By Mark Williams

About Mark Williams

Mark Williams is a geologist with a particular interest in the reconstruction of ancient climate. One area of his research has focused on the climate of the Pliocene world, some three million years ago, when CO2 levels were similar to their levels in the present. Williams is a former geologist with the British Geological Survey and British Antarctic Survey, and his geological expertise has taken him from the Cambrian to the Anthropocene, and from the tropics to the Antarctic. He teaches palaeoclimates and micropalaeontology at the University of Leicester in the United Kingdom.


The world today is undergoing rapid environmental change, driven by human population growth and economic development. This change encompasses such diverse phenomena as the clearing of rainforests for agriculture, the eutrophication of lakes and shallow seas by fertilizer run-off, depletion of fish stocks, acid rain, and global warming. These changes are cause for concern—or alarm—among some, and are regrettable if unavoidable side effects of economic growth for others.

How significant are these changes in total? How might they evolve, and what might their ultimate consequences be? One way of studying these changes is to consider them as the latest phase of the many environmental changes that have affected the Earth since its origin, a little over four and a half billion years ago. Humans may be considered as geological agents, and anthropogenic environmental change may be compared with events in Earth’s deep history.

Such analysis dates, perhaps surprisingly, from the …

Pages ·