Environmental Science

Global Temperatures Over Last 24,000 Years Shows Today’s Warming Is “Unprecedented”

Global Temperatures Over Last 24,000 Years Shows Today’s Warming Is “Unprecedented”

The present global warming induced by human-generated greenhouse gas emissions is the most rapid shift in the planet’s climate since the last Ice Age peaked 24,000 years ago. 

Researchers rebuilt the variance in temperatures over the previous 24 millennia in new data analysis and discovered that present global temperatures are “exceptional.”

The latest research, headed by the University of Arizona and published in Nature, adds to the growing body of evidence that human activity is to blame for the global warming catastrophe. It emphasizes the primary drivers of climate change and the rate at which it is occurring by recreating the Earth’s climate from the last Ice Age.

It found that the global mean temperature increased by around 0.5°C (0.9°F) throughout the 9,000 years between the early Holocene and the start of the Industrial Revolution. 

World could Cross 1.5ºC Warming Danger Threshold within Five Years
Global Temperatures Over Last 24,000 Years Shows Today’s Warming Is “Unprecedented”

However, the global mean temperature has risen by more than 1.2°C (2.16°F) in the previous 150 years. In comparison to natural fluctuation, the size and pace of change are enormous.

“This reconstruction suggests that current temperatures are unprecedented in the last 24,000 years and that the rate of human-caused global warming is faster than anything we’ve seen in that time,” said co-author Professor Jessica Tierney, who is a contributing author to the UN’s IPCC report and briefs the US Congress on climate issues.

“The idea that we’re so far outside the borders of what we may consider normal today should be alarming to everyone,” said lead research author Dr. Matthew Osman. The researchers integrated two distinct methodologies to investigate changes since the last glacial maximum. 

One option is to make use of sea sediments. Mollusk shells can use as a temperature proxy since temperature variations impact the chemistry of their shells over time. This thermometer is not ideal, but it is a nice place to start.

The alternative option is to use simulated climate models based on humanity’s best understanding of Earth’s history climate, which is likewise restricted, but the scientists hoped to reinforce their conclusions by combining the data from both. They developed maps of the whole world, on which temperature variations may traced in 200-year intervals for the past 24,000 years.

“These maps are quite effective,” Osman stated. “Anyone may use them to look at how temperatures have changed around the globe on a very intimate level. Being able to show the 24,000-year development of temperatures in the precise spot where I’m sitting today, or where I grew up, helped me understand exactly how serious climate change is today.” The team is now applying this strategy to prior climate shifts in order to better understands the evolution of the planet’s climate before humanity drastically affected it.