jump to navigation

This Date in the Earth Year October 11, 2009

Posted by Jill S. Schneiderman in geologic time.
add a comment

As indicated in an earlier post (September 14), using a calendar year as a metaphor for the 4500 million years of Earth history and employing January 1, New Year’s Day, as the Earth’s birthday, I calculate the current date’s location in the Earth Year and detail what was happening paleontologically at that moment in Earth history.

Today, is day 284 out of 365 days in this (non-leap) year. Not even an entire month has elapsed since my last post on this subject, yet in geologic time, October 11 represents 999 million years ago.  Though we are still in the Proterozoic eon, at this point in earth history single-celled organisms have begun to live together in colonies. Protozoans living in colonies would have occupied more space than protozoans living alone and might have been less vulnerable to challenges of daily living in the late middle Proterozoic. Furthermore, colonial living would have enabled some cells to specialize in certain tasks such as reproduction or locomotion. As a result, colonial protozoans might have had a metaphorical ‘leg-up’ in the late middle Proterozoic over their relatives who lived alone!

Evidence of these ancient colonial protozoans occur as fossilized stromatolites (pictured above). Found in numerous places on earth today, stromatolites are the main sedimentary features of carbonate rocks from earliest Earth history. They are the products of sediment trapping by mat-building microorganisms, known most widely as cyanobacteria. Living stromatolites also occur today but are quite rare because they are subject to predation.

Recycling Coal Ash October 6, 2009

Posted by Jill S. Schneiderman in coal ash, recycling.


Albeit indirectly, Lesley Stahl’s segment of 60 Minutes (4 October 2009), reposted by CommonDreams.org raises two issues that, in my opinion, are very important. The first point is that recycling coal ash is not the panacea that the power industry would like it to be. I believe that the U.S. environmental movement has pushed the slogan “reduce, reuse, recycle” to such an extent that many people believe that most things we use can be recycled. This is not so and coal ash is an example of why everything we use can not be reused or recycled.

There are two great metaphors for the way we think about time: arrows, or time with direction; and cycles, time that endlessly repeats itself. When these two metaphors are combined, we have a realistic way to think about time–cyclic repetition with a difference. The 60 Minute piece brings to my mind the need to focus not preferentially on the cycles of time (and change) but the direction of changes as well. If we do this, we might have a positive and enduring approach to environmental change.

The second point passes in the moment when Lisa Jackson, Administrator of the U.S. EPA, states that she has no data that indicate the safety of certain products made with coal ash (e.g. school room carpeting). The good news embedded in Jackson’s statement is that the Precautionary Principle appears to be Jackson’s point of departure. This is a major change from the way that U.S. society has approached environmental risk in the past, when proof of harm falling on the shoulders of victims was the starting point for changed environmental regulations. Her statement indicates that the Obama Administration is shifting instead to proof of safety being borne by those who advocate “beneficial reuse” of  purportedly innocuous substances before they are ‘repurposed’.

Copenhagen Climate Conference: Cyclic Repetition with a Difference? October 2, 2009

Posted by Jill S. Schneiderman in climate change, geologic time.


As Stephen Jay Gould wrote in Time’s Arrow, Time’s Cycle: Myth and Metaphor in the Discovery of Geological Time (Harvard, 1987), “If moments have no distinction, then they have no interest” (80). Gould proposed this aphorism as a description of the troubled situation that pure visions of time’s cycle impose upon history.

This passage holds significance for me as the world anticipates the upcoming United Nations climate change conference to be held in Copenhagen this December.  Recently in Barbados’ daily newspaper, The Nation, a special two-page section drew readers’ attention to the country’s celebration of World Maritime Day (sponsored by the International Maritime Organization of which Barbados has been a member since 1970). The newspaper reported that the purpose of the day is to focus attention on the importance of the shipping industry, safety, and security, and the marine environment (24 September 2009, 20). The designated theme for World Maritime Day 2009 is climate change.

As an island nation with a heavily developed seashore and nearshore populated by locals as well as visitors, Barbados will face substantial challenges as sea level rises dramatically. Coral bleaching and depletion of seafood here also been linked to climate change. Furthermore, as a water scarce country, climate change also threatens drinking water supply of Bajans and their visitors.

So I’m struck by the overlap of the upcoming UN Conference,  the focus of World Maritime Day and the precarious future portended by unattended climate change. It has me thinking about the cycles and arrows of time. Gould wrote about the model of a large disk rolling along a railroad track  as a metaphor for intertwined arrows and cycles of time (81). Gould points out that cycles advancing as they turn allow for history. As his proposed aphorism states, moments without distinction have no interest. Without a way to distinguish between a particular stage in the cycle, we are unanchored in time. Everything comes round again, as Gould says (80).

For time  to be truly meaningful, it must be more than cyclic repetition. But “cyclic repetition with  a difference” as Gould refers to it combines time’s cycle with time’s arrow. Among the speechifying that may occur at Copenhagen, I would anticipate declarations of “now is the time,” exhortations to take action to curb greenhouse gas emissions immediately. It’s likely that speakers will extol the virtue of quick action because of our previous inattentiveness to increased greenhouse gas emissions and consequent global warming. Clearly time plays a significant part in this global conversation. The idea that there is urgency to the climate change talks, means the subject is climate change through time, not simply climate change in space.

My mind runs to the 1997 Kyoto Conference on Climate Change. How did the verbiage of that meeting go? Will verbiage at the Copenhagen conference sound the same as Kyoto? If so we will have nothing more than cyclic repetition or in Gould’s words, time’s cycle without time’s arrow.

Are we trapped in the view of climate change constrained by a dominant view of the Earth system as a system of endlessly renewing cycles? Carbon cycle, hydrologic cycle, nitrogen cycle, rock cycle, plate tectonic cycle. Reduce, Reuse, Recycle? With such an emphasis on reusing and recycling, maybe we may have lost sight of time’s arrow– the role that distinctive events play in making history.

Many factors indicate that we are not at the same place in the decision cycle pre-Copenhagen as we were pre-Kyoto. Global temperature is warmer, weather more disrupted, sea level higher. We should behave at Copenhagen in a way consistent with this reality. With such a consciousness, we can act on the arrow as well as the cycles of time as they relate to climate change.