Environment

Looking to the past to learn more about a warming planet's possible future

Scientists believe that by peering into the ocean's past they can learn valuable lessons about the possible ramifications of global warming
Scientists believe that by peering into the ocean's past they can learn valuable lessons about the possible ramifications of global warming

Expectations of what a warmer planet might mean range from the inconsequential to the much more dire, but researchers are working to bring more scientific data to the debate. For geologists at Florida State University (FSU), one way to learn more about the future is by visiting the past, 94 million years ago to be exact. By studying a major warming event at that point in the Earth's history, the researchers have found that it caused changes in ocean chemistry that were incompatible with vital nutrients needed to support life.

The end of the Cenomanian period, between 94 and 100 million years ago, was a pretty volatile time for the climate. Big swings in sea levels and temperatures, a lack of polar ice and Canadian palm trees were some of the defining features of a totally different time on this planet. Research from earlier this year has suggested that this major climatic event wiped out the ichthyosaurs, the highly adaptable marine reptiles that ruled the oceans for the 157 million years previous.

Looking to dive further into how these dramatic changes to the ocean's ecology unfolded, the FSU researchers obtained sediment samples from under the seafloor off the coast of Venezuela. They landed themselves a 10-meter (33-ft) slab which they linked to the massive climate turnover event through analysis of microfossils and shell organisms within.

Further examination of the sample revealed that changes in the ocean's nutrients at this time affected certain types of natural elements, or vitamins, causing some of them to die off completely. Two that vanished were vanadium and molybdenum, both of which are important trace metals that play a role in nitrogen fixation, a process that converts atmospheric nitrogen into ammonia and is essential to all life. Previous research has linked low molybdenum levels in the ocean to stunted evolution of animal life.

"These trace metals were drawn down to levels below where primary producing organisms, the base of the ocean food chain, can survive," says Assistant Professor of Geology at Florida University, Jeremy Owens. "This change inhibited biology."

The researchers also say that the absence of these trace metals is indicative of oxygen deficiency in the ocean water around the world, creating dead zones where it is difficult for life to exist.

Granted this all happened a very long time ago, but the scientists believe that by peering into the past of the world's oceans they can learn valuable lessons about the possible ramifications of global warming, a trend that has seen Earth sweat through 13 consecutive months of record temperatures.

"This is the best window to understanding future climate change," Owens says. "It gives us insight into the cascade of events that can affect the entire ocean."

The research was published in the journal Earth and Planetary Science Letters.

Source: Florida State University

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10 comments
Lawnmowerman
The dessert pictured is characteristic of an ice age. In this case, the Earth has a high visible and mid IR albedo. More radiation is returned to space.
Robert in Vancouver
So there was global warming 100 million years ago! The science is settled, it was caused by CO2 generated by humans and Canada's oil sands.
toddzrx
Great: more government-funded climate change "science" to tell us it's all going off the rails. Can't wait until this silliness is over.
Pioj
To those who choose not to understand the issue but still like to comment on it, under the delusion that they have something to contribute, the simple point is that, logically, the fact that the earth has warmed in the past under a certain set of conditions doesn't preclude it from warming now under different conditions which have been human induced (ie., increasing CO2 by 40%). According to denier logic, if I put my hose inside my water tank, turn it on and the tank overflows, it can't have anything to do with the water coming out the hose. After all, the tank had overflowed in the past, when it never had a hose in it. Conveniently overlooking the fact that it was after a raingstorm.
ljaques
"We're not having any luck at all predicting future or current climate change with anything even remotely resembling accuracy, so let's start looking 94 million years ago, where we have so much more data to rely on. Yeah, that's the ticket!"
woz
Pioj - wake me when the alarmist projections start even remotely matching the real world. Projections are not observations. The scientific method has been corrupted today to the extent that science itself has lost most of its credibility.
Pioj
woz _ Parroting denier crap without substantiation doesn't contribute anything. Models are useful tools but they're not what the science is based on; if you had a clue, you'd know that. Climate science is based on many scientific disciplines, including Paleontology, geology, atmospheric physics etc. All very well established and understood. Anyway, if you were woken up, would the quality of your posts be improved? I doubt it.
vernwrites@gmail.com
Pioj, I do appreciate hearing from a KoolAid drinker. As an old field/systems engineer who had to use real science to fix things rather than dingbat ideas that were 'peer reviewed' by fellow 'true believers', I was forced to trust pragmatics... If it works it's true. If you have to fudge numbers and go back 94 million years, enjoy your fantasy. All that said, I'd like to know if the paleontologists or others of that ilk have dug up a 94 million year old SUV yet? Please send a pic...
andromalius
vernwrites@gmail.com "I'd like to know if the paleontologists or others of that ilk have dug up a 94 million year old SUV" First you need to learn how the earth works. The suv you are looking for has been around for longer than 94 million years and they have something to do with how tectonic plates move or the things that cause earth quakes, volcanoes "the suv from 94m" the earth was more active millions of years ago. Carbon is stored in the earth volcanoes spew out the co2 one carbon atom and two oxygen atoms thus the burnt form of pure carbon and over billions of years we had these co2 sucking plants called plants tear apart the co2 into oxygen with the suns energy and use the carbon as energy storage va sugar the plants die and over millions of years are turned into coal due to time and pressure. Over this time animal adapt to the environment that has been cooling "iceage" due to the carbon that plant have stored as coal we evolved during the last ice age thus we are fit for the cold just as all the plants and animal are that evolved along with us during the last ice age. we humans on the other hand are putting the stored dead plants energy sugar aka coal back into the environment to heat it back up to the temps way before the ice age "a time before we existed and very different plants and animals lived" thus harming the life that evolved in the past ice age and the ecosystems and food chains that go along with them. We are messing with a huge system. plant and animal life does not move or adapt as quick as humans are putting co2 back to its prehistoric numbers. We will kill the animals we eat and the plants we eat and flood a good percent of our land with sea water due to ice melting at the poles. narcissistic ego will not save the future generations from food and water shortages while other animals goes extinct. this is a great extinction caused by a variable in a global ecosystem we messed with for electrical energy and transportation. its like your blood. it has a pH level and if it goes over that certain pH you go into a coma from acidosis and die also known as dying from a lack of oxygen. our environment is a lot like that but replace pH with temp.
Bob Ehresman
Pioj:
I undestand it better than you. The factors causing climate change are natural and have been present through out history. The correlation between CO2 and the feeble warming we are currently experiencing is much weaker than the correlation with solar flux. Indeed, the next 25 years or so will cool off CO2 not withstanding. Because the sun is going into a period of dormancy similar to if not as long or deep than the Maunder Minimum which exacerbated the "little ice age" of the 17th century.
This article is laughable because you dont have to go back millions of years to find warmer times. The year the Magna Carta was signed was far warmer than now. And warmer periods yet have been experienced during the Anthropocene period. Before we discovered fire, much less interesting things to burn like petroleum or coal.
Go look at the ice core record and find out the truth.