New Evidence That the Ancient Climate Was Warmer than Today’s

Source:

https://www.scienceunderattack.com/blog/2020/12/28/new-evidence-that-the-ancient-climate-was-warmer-than-todays-68?mc_cid=fb29760038&mc_eid=80ee5bb983

"Two recently published studies confirm that the climate thousands of years ago was as warm or warmer than today’s .

 

... That was an era when CO₂ levels were much lower than now ...

 

One study demonstrates that the period known as the Roman Warming was the warmest in the last 2,000 years. 

https://www.nature.com/articles/s41598-020-67281-2?utm_medium=affiliate&utm_source=commission_junction&utm_campaign=3_nsn6445_deeplink_PID100032693&utm_content=deeplink

 

The other study provides evidence that it was just as warm up to 6,000 years ago. 

https://ui.adsabs.harvard.edu/abs/2018AGUFM.C32B..08B/abstract

 

Both studies reinforce the occurrence of an even warmer period immediately following the end of the last ice age 11,000 years ago, known as the Holocene Thermal Maximum.

 

The first study, undertaken by a group of Italian and Spanish researchers, reconstructed sea surface temperatures in the Mediterranean Sea over the past 5,300 years. 

 

This particular study utilized fossilized amoeba skeletons found in seabed sediments. The ratio of magnesium to calcium in the skeletons is a measure of the seawater temperature at the time the sediment was deposited; a timeline can be established by radiocarbon dating. 

... With the exception of the Aegean data, the results all show distinct warming during the Roman period from 0 CE to 500 CE, when temperatures were about 2 degrees Celsius (3.6 degrees Fahrenheit) higher than the average for Sicily and western Mediterranean regions in later centuries, and much higher than present-day Sicilian temperatures. 

... The second study was conducted by archaeologists in Norway, who discovered a treasure trove of arrows, arrowheads, clothing and other artifacts, unearthed by receding ice in a mountainous region of the country. 

 

Because the artifacts would have been deposited when no ice covered the ground, and are only being exposed now due to global warming, temperatures must have been at least as high as today during the many periods when the artifacts were cast aside.

 

The oldest arrows and artifacts date from around 4100 BCE, the youngest from approximately 1300 CE, at the end of the Medieval Warm Period. 

 

... During the Holocene Thermal Maximum, which occurred from approximately 10,000 to 6,000 years ago ... global temperatures were higher yet. 

 

In upper latitudes, where the most reliable proxies are found, it was an estimated 2-3 degrees Celsius (3.6-5.4 degrees Fahrenheit) warmer than at present. The warmth contributed to the rise of agricultural societies around the globe and the development of human civilization."