Climate Change: So New in Our Human History

One thing that we try hard to convey in our trainings is just how recent the explosion in CO2 levels is, in the context of planetary history or even human history. We believe it's worth focusing on this for several reasons:

- it helps people comprehend our context more accurately - the speed and magnitude of change

- it helps diffuse feelings of wrongness or blame - part of the reason we are struggling to respond to this problem is its very speed relative to our evolution and our past

- it seems to help people absorb that these are not ordinary times, that we, by virtue of when we happened to be born, are called to respond to a unique moment in history.

Over the years we've experimented with a few different ways to convey this time dimension. We show a simple animation of human CO2 emissions for the past 10,000 years (since the beginning of human agriculture) with every second representing 100 years. The animation runs for about a minute and a half, with, of course, nothing happening for the first 87 seconds and then an explosive swing upward of the curve in the final few seconds (final few hundred years). The animation says it better than words can - we live in an unprecedented time.

Next week I'm giving a presentation before a climate change rally, and for technical reasons it won't work to use the animation, so I've been thinking about other ways to convey the time dimension of human-induced climate change.

Here's what I'm thinking of trying:

Imagine the journey of our species from its first emergence in Africa to the current moment as a walk across North America - from San Francisco to New York City. On this journey, San Francisco represents the point of departure, our origins, and New York City represents arriving at our current moment.

I plan to ask the audience to picture where it is in that journey that they would guess we humans begin to burn fossil fuels and disrupt the climate?

Where would you guess? Salt Lake City? Indianapolis?

Even though I know all the numbers I found myself surprised at what my calculations showed:

If the lifetime of Homo sapiens is represented by a 3000 mile journey, the burning of fossil fuels begins about 4 miles from the journey's end. In other words, the long walk from San Francisco, across the Rocky Mountains, the Plains, across the Mississippi, across Appalachia, and into New York State itself, all of that distance represents a period where we were creating culture and art and languages and stories, believing in things and acting in ways that did not disrupt the climate. Only the last four miles of that journey, through the streets of New York City itself represent the period of our experimentation with fossil fuels.

And, to carry the metaphor forward: the next ten years, the years scientists tell us are our window of opportunity for addressing climate change, are represented by just seventy-seven feet. On this long journey our ancestors met the challenges they faced for the metaphorical equivalent of three thousand miles. The next seventy-seven feet are up to us.