News from a Changing Planet -- This Week on Earth #7

Unappreciated (by me) connections: Florida and West Africa, the bottom of a Canadian lake and all of us, and more!

Crawford Lake in Canada, as seen from a drone flight earlier this year. Credit Bonnie Jo Mount, Washington Post

History of the World, Part III: Identifying a beginning of a new geologic age, maybe. (The Washington Post)

In places around the world, stratigraphers and geographers have identified spots that best display the markers of a particular geologic age, a span of time in Earth’s history, or the record of an event that fundamentally changed Earth’s composition. (At least, I think that’s what these markers denote, but geologist readers…please write in with any corrections!) In these sites, they place a golden spike. Earlier this week, scientists decided that Crawford Lake, in Milton, Ontario provides the best evidence for humanity’s impact on the planet, an age they call the Anthropocene.

In the sediment of this lake can be found the traces of human activity since the middle of the 20th century: synthetic fertilizer, radioactive fallout from nuclear weapons testing, burning fossil fuels, deforestation and more. These markers, the scientists say, show the indelible impact the modern age has had on the planet.

Other scientists are hesitant to call the last few decades a new geologic era, though they certainly don’t debate humanity’s impact on the planet. Either way, the placement of this golden spike will have to be debated and voted on by the world’s leading stratigraphers and geologists so…stay tuned.

To me, the unappreciated connection here is between ourselves and the physical history of the planet. It’s easy, maybe, to imagine our plastic waste heading to a landfill, where it will slowly get buried by other trash over time. It’s harder to imagine, decades or centuries on, when that plastic becomes so buried that it becomes bedrock, itself a marker of geologic time. The changes and impacts are cumulative, and there will always be a record of the things we have done. It’s a powerful idea because it connects us in the present to the record of deep time going forward.

Saharan dust traveling across the Atlantic Ocean. In the middle of the dust storm, fewer clouds develop, meaning fewer hurricanes and tropical storms. Credit University of Wisconsin-Madison via The Washington Post

Learning how the puzzle pieces fit together: Florida ocean temperatures and Saharan Dust edition. (The Washington Post)