Anthropocene


The artist Gabo Guzzo has a new art project called The Geological Turn this project explores the Anthropocene and involves several contributors (most notably Paul Crutzen (Nobel prize winning Chemist) and Jan Zalasiewicz (Geologist and author)).  The residency was at Banner Repeater (which according to the Guardian is one of the best arts venues in north London) and the project continues to be hosted on the blog:

http://thegeologicalturn.tumblr.com/

My own contribution/response shown on the project blog is reproduced below.

The formula in the picture is a standard conservation of mass equation describing landscape evolution, essentially all Earth surface changes in one equation, e.g. uplift, erosion, sediment flux, etc [1].  These natural geomorphic processes operate over geological time periods shaping the landscape – mountain ranges etc.  However, humans have now become the leading geomorphic agents of landscape change [2].  For example, the current rate of sediment transport by humans ellipses that of glaciers and rivers combined.  This simple picture endeavors to capture this concept.  Humankind has literally bulldozed its way into a new geological era, the Anthropocene.

[1] W. E. Dietrich and J. T. Perron, The search for a topographic signature of life, Nature, 439, 411-418, 2006.

[2] R. LeB. Hooke, On the history of humans as geomorphic agents, Geology, 28, 843-846, 2000.

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Here is a neat little animation that illustrates the time history of atmospheric carbon dioxide (CO2) from 800,000 years ago until January, 2011.

The animation begins with the CO2 variability (based on direct measurements from key observation sites) from January 1979 until January 2011.  There are several patterns that are worth noting, firstly the relentless upward trend of the globally averaged carbon dioxide concentration beginning in January 1979 at 336 ppm (parts per million) and ending with a concentration of 391 ppm, the average in January 2011.  Strong inter-annual variability are also evident, particularly in the northern hemisphere – we are essentially seeing the Earth’s breathing pattern!  Fluctuations follow the growing season, peaking in spring with widespread plant greening and minimizing in autumn when biomass is greatest.  During the growing season photosynthesizing plants suck up CO2 whereas during the colder part of the year respiration dominates – plants and animals exhale CO2.  As shown on the graph these fluctuations are far greater in the northern hemisphere than the southern hemisphere (where land area and vegetation cover is much smaller in comparison).

To go back further in time from the preindustrial era to 800,000 years ago requires the careful analyse of ancient air trapped in ice-cores drilled from Greenland and Antarctica.  (Blog posts on detecting past climate information from ice-cores can be read here and here).  Long timescale variability reveals cycles of ~41000 years and ~100000 years, which mark the intervals of glaciations.

Finally, the data clearly shows that current concentrations of atmospheric carbon dioxide are at levels not seen in the last 800 thousand years (and actually most likely not even the past 20 million years).  This rapid rise of atmospheric CO2 to such heightened levels is worrying for our planet and those who (will) live on it.

A major international conference (Planet Under Pressure) is currently underway in London.  The conference has commissioned this 3 minute film, a journey through the last 250 years of history charting the growth of humanity and how we are transforming the planet.

An accompanying website www.anthropocene.info seems to have a very good collection of resources on this topic.