The fact that we're today so far out of bounds of what we might consider normal is cause for alarm and should be surprising to everybody. — Matthew Osman, a geosciences postdoctoral researcher at UArizona
The fact that we're today so far out of bounds of what we might consider normal is cause for alarm and should be surprising to everybody. — Matthew Osman, a geosciences postdoctoral researcher at UArizona
Global temperatures over last 24,000 years show today's warming 'unprecedented'
An effort to reconstruct Earth's climate since the last ice age, about 24,000 years ago, highlights the main drivers of climate change and how far out of bounds human activity has pushed the climate system.
  • It verified that the main drivers of climate change since the last ice age are rising greenhouse gas concentrations and the retreat of the ice sheets.
  • It suggests a general warming trend over the last 10,000 years, settling a decade-long debate about whether this period trended warmer or cooler in the paleoclimatology community.
  • The magnitude and rate warming over the last 150 years far surpasses the magnitude and rate of changes over the last 24,000 years.
"This reconstruction suggests that current temperatures are unprecedented in 24,000 years, and also suggests that the speed of human-caused global warming is faster than anything we've seen in that same time," said Jessica Tierney, a UArizona geosciences associate professor and co-author of the study.

Tierney, who heads the lab in which this research was conducted, is also known for her contributions to the Intergovernmental Panel on Climate Change reports and climate briefings for the U.S. Congress.

"The fact that we're today so far out of bounds of what we might consider normal is cause for alarm and should be surprising to everybody," said lead study author Matthew Osman, a geosciences postdoctoral researcher at UArizona.


An online search of "global temperature change since the last ice age" would produce a graph of global temperature change over time that was created eight years ago.

"Our team's reconstruction improves on that curve by adding a spatial dimension," Tierney said.
Read the full article: https://www.sciencedaily.com/releases/2021/11/211110131616.htm