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The Lessons of Deep Time

When we talk about the sloooooow carbon cycle, we’re talking about geologic time,  time so deep it’s hard to wrap your head around.

Chocloate pudding cup

When I ran the Camp-In program at the New Mexico Museum of Natural History and Science, we’d end the evening with “Deep-Time-Snack.” Kids made it out of “rock layers” (chocolate pudding) and “fossils” (seaweed chips, goldfish crackers, animal crackers, and Fred or Wilma Flintstone gummies). It was fun. So what if it turned the kids greenish and made them want to barf. It inspired deep thoughts.

Here are some less-barfy ways to think about deep time.

A clock face that shows 4.6 billion years of Earth's events happening in one hour.

I’ve never been a big fan of the clock analogy because you circle back to the “formation of Earth.” Does Earth now blow up so it can re-form?

Timeline of Earths history shown on outstretched arms, fingertip to fingertip.

I prefer the fingertip to fingertip analogy where Earth forms at the tip of your left hand’s middle finger. The present exists at the tip of your right middle finger. (Fill in your own joke now.)

But I’d like to focus on the last 550 million years, just your right hand. Let’s read that palm to tell our past and future.  

Hand as a timeline showing Earth's history in last 550 million years.

  • At your wrist, about 550 million years ago (mya) , we see early shelled organisms.

  • Mid-palm, about 300-400 mya we see fossil fuels starting to form.

  • About 2 mya some apes start using stone tools, early humans.

  • Modern humans appear at the very tip of the fingernail on your middle finger.

If we’re reading our palms to learn about the past and present, it’s clear that the carbon in the fossil fuels we burn in the present, was trapped in the past, a VERY long time ago. Not only that, but you could erase all of the years we’ve been burning those fossil fuels with one swipe of a fingernail file. That's how fast we’re pushing carbon from the slow carbon cycle into the quick carbon cycle!

But that’s not the whole story. We’ve had some big mass extinctions too in the past 550 years too.

Hand as timeline for Earth's history of last 550 million years, including major extinctions.
  • About 65 mya we lost 50% of plants and animals, including non-avian dinos.

  • About 210 mya we lost lots of vertebrate species, allowing dinosaurs to thrive.

  • About 250 mya was the largest mass extinction event - 96% of species lost.

  • About 365 mya many tropical marine species like armored fish wiped out.

  • About 440 mya many trilobites, brachiopods, and other marine organisms died out.



Many would argue we are in the midst of the sixth mass extinction now, as a result of human actions, for example, burning fossil fuels that release ancient carbon into our atmosphere and cause the Earth to heat up. (See Episode 1 of STEM with Cog)

Photo of 2 kids from 1964 movie, "Santa Claus Conquers the Martians"

The future truly is in our hands. But reading our palm is difficult. So much depends on how quickly we tackle the problems of climate change. I think it’s possible humans could survive. But whether we do or not, I hope that millions of years from now, sentient beings on Earth will find a sense of wonder at Deep Time. I hope they make Deep-Time-Snacks that turn their children greenish and make them want to barf.


Pudding: Famartin, CC BY-SA 4.0 <>, via Wikimedia Commons


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