You can travel back 56 million years to find yourself in a time of intense volcanic activity. This activity caused significant changes in the climate of the planet, making some areas of the far north a tropical paradise.
Although the outpouring carbon dioxide is one reason for warming, there are many other causes. A new study has shown that volcanism caused oceans to mix differently by plugging up the Atlantic and Arctic seaways.
The Paleocene–Eocene Thermal Maximum is an important event in Earth's geological history. However, this remote area of northeast Greenland has not been extensively studied geologically. It lies at a critical point for volcanic activity as well as the flow of water between Arctic and Atlantic.
A team of researchers from the Geological Survey of Denmark and Greenland (GEUS), found that the elevation of the geology of the area caused a degree of fragmentation that cut off two major oceans.
Milo Barham, a paleontologist at Curtin University in Australia, said that "we found that volcanic activity and the resulting elevation of the Greenland continent's edge 56 million years ago caused the formation of a new tropical landscape and narrowing the seaway connecting Atlantic and Arctic oceans."
"So, not only did the volcanic activity spike cause an increase in greenhouse gasses, but also the restriction of water flow between the oceans caused heat distribution problems and acidification in the deeper oceans.
Through a combination of tectonic plates movements and rock made with cooling lava, the uplift would have narrowed Greenland's seaway, which is now much larger than it was before. The deep waters would have transformed into rivers, swamps, and estuaries.
These ocean connections played a significant role in shaping weather and winds around the world, both then as now. This would have meant that the Arctic waters would have been nearly isolated from the Atlantic waters, thereby accelerating the warming already occurring.
However, there was another result: More land meant more migration options to the fauna and flora of the region. Researchers believe that many animals might have used the extra space to relocate to cooler areas.
Jussi Hovikoski, GEUS geologist, says that the volcanic surge also altered the Earth's continental shape, creating land bridges and narrowed straits. This enabled crucial migration responses for mammalian specie such as early primates to survive climate change.
Now, fast forward to today. While there is no moltenlava that extends the continents' sizes, the oceans & the air currents above them are equally important for managing the planet's climate.
Some of the weather patterns we have come to depend on are starting to fail due to the current climate crisis. If they do, it will have severe implications for how the planet cools down or heats up in the future.
Many people have made comparisons between our current situation and the PETM, when there were no palm trees in Arctic. Understanding how climate has changed in the past will help us better plan for the future.
Barham says that recent studies have shown alarming signs of a weakening ocean circulation such as the Gulf Stream. This ocean current is important for global climate. "This slowing could lead to climatic tipping point or irreversible changes in weather systems."
"As floods and fires continue to ravage our planet's ever-warming surface, it seems unlikely that the frozen north of east Greenland could provide insights into a climate world. The geological record provides important insight into the ecological and environmental responses to complex climate disturbances.
Communications Earth & Environment published the research.
