, changing precipitation, sea-level rise, and more frequent extreme weather. These changes can eliminate food sources, destroy breeding grounds, and introduce new diseases, pushing species beyond their ability to adapt and survive. **Q:** Which species is considered the first mammal to go extinct due to modern climate change, and why? **A:** The **Bramble Cay Melomys**. Its extinction was caused by rising sea levels and storm surges that completely inundated its small, low-lying island habitat. **Q:** Explain the link between climate change, chytrid fungus, and the extinction of Atelopus frogs. **A:** Rising temperatures and changes in humidity associated with climate change create ideal conditions for the pathogenic chytrid fungus to spread. This has led to devastating outbreaks in amphibian populations, like the Atelopus frogs, causing mass mortality and extinction.