New research reveals that over the past 500 million years, Earth’s average surface temperature has fluctuated more dramatically than previously understood, reaching historic highs.
The average global surface temperature during this extensive period has been estimated at 24°C (75°F), with extreme peaks hitting 36°C (97°F) and dipping down to 11°C (52°F), based on the latest comprehensive study.
“Our findings indicate that greenhouse intervals, characterized by high carbon dioxide levels, can lead to temperatures exceeding earlier projections,” states a researcher from a prominent natural history museum.
During the warmest phases, average surface temperatures in tropical regions soared to 42°C (108°F), rendering some land areas inhospitable for flora and fauna. Notably, even polar regions experienced significant warming, with temperatures surpassing 20°C (68°F).
“It’s likely that certain regions experienced uninhabitable conditions or drastic reductions in biodiversity during these extremes,” the researcher adds.
The study also uncovers a robust correlation between atmospheric carbon dioxide levels and global temperature that surpasses prior expectations. Given the expansive timespan, researchers initially anticipated a weaker link due to other influencing factors.
“This was quite unexpected,” the researcher explains. “It suggests that atmospheric carbon dioxide concentrations are even more critical in regulating Earth’s climate than we had thought.”
Scientists have long acknowledged that for most of the Phanerozoic Eon, Earth’s climate was significantly warmer than today, lacking large ice sheets. However, the specific temperatures during this era remained uncertain.
To address this, the research team utilized a combination of fossilized oxygen isotope analysis and climate models, running hundreds of simulations to accurately estimate average global temperatures at various intervals.
Due to the complexity of these simulations, they examined periods of a few thousand years every 5 million years, according to a member of the research team. “These snapshots of climate history are invaluable,” he notes.
This innovative methodology, known as data assimilation, merges observational data and modeling techniques. While frequently applied in weather forecasting, it has not been systematically used for climate analysis over the past 500 million years until now.
This groundbreaking research is seen as a significant advancement in understanding Earth’s temperature history. However, experts caution that results are not definitive, as they rely on certain assumptions regarding data accuracy and model reliability.
“There is still much to uncover about the Phanerozoic climate,” another expert remarks. “Enhancing our temperature estimates during this period and earlier epochs is crucial for understanding the relationship between life and environmental changes.”
Significantly higher past temperatures underscore the urgency of addressing contemporary human-induced climate change. The rate of current warming is alarming and poses serious challenges.
“Humans have adapted to cooler climates and typically thrive near water sources, close to sea level,” the researcher warns. “We now face critical issues including diminishing water resources, escalating storm severity, rising sea levels, and a decrease in livable and arable land.”
