It is often assumed that humans began to have a significant impact on the global environment and climate at the dawn of the industrial age in the 18th century, but new research shows that the oldest world was not so intact as one might think.
Scientists analyzing Antarctic ice cores found an unexpected increase in black carbon from soot starting in the late 1200s which can be attributed to New Zealand, where the Maori at the time practiced the burning as a clearing practice.
“Compared to natural burning in places like the Amazon, Southern Africa or Australia, you wouldn’t expect Maori burning in New Zealand to have a big impact, but it does on the Southern Ocean and the Antarctic Peninsula, ”said Nathan Chellman. , postdoctoral fellow at the Desert Research Institute, in a statement. “Being able to use ice core data to show the impacts on atmospheric chemistry that reached the entire Southern Ocean, and being able to attribute that to the arrival and settlement of the Maori in New Zealand 700 years ago was Truly unbelievable.”
Chellman is part of a team that published its findings Wednesday in the journal Nature.
Carbon black is produced by burning biomass. It absorbs light and can contribute to global warming and melting ice caps which can contribute to sea level rise. Chellman’s colleague Joe McConnell, who led the study, was surprised that humans had a significant effect on the atmosphere of centuries before the modern era.
“It is clear from this study that humans have impacted the environment of the Southern Ocean and the Antarctic Peninsula for at least 700 years.”
The results could help reshape our understanding of the atmosphere and climate, as current climate models use information from the climate’s past to predict its future. This study shows that human-caused burns could have a longer lasting impact on the atmosphere, and possibly the climate, and on scales much larger than expected.
“From this study and other previous work our team has done, such as the 2,000-year-old lead pollution in the Arctic from ancient Rome, it is clear that the records of ice cores are very valuable in knowing more about past human impacts on the environment, ”said McConnell. noted. “Even the most remote parts of the Earth were not necessarily pristine in pre-industrial times.”