Skip to main content

The Most Accurate Clock Is A Tree: Keeping Time With Nature

A clock with roman numerals and hands pointing to the time 6:55 is painted on the inner wood of a tree trunk where the bark has been removed
We can look at living trees to tell time, as they're natural calendars with the growth of a new ring every year. | kwasny221/Getty Images/iStockphoto
Growing on remote mountaintops, the oldest living bristlecone pines have been tracking time for 5,000 years. Their annual rings have much to tell us about past climate conditions. Could they also calibrate our future actions?
Support Provided By

This article is part of a series, in collaboration with the Civic Paths working group at the University of Southern California.

In pre-Classical Greece, time was kept by cicadas' songs and the flowering of artichokes and the migration of cranes. Ballads recounted these annual events and provided their interpretation. Constellations also provided guidance, but celestial authority was contingent. Days were arbitrarily added as the stars fell out of sync with nature.

Gradually, society made calendars more regular. First, the moon was used, and then the sun. Julius Caesar improved the reliability of solar timekeeping by introducing the leap year. We're now on the Gregorian calendar and Coordinated Universal Time, in which the year is exactly 365.2425 days in duration, as calibrated by atomic clocks with an accuracy exceeding one second every hundred million years.

Of course, the Gregorian calendar and Coordinated Universal Time are useful for keeping appointments and managing multinational corporations. They support industrial development and economic efficiency.

The question is whether this techno-capitalist world is one we want to inhabit — and whether it's a world that will remain habitable for much longer.

Here’s an alternative plan: Instead of observing atoms or stars, we can look at living trees.

An ancient-looking tree appears to have three trunks as it stands, somewhat falling over, on a dry landscape under a blue sky with white, puffy clouds
What if we were to allow a bristlecone pine tree — the longest-living complex organism on the plant — to tell us what time it is? | Chris Murphy

Trees are natural calendars. Every year, they grow a new ring — and you can determine their age by counting. But that's not all the rings indicate.

As dendroclimatologists have learned, the thickness of each ring is a measure of environmental conditions in a given year. So, the growing girth of the tree is an indication of time — but one that varies with the changing climate.

Imagine a sapling. Imagine a young bristlecone pine tree with an expected lifespan of as many as 5,000 years. Around that tree — which happens to be the longest-living complex organism on the planet — you might set markers made out of stone, regularly spaced in 500-year increments based on the estimate girth of the tree in 500 years, 1000 years and more. That is, if the future growth rate were to remain the same as in the present because the climate didn't change.

Then you might stand back — and give the tree authority.

What if we were to choose to live on bristlecone time?

The tree will almost certainly grow out of sync with Gregorian years. For instance, if it grows faster in the future because of rising carbon dioxide, it may tell you that the year is 3500 when your smartwatch says it's 3127.

What if we were to accept what the tree says? What if we were to choose to live on bristlecone time?

The bristlecone year could easily be subdivided into shorter increments: months, days, hours, minutes, seconds. For practical purposes, the time kept by the tree could be indicated on a municipal clock. Or, a time signal could be distributed through an internet protocol equivalent to Network Time Protocol used to synchronize computer systems today. This arboreal protocol would allow people to put their smart watches, their computers, and their entire lives onto bristlecone time.

The planet would have a new time standard. A standard that would be anything but standard.

Time would be irregular. The planning of future events would be uncertain.

A rendering shows the internal mechanism of a clock in various gears represented by overlapping circles
A rendering of the bristlecone-calibrated clock that the author is developing at the Nevada Museum of Art in collaboration with the Long Now Foundation. | Nevada Museum of Art

Why would anyone create such a counterintuitive timekeeping system? There are several good reasons.

First, when we superimpose atomic time on the planet, we implicitly assert control over the world. We take charge of nature. And looking at the environmental ruin of the Anthropocene, that doesn't seem to be turning out so well.

Second, the regular time of atomic clocks gives us the false illusion of being able to forecast the future. With a bristlecone clock, time is alive with contingencies, and we come to terms with where prediction fails us: the limitations of what we can know about the future, and the threat of hubris.

Third, with the bristlecone clock, there is the possibility of interacting with deep time. There's the possibility of changing the future based on our present behavior.

Our actions will affect bristlecone time. And while we need to be aware of our hubris, we also need to be aware that we have choices and responsibilities. Arboreal time can provide us with an ecological feedback mechanism. The bristlecones can calibrate our time on this planet.

Jonathon Keats is currently developing a bristlecone-calibrated clock at the Nevada Museum of Art in collaboration with the Long Now Foundation.

Support Provided By
Read More
An oil pump painted white with red accents stands mid-pump on a dirt road under a blue, cloudy sky with a green, grassy slope in the background.

California’s First Carbon Capture Project: Vital Climate Tool or License to Pollute?

California’s first attempt to capture and sequester carbon involves California Resources Corp. collecting emissions at its Elk Hills Oil and Gas Field, and then inject the gases more than a mile deep into a depleted oil reservoir. The goal is to keep carbon underground and out of the atmosphere, where it traps heat and contributes to climate change. But some argue polluting industries need to cease altogether.
Gray industrial towers and stacks rise up from behind the pitched roofs of warehouse buildings against a gray-blue sky, with a row of yellow-gold barrels with black lids lined up in the foreground to the right of a portable toilet.

California Isn't on Track To Meet Its Climate Change Mandates. It's Not Even Close.

According to the annual California Green Innovation Index released by Next 10 last week, California is off track from meeting its climate goals for the year 2030, as well as reaching carbon neutrality by 2045.
A row of cows stands in individual cages along a line of light-colored enclosures, placed along a dirt path under a blue sky dotted with white puffy clouds.

A Battle Is Underway Over California’s Lucrative Dairy Biogas Market

California is considering changes to a program that has incentivized dairy biogas, to transform methane emissions into a source of natural gas. Neighbors are pushing for an end to the subsidies because of its impact on air quality and possible water pollution.