Scientists from the University of Arizona have revealed how cold the last ice age on Earth was. According to the findings of a study published on 26 August in the journal Nature, scientists used data collected from plankton fossils dating back to that period and combined it with climate model simulations using a technique applied in weather forecasting.
The simulation showed that the average global temperature of LGM was 6 degrees Celsius (11 degrees Fahrenheit) cooler than today. For comparison, the average global temperature of the past century was 14 degrees Celsisus (57 degrees Fahrenheit).
"In your own personal experience that might not sound like a big difference, but, in fact, it's a huge change", said Jessica Tierney, associate professor at the University of Arizona Department of Geosciences and lead author of the study.
Tierney and her team created a map to show how temperatures varied across the globe.
"In North America and Europe, the most northern parts were covered in ice and were extremely cold. Even here in Arizona, there was big cooling. But the biggest cooling was in high latitudes, such as the Arctic, where it was about 14 C (25 F) colder than today", said professor Thierney.
According to the study, the average global temperature during the last ice age was about 7.8 degree Celsius (46 degrees Fahrenheit).
Why is this study important? Knowing how cold or warm past climates are is necessary because scientists can predict how our planet will react to climate changes, in particular increases in carbon dioxide levels and the ongoing rise in temperatures. The Earth is currently in the Holocene geological epoch, a transitional period between the greenhouse period and glacier age, with the next ice age estimated to begin in 100,000 years.