We along with the species that share the planet with us are adapted to a cooler climate. Rapidly placing us all in a warmer climate could be dangerous.
A new study jointly conducted by the Smithsonian Institution and the University of Arizona offers the most comprehensive view of how the Earth’s surface temperature has changed over the past 485 million years. In an article published on September 19 in the journal Science, a group of researchers recreated a curve of global average surface temperature covering many millions of years.
As one of the researchers noted, “If you study the past few million years, you won’t find anything close to what we expect in 2100 or 2500. You need to go even further back to periods when the Earth was truly warm, as this is the only way for us to better understand how the climate might change in the future.”
The team created the temperature curve using a method called data assimilation. This approach allowed researchers to combine data from the geological record and climate models to create a coherent understanding of ancient climate. Originally, this method was developed for weather forecasting. In this study, the method was used to retrospectively analyze ancient climate.
The team collected over 150,000 published data points from five different geochemical archives for ancient ocean temperatures preserved in fossilized shells and other types of ancient organic matter. They generated more than 850 model simulations of how Earth’s climate might have looked in different periods of the distant past, based on the continents’ positions and the atmosphere’s composition.
Source: Article “485-Million-Year History of Earth’s Surface Temperature” from Science journal, September 19, 2024, DOI: 10.1126/science.adk3705.
The new curve shows that temperature fluctuations over the studied period were more extreme than previously thought. Temperature variations spanned a range from 11 to 36 degrees Celsius. The results show that the current global average temperature of 15 degrees Celsius is cooler than Earth was for most of this period.
Periods of extreme heat were most often associated with increased levels of the greenhouse gas carbon dioxide in the atmosphere. Current greenhouse gas emissions caused by anthropogenic climate change are now warming the planet much faster than even the most rapid warming events of past periods. The rate of warming puts species and ecosystems worldwide at risk and causes a rapid rise in sea levels. Some episodes of rapid climate change in the past triggered mass extinctions.
While this new article is a reliable study of temperature changes to date, it is far from complete. Researchers will continue to uncover additional clues about the distant past, which will help to revise this curve in the future.
Baltabay Syzdykov, independent expert
