The secrets of the Antarctic ice unfold like an ancient scroll, telling us the wonderful interweaving of atmosphere and life. Scientists have discovered a surprising phenomenon in this frozen world: there is a mysterious link between past atmospheric carbon dioxide levels and centuries-old global pandemics. It makes us wonder just how much humanity – or the lack thereof – has on the planet.
The bubbles encased in ancient ice are like small capsules sealed in time, containing secrets in the atmosphere thousands or even millions of years ago. They are like witnesses of history, silently recording the earth's climate change.
Over the past 2,000 years, we have two valuable records: the Antarctic ice "mound" law dome and the West Antarctic ice sheet dividing ice cores. These two records complement each other and give us a picture of what it was like to be in that era. It was a time of rising empires, the eruption of Mount Vesuvius, the recording of unknown souls in parchment scrolls, and the constant wars of people across Europe for territory and faith. At the same time, diseases such as plague and syphilis continue to rage, claiming countless lives.
During this period, Law Dome and Wais Divide ice cores provided us with valuable data. Although there are some differences in the measurement of atmospheric carbon dioxide, these differences reveal more information for us. For example, the Law Dome core shows that carbon dioxide levels fell rapidly in just 90 years, reaching their lowest level in 1610. This is similar to the consequences of the first contact between the Old and New Worlds, when the disease brought by Columbus killed dozens of indigenous people, and the Europeans faced the same fate when they returned to Europe. Scientists believe that the outbreaks of these epidemics have led to a sharp decline in populations, which may have led communities to abandon their previous habitats and allow vegetation to recover. These newborn vegetation absorb large amounts of carbon dioxide from the atmosphere, leaving measurable traces in the Law Dome ice cores.
However, the data at the core of WAIS Divide shows a different trend. Its carbon dioxide levels did not decline sharply, but showed a gradual downward trend that lasted until the 17th century. To explain this discrepancy, paleoclimatologists Amy King and colleagues at the British Antarctic Survey decided to take a deeper look. They chose a single ice core – the Skytrain ice core – for the measurement of carbon dioxide levels. The ice core was drilled in 2018-2019 from the edge of the West Antarctic ice sheet.
King and colleagues conducted a detailed analysis of the Skytrain ice core, which ranged from 83 to depth2 meters to 104 meters, capturing gas samples from 1454 to 1688 AD. The results of their analysis showed that carbon dioxide levels did decline during this period, which may be related to changes in population and land vegetation. However, the rate of this decline is much slower than the Law Dome ice cores indicate.
King and colleagues write in **: "Our analysis supports a gradual decrease of 05 ppm (parts per million). They further noted that as the population declines and forests regenerate, about 2.6 billion tonnes of carbon dioxide can be absorbed every decade. This discovery "confirms a simulated scenario of large-scale land-use restructuring in the Americas after the New World came into contact with the Old World." ”
Subsequently, the team simulated atmospheric carbon fluxes using data from each ice core and simulated possible changes in terrestrial vegetation in combination with known rough population estimates. After intensive study, they came to a surprising conclusion: the rapid reduction in carbon dioxide seen in the Law Dome ice core at 1610 CE was "incredibly large" and "incompatible with even the most extreme land-use change scenarios." This means that, in addition to human activity, there may be other unknown climate carbon feedback events that may have contributed to the lowest CO2 values recorded by the Law Dome.
This discovery not only gives us a deeper understanding of the history of the planet, but also reminds us that humanity's relationship with the planet is far more complex than we think. In this world full of unknowns, we are both observers and participants, and our every action is shaping the future of this planet.