Carnian Pluvial Episode: The Time Rain Fell on Earth for 2 Million Years

The Carnian pluvial episode also called the Carnian pluvial event, is known as a major interval or dramatic shift in Earth's global climate. However, this period in ancient history is bizarre since it was also the time when intense rainfall lasted not for hours or days, but for 1 million to 2 million years. One might not imagine this extremely prolonged wet weather in today's time, but it happened before and there is evidence of that.

The sudden climate change that took place approximately 230 million years ago, during the Carnian pluvial event of the Triassic period, also coincided with major volcanic eruptions and a series of extinction events. Some of the most significant effects of the climate shift are global warming, ocean acidification, extreme humidity, and increased precipitation. Marine and terrestrial animals were also affected as well.

Carnian Pluvial Episode

In a 2020 study published in the journal Science Advances, an international research team led by China and the United Kingdom explored the environmental and ecological impacts of the Carnian pluvial episode. The research paper highlighted that the degree of biological replacements in marine and terrestrial ecosystems is not fully understood. Due to this knowledge gap, the research team sheds light on the mystery.

By analyzing fossil data, the research team was able to determine a significant reduction in the genera and species of marine life by 33%. In addition, the scientists linked this decline in biodiversity with major radiations and changes in ocean chemistry during the Carnian pluvian event. Meanwhile, this global climate change event did the opposite for terrestrial animals at that time.

Based on their research findings, the team concluded there were major biodiversity and origination events among land-dwelling creatures such as dinosaurs, crocodiles, lizards, turtles, mammals, insects, and conifers. This means that the climatic and weather impacts of the event decreased evolution in marine environments, but increased it in terrestrial ecosystems.

Could It Rain Again for 2 Million Years?

Recent scientific research showed that the Carnian pluvial phenomenon allowed the evolution and diversification not only of animals but also of other taxa, including plants, bacteria, and fungi. While it is unclear if Earth could experience rain for 2 million years again, the inquiry was brought up again in recent years on different social media platforms, including Reddit, and other online forums.

Over the past 50 years, scientists further confirmed evidence that it rained for 2 million years on Earth Carnian pluvial event. This assertion has been pointed out by geologists who discovered mysterious layers of sediments in some ancient rock samples dating back 232 million to 234 million years ago.

This geological evidence suggests that the extremely wet period during the Late Triassic contributed to the diversification of life across the animal kingdom. This biological boom happened despite the preceding series of mass extinction events such as the Ordovician-Silurian extinction 440 million years ago and Permian-Triassic extinction 250 million years ago, according to the American Museum of Natural History.