Invasive species introduced by humans to new areas can also serve as markers, scientists say. San Francisco Bay has been transformed by the inadvertent introduction of alien species into the ballast water of ships arriving in San Francisco from Asia. “At one point, 98 percent of the mass of all animal species in the bay are actually invasive,” Waters said. Pollen from introduced plant species, such as trees used in commercial forests, can also record changes.
Chemical and metal contamination also shows up in sediments, Turner says: “The green revolution was based on artificial fertilizers and pesticides, so you can see that in sediment cores. The whole industrial chemical mix exploded after the war up.” Whether these chemicals will persist in the environment long enough to be a hallmark of the Anthropocene remains to be determined.
The 12 potential locations for the site that will define the new era all show some markers, but they are very different. “Because the Anthropocene hasn’t been formally accepted, we’re still trying to show people that this isn’t localized, it’s something that you find and relate across a large number of different settings,” Waters said.
“They all illustrate this dramatic Anthropocene transition very well. But the sites that really stand out are the ones where you can actually see layers at annual resolution,” Turner said, including some of the lakes, corals and polar ice. Place. “It’s amazing how many of these sites detail planetary changes in their annual resolutions.”
Both have advantages and disadvantages. The 32-meter-long Palmer Ice Core from the Antarctic Peninsula is the longest on record for the Anthropocene, but its remote location means that some marker tracks are often obscure. Baltic Sea sediments changed from light to black with the onset of the Anthropocene. This is caused by algae blooms caused by pollution that suck all the oxygen out of the water. But there is no annual stratification of sediments. Archaeological sites in central Vienna provide a record for 200 years, dated by artefacts, but with gaps in the record due to reconstructions.
The choice of site, and the official time and location of the Dawn of the Anthropocene, is in the hands of the 23 voting members of the AWG, but must then be adopted by the Quaternary Stratigraphy Subcommittee, then by the International Approved by the International Union of Geological Sciences. There is also a deadline: the International Geological Congress in South Korea in 2024, when the AWG’s term expires. “A lot of people are saying we have to get this done by then,” Waters said.
Naomi Oreskes, a professor at Harvard University and a non-voting member of the AWG, said: “As geologists, we are trained to think that humans are insignificant. This was once true, but it is no longer true. Footprints are now evident in rocks and sediments. The Anthropocene is primarily a scientific concept, but it also highlights the cultural, political and economic implications of our actions.”
Mark Maslin, UCL, co-author human planet With Simon Lewis: “I think the Anthropocene is an important philosophical term because it makes you think about what impact we’re having, and what impact we want to have in the future.”
Maslin and Lewis previously proposed that 1610 was the beginning of the Anthropocene, representing the huge and fatal impact of European colonists on the Americas and the world. But agreeing on definitions is more important than pinpointing, Maslin said.
“So far we’ve been talking individually about climate change, the biodiversity crisis, the pollution crisis,” he said. “The key concept of the Anthropocene is to put all of this together and say that humans have a massive impact on the planet, that we are the new geological superpower. Then, this holistic approach allows you to say: ‘What do we do?'”
