[beloch]

Honestly, it is hubris to start the anthropocene in just the last human lifetime. Our species has been making an impact that will be evident in the geological record for longer than that.

e.g. Geologists of some far-off future are going to notice that species that were isolated to one continent suddenly started popping up everywhere in the fossil record a few hundred years ago. Sea travel has united the continents in way they haven't been united since Pangea.

A few hundred years will be indistinguishable from a single human lifetime to those future geologists. To us however, it's an important distinction.

[userulluipeste]

"A few hundred years will be indistinguishable from a single human lifetime to those future geologists."

On what do you base this claim? Before humans, not much happened around and the sediment layers were thin. The amount of energy moving things around was limited to weather (due to sun radiation, mostly), volcanic/tectonic activity, and to (a lesser degree, due to direct effect of) tidal forces. Humans activity however, both directly and indirectly, caused effects that also involved energy stored in the span of millions of years. That should be anything but indistinguishable.

Also, from the article: "The amount of sediment settled behind the world’s thousands of big dams would cover all of California to a depth of five meters, and such sediments are full of distinctive markers, like pesticide residues, metals, microplastics and the fossils of invasive species. To define a time period formally, geologists must identify distinctive signals in sediments or rocks that can be correlated around the globe, and the presence of such markers is ubiquitous. The geology is real."

[parineum]

> like pesticide residues, metals, microplastics and the fossils of invasive species.

How much of that stuff is going to survive on geological timescales amd the concept of "invasive species" isn't really applicable to anything but conservationists that want to maintain a static environment.

[Twisell]

Much will survive even if it will eventually transform. But that's not unlike petroleum which is composed of fossilized organic materials.

Wether the result will be useful or detrimental to future generations is yet another question that we deferred to them.

[AdamN]

Agreed. Spain's old growth forests were denuded to build the Spanish Armada (or thereabouts) and you can go further back to catastrophic, anthropogenic, environmental shifts a few thousand years back in India, China and elsewhere in the world. Geology isn't focused on single year boundaries so maybe it's best to say that we entered the Anthropocene 6k-2k years ago (a 4k year range).

[southernplaces7]

Spains (and much of Europe's) old growth forests were also almost completely denuded much earlier than that to build most of the Roman Empire, and its vast mining operations, naval flotillas and so forth. Yet they grew back to again disappear roughly around the Renaissance over 1000 years later.

The interesting thing is that many modern popular social discussions (and even some pop sci arguments) speak of old growth forests as irreplaceable things that, if cut down, pretty much disappear when history clearly shows that this isn't true.

I don't defend cutting them down just because, but I think it's good to be honest about their ability to come back.

[willis936]

Zooming in to the right of the graph: there's noise then there's signal.

https://ourworldindata.org/co2-emissions

[tim333]

We seem to have wiped out most of the 'charismatic megafauna' from about 10,000 years ago. Mammoths, dodos etc.