A newly published study conducted by a collaborative team of French and Swiss researchers is suggesting a flaw in the way past ocean temperatures have been estimated. This discovery claims that oceans may have been much cooler over the past 100 million years than records suggest, meaning that the recent spike in ocean temperatures might be more significant and alarming than we thought.
"Oceans cover 70 percent of our planet," explains Anders Meibom, one of the authors of the study from the University of Lausanne. "They play a key role in the earth's climate. Knowing the extent to which their temperatures have varied over geological time is crucial if we are to gain a fuller understanding of how they behave and to predict the consequences of current climate change more accurately."
Over the last few decades, scientists have developed increasingly sophisticated methods to track our ocean's temperature. From a global network of monitoring stations called Argo floats to newer satellite based technology, every day offers a clearer picture of how climate change is warming our oceans.
In order to estimate how ocean temperatures have varied over millions of years, scientists traditionally measure the presence of an oxygen isotope (oxygen-18) found in tiny marine fossils called foraminifera. It was generally thought that the oxygen-18 content found in the calcareous shells was fixed and unchanging over time. These measurements suggested that our global ocean temperature was around 15° Celsius (27° F) warmer 100 million years ago than today.
The new study claims this measurement technique is flawed and shows that the level of oxygen-18 present in foraminifera can in fact change over time. The scientists demonstrated this by exposing the fossils to high temperatures in artificial seawater containing oxygen-18, and through chemical analysis found that it was in fact able to absorb the isotope.
"What appeared to be perfectly preserved fossils are in fact not," says Sylvain Bernard, the study's lead author. "This means that the paleotemperature estimates made up to now are incorrect."
The scientists claim the previous 15-degree temperature shift identified in the fossil record can be explained by a process called re-equilibration. This refers to rises in temperature of up to 30° Celsius (54° F) that occur during sedimentation, causing the foraminifera re-equilibrate with the surrounding water.
"To revisit the ocean's paleotemperatures now, we need to carefully quantify this re-equilibration, which has been overlooked for too long," says Meibom. "For that, we have to work on other types of marine organisms so that we clearly understand what took place in the sediment over geological time."
After running new computer simulations, the team suggest that current paleotemperature estimations have been overstated and ocean temperatures over the past 100 million years may have actually been much more stable. The striking implication of the study is our currently rising ocean temperatures are much more anomalous that previously thought. If global ocean temperatures were in fact relatively stable over the past 100 million years then our current, more accurate measurements are exponentially more disturbing, suggesting a nearly 1 degree rise over the past century.
The new research was published in the journal Nature Communications.
Source: École Polytechnique Fédérale de Lausanne
Are these the same computer simulations that 15 years ago predicted that by now I would be going to Antarctica for beach vacations and the North Pole for fishing?
CO2 and other greenhouse effect gases are increasing, it could take years to slow and stop the increase, more to revert it, all feed-back loops increase and speed-up temperature increases, with all its consequences.
The Paris meeting set a goal not to surpass of 1.5º C above pre-industrial level (PIL) mean, the Marrakech meeting raised the not to trespass limit to 1.7º C above PIL, but in these two years of high Solar energy output, 2016 and 2017, with a peak in Solar cycle, (that came late from expected time, solar peaks increase energy radiated in 0.01%, peaks go along with more Sun Spots, next peak will come around 2029), the limits of 1.5º C and 1.7º C were actually surpassed.
If I lived in the shore, I'll check the local forecasts in 'Sea Level raise maps', or you risk being forced to sing: '5 feet high and rising', along with Johnny Cash.
Rising tides flooding breaching sea walls to the extent of flooding inland areas.
Breaching to the extent that 3 South Florida counties have gotten together to try and figure out a resolve. Which there doesn't seem one is possible as of yet. Hence they have decided to forgo repairs or raising current sea walls. There are entire neighborhoods in some of the more "prestigious" areas in town being flooded out every high tide. Especially during winter months.
They raised the bridges last year just getting on and off some areas due to the high tide waters.
New development in these areas, which there's plenty, are not telling people that buy homes, or condos about the flooding. The residents nice expensive cars are definitely sercuming to the rath of salt water on metal. Lol... Needless to say, new buyers are rather ticked off not having been told...
I can provide plenty of pics and video of these tidal changes as was predicted more than a decade ago.