The Future of Earth’s Mammals
- Computer modeling predicts that almost all land mammals on Earth will die out in 250 million years.
- If a species similar to humans still exists at that time, technology may be their only hope for survival.
- This extinction is not related to current human-driven climate change, but rather a result of long-term trends.
The Two Long-Term Trends
- The sun is gradually getting hotter, leading to a 2.5% increase in heat reaching Earth’s surface in 250 million years.
- All continents are expected to merge into a supercontinent named Pangaea Ultima, resulting in extreme temperatures.
The Impact on CO2 Levels
- As a consequence of these trends, carbon dioxide levels are likely to rise.
- In the dry interior of Pangaea Ultima, less CO2 will react with rocks, exacerbating the problem.
The Bleak Future for Mammals
- Researchers used a geochemical model and climate model to determine the future conditions on Pangaea Ultima.
- In almost all scenarios, mammals would face conditions beyond their upper limits of survivability.
- Even if some mammals managed to survive, life would be extremely difficult due to the extreme weather.
The Advantage of Birds
- Birds have a better chance of survival, as they can tolerate higher temperatures and migrate long distances.
- This resilience is attributed to their dinosaur lineage.
Possible Return of Reptiles and Dinosaurs
- With the extreme heat, reptiles and possibly dinosaurs could make a comeback as dominant species.
Expert Opinions
- Scientists find the modeling and results of the study reasonable and plausible.
- While some mammals might adapt, the overall impact would be detrimental.
The Long-Term Fate of Earth
- Even beyond the break-up of Pangaea Ultima, Earth will face further challenges.
- The sun’s increasing output will eventually lead to the loss of oxygen from the atmosphere.
- Ultimately, the sun will turn into a red giant and Earth will be destroyed.
- However, the possibility of other planets and the ultimate fate of the universe remains uncertain.
