In recent months and even years, the warnings from the State Meteorological Agency (Aemet), the Copernicus Climate Change Service (C3S), NASA or the World Meteorological Organization itself launch historical temperature warnings and add the tagline “since there are records.” Some date from 1960, others from 1940 and some of them date back to 1850. “I sometimes work on the Upper Cretaceous and that is 65 million years,” responds José-Abel Flores, paleoclimatologist and professor in the Department of Geology at the University of Salamanca.
However, “you can go further back,” he states with certainty on the other end of the phone. Flores searches the depths of the sea to look for answers to current questions and finds them. “The Atlantic is 100 million years old and the Pacific is about 170 million years old,” she explains. On their seabed, the oceans hide sedimentary rocks that have records of past times, “what happens is that they move and remain buried during cycles of millions of years. Flores along with colleagues from the Integrated Ocean Drilling Program (IODP) travel seas and oceans searching for oxygen isotopes. “What we do is the same as what happens in Antarctica, but extracting ice cores,” she says.
Through drilling into the seabed, paleoclimatologists travel back in time. “We have fossil bubbles from the atmosphere from 1.2 million years ago,” he notes. These small concentrations allow these researchers to know the temperature of the earth at that time and also the concentration of gases in the atmosphere. “It is an absolutely reliable record,” he adds.
José Abel’s historical archive dates back to a million years ago, “there we are aware of a large concentration of CO2,” he explains. A library that is made up of thousands of microscopic ‘bugs’ collected every “five centimeters” of the seabed. “You can also see tree rings or even coral reefs,” he explains. The organisms collected by Flores’ team “float and collect all the information about their environment and it is recorded in their calcium carbonate shell,” says the scientist. When they die they fall to the bottom and are ‘rescued’ there to discover the records of the past. A foray into history as if it were a book. “It is a complex engineering technique, but we are literally separating sheet by sheet in a microscopic way,” he details.
«We have fossil bubbles from the atmosphere from 1.2 million years ago»
José-Abel Flores
paleoclimatologist
This is how we get to 40 million years ago, “this is what we know as the Paleocene or Eocene,” says Flores, “the concentration of carbon dioxide in the atmosphere was 3,000 parts per million and “there was also a lot of methane,” he warns. “The “Temperatures were 12 degrees above average and caused ocean organisms to modify their ecosystem, but this occurred due to a series of volcanic explosions,” he noted.
These small organisms are not the only paleodata that warn of warming of the Earth. “Ice cores from Antarctica speak of a concentration of 285 parts per million of CO2 1.2 billion years ago and temperatures were high,” he explains. “Now that natural carbon dioxide should have those figures,” he points out. The difference is that the figure almost multiplies: “A few days ago I looked at it and in the Pacific it was 414 parts per million and that causes the temperature of the ocean and the planet to rise. “It is the pattern that the paleoclimate gives us and all this has been happening for 50 years.”
Historical changes
Throughout the history of the planet, paleoclimatic records have demonstrated cycles of rises and falls in temperature. “The Vikings arrived in Newfoundland in the 11th century, because there was an optimal climate that raised temperatures and then they had to leave the place,” he reveals. According to his explanation, this was due to solar cycles. After the optimal climate, then came a cold period: “we know more or less that when Cervantes wrote ‘Don Quixote’ it was very cold,” says Flores. “Then another warm one came,” she adds.
But what has happened in the last half century, Flores highlights, is that “it’s going bad.” According to historical patterns, right now, we should have a time with lower temperatures. “It is rising much higher than what was particularly planned, and it is beginning to be very worrying,” warns the professor at the University of Salamanca. “The last decade is much higher than usual and we do not know how the planet can react because we lack data,” he adds. It is clear that “human action is modifying conditions, but we do not know when and how the final reaction may be, we do not know,” he points out.
Scientific models assure that maintaining the planet’s temperature at 1.5ºC compared to the pre-industrial era would maintain balance, “but we are late,” says Flores.
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