Lecture 45: Human History and the Biosphere
those of the last ice age—but in the opposite direction? We may ¿ nd the
answer to such questions within our lifetimes.In summary, evidence is accumulating that we are now using more resources
than the biosphere can provide, with the risk of a serious breakdown. We
have seen such breakdowns before, but this time it threatens to be global
rather than local. Such conclusions suggest the folly of treating human
history as separate from the history of the Earth. Human history has evolved
within the complex global ¿ lm of life that James Lovelock has called “Gaia.”
Lovelock has argued, controversially, that the entire biosphere constitutes
a single feedback system that has maintained the surface of the Earth in a
state suitable for life. This is a view of evolution in which cooperation seems
more important than competition. Yet Lovelock argues that human activity
may now be threatening the stability of the global “Gaian” system.We have seen that in the course of human history, humans have used more
and more resources at an accelerating rate. Is this a story of triumph, or a sign
of danger? Where is all this going? In the last three lectures of the course we
will try to answer this question by peering into the future. ŶChristian, Maps of Time, chap. 14.
McNeill, Something New Under the Sun.Hughes, An Environmental History of the World.
Turner et al., The Earth as Transformed by Human Action.Essential ReadingSupplementary Reading