The assumption that the speed of episodes of climate change in Earth's past was slower than we're seeing today is flawed, researchers say.
Scientists from the University of Erlangen-Nuremburg in Germany and the University of Aberdeen in Scotland conducted a study that looks into how the pace of those past episodes has been consistently underestimated.
According to the study, the scarcity of geologic records of past climate change makes it difficult to gauge the rate of the change over short periods of time, but that doesn't mean rapid change has not happened, although it may be invisible to us today. Researchers say it's hidden because while we can study climate change today in precise time scales, ancient climate change has to be viewed through a wide-angle lens.
"Today we can measure the smallest fluctuations in climate whenever they occur," explains climate scientist Kilian Eichenseer from the University of Erlangen-Nuremburg . "Yet when we look at geological history we're lucky if we can determine a change in climate over a period of ten thousand years."
They posit that the greater the time period studied, the slower the apparent rate of climate change appears. However, when measuring changes in temperature from over thousands and ten thousands of years, it becomes difficult to identify many details of changeability when compared to modern records of short term change. The ancient geologic record of long time periods distorts the data.
"More recent climate change can occur over short periods of time, and it is these types of relatively short-term events that cannot be resolved from the geological record," says lead author David Kemp at the School of Geosciences at the University of Aberdeen.
The researchers emphasize that helping fill in our understanding of ancient climate change should not take away from legitimate concerns over present-day climate change. Eichenseer says that their work has no impact on examining rapid climate changes today. Rather, it points out that the ancient geologic record is not a perfect archive of ancient climate change.
"Reliably comparing and contrasting ancient and modern climate change is therefore problematic," he adds.
While today's climate change happens in episodes — slow, then fast, and often with periods of little change interspersed between them — it makes sense to consider that past trends in climate change would have been similar.
The study was published in the journal Nature Communications on Nov. 10.