Date:

Can fossils help predict when the glaciers will crumble?

Scientists thought an ice sheet formed more than 90 million years ago when the climate was warmer than it is today. Now, fossil evidence suggests that isn’t the case.

This finding could help environmentalists and scientists predict what the earth’s climate will be as carbon dioxide levels continue to rise.

“Currently, carbon dioxide levels are just above 400 parts per million (ppm), up approximately 120 ppm in the last 150 years and rising about 2 ppm each year,” says Ken MacLeod, a professor of geological sciences at the University of Missouri.

- Advertisement -

“In our study, we found that during the Late Cretaceous Period, when carbon dioxide levels were around 1,000 ppm, there were no continental ice sheets on earth. So, if carbon dioxide levels continue to rise, the earth will be ice-free once the climate comes into balance with the higher levels.”

In his study published in the journal Geology, MacLeod analyzed the fossilized shells of 90 million-year-old planktic and benthic foraminifera, single-celled organisms about the size of a grain of salt. Measuring the ratios of different isotopes of oxygen and carbon in the fossils gives scientists information about past temperatures and other environmental conditions.

The fossils, which were found in Tanzania, showed no evidence of cooling or change in local water chemistry that would have been expected if a glacial event had occurred during that time period.

“We know that the carbon dioxide (CO2) levels are rising currently and are at the highest they have been in millions of years. We have records of how conditions have changed as CO2 levels have risen from 280 to 400 ppm, but I believe it also is important to know what could happen when those levels reach 600 to 1000 ppm,” MacLeod says. “At the rate that carbon dioxide levels are rising, we will reach 600 ppm around the end of this century.

“At that level of CO2, will ice sheets on Greenland and Antarctica be stable? If not, how will their melting affect the planet?”

- Advertisement -

Previously, many scientists have thought that doubling CO2 levels would cause earth’s temperature to increase as much as 3 degrees Celsius, or approximately 6 degrees Fahrenheit. However, the temperatures MacLeod believes existed in Tanzania 90 million years ago are more consistent with predictions that a doubling of CO2 levels would cause the earth’s temperature could rise an average of 6 degrees Celsius, or approximately 11 degrees Fahrenheit.

“While studying the past can help us predict the future, other challenges with modern warming still exist,” MacLeod says. “The Late Cretaceous climate was very warm, but the earth adjusted as changes occurred over millions of years. We’re seeing the same size changes, but they are happening over a couple of hundred years, maybe 10,000 times faster. How that affects the equation is a big and difficult question.”

Header Image : In the study, MacLeod examined fossils of organisms that lived 90 million years ago. This photo is an image from a Scanning electron microscope of a planktic (left) and benthic (right) foraminifera from Tanzania. Both shells are less than 0.5 millimeters across.

Contributing Source : University of Missouri

HeritageDaily : Palaeontology News : Palaeontology Magazine

- Advertisement -

Stay Updated: Follow us on iOS, Android, Google News, Facebook, Instagram, Twitter, Threads, TikTok, LinkedIn, and our newsletter

spot_img
Mark Milligan
Mark Milligan
Mark Milligan is a multi-award-winning journalist and the Managing Editor at HeritageDaily. His background is in archaeology and computer science, having written over 8,000 articles across several online publications. Mark is a member of the Association of British Science Writers (ABSW), the World Federation of Science Journalists, and in 2023 was the recipient of the British Citizen Award for Education, the BCA Medal of Honour, and the UK Prime Minister's Points of Light Award.
spot_img
spot_img

Mobile Application

spot_img

Related Articles

Hidden Medieval tower unearthed in Lublin reveals forgotten chapter of city’s past

Archaeologists have uncovered the remains of a previously undocumented medieval tower within the grounds of the former Pobernardine monastery complex, near the Church of the Conversion of Saint Paul on Bernardyńska Street.

Sinkhole reveals lost remains of medieval hospital

A sinkhole that formed outside the York Theatre Royal has led to the discovery of what could be one of England’s largest medieval hospitals.

Chalcolithic cultural treasures unearthed in Caucasus

Archaeologists from the Institute of Archaeology of the Russian Academy of Sciences have uncovered 13 Chalcolithic-era sites, each yielding a wealth of cultural artefacts and material evidence.

Study reveals East Asia’s earliest gold-inlaid spear sheath

In 1954, a bronze spear sheath dating from Japan’s Kofun period (AD 300–538) was found beneath a rock on Okinoshima, a sacred island located off the coast of Munakata, Fukuoka.

Cache of military helmets from both World Wars discovered during roadworks

Road construction works in the Polish city of Wroclaw have unearthed an unusual cache of military objects from WWI and WWII.

Ten Roman wonders of Britain

Discover the Roman Empire’s extraordinary legacy left on Britain through this selection of ten Roman wonders.

New archaeological treasures unearthed at Finziade

Archaeologists excavating at Finziade in southern Italy have unearthed an artisan workshop and a domestic sacellum containing archaeological treasures.

Significant multi-period discoveries in Delbrück-Bentfeld

An archaeological excavation in Delbrück-Bentfeld, a town in the east of North Rhine-Westphalia, Germany, has unearthed nearly 400 features of archaeological interest that span several centuries.