Scientists at Cardiff University have found that if the volume of carbon dioxide emissions remains the same, then by 2100 the acidification (acidification) of the oceans will reach levels unprecedented in human history. Researchers estimate that the pH of seawater will drop below 7.8, which has not been observed for the past 14 million years. This was announced in a press release on Phys.org.
With ocean acidification, the pH decreases, which is caused by the dissolution of carbon dioxide from the atmosphere in seawater. According to the World Meteorological Organization, the acidification rate is currently the highest in the last 300 million years. This threatens the existence of coral reefs and shell-bearing animals, and could lead to the extinction of modern marine ecosystems.
Scientists have analyzed the changes in the acidity of the oceans that have taken place over 22 million years. To do this, they studied the fossils of shell marine animals that lived in the near-surface sea waters. The chemical composition of the shells helped determine the pH at various times. These data were combined with measurements of atmospheric carbon dioxide levels to predict future acidification levels.
It turned out that by 2100, if the rate of greenhouse gas emissions continues, the concentration of carbon dioxide will reach 930 parts per million, compared with the current 400 parts per million. This corresponds to a decrease in the pH value from 8.1 to 7.8. According to the researchers, this was last observed only in the Miocene era, when the average temperature of the Earth's atmosphere was three degrees Celsius higher than it is now. However, acidification now occurs not as a result of the natural cycle, but as a result of human activity, which has been proven by climate research.
According to climatologists and geologists, the situation with rapid climate change, observed now, is fundamentally different from natural cycles in the history of the Earth. A sharp catastrophic increase in carbon dioxide levels arising from increased volcanic activity leads to the disappearance of ecosystems and mass extinctions. So, experts associate the Early Cambrian extinction 510 million years ago with volcanic eruptions in Australia. Slow climate changes contribute to the emergence of new adaptations and are not so destructive for living organisms.