James Lovelock and the Gaia Theory
The scientific insights behind the concept of Gaia, originally termed the Gaia hypothesis, originated with British scientists and inventor James Lovelock around 1965 when he was working at NASA’s Jet Propulsion Lab on a project attempting to detect life on Mars. While working on this project Lovelock and collaborator C.E. Giffin determined that life on other worlds could be detected based on the chemical composition and entropy within the atmosphere, and their findings were published in the journal Advances in the Astronautical Sciences in 1969. It is in this article that we can see the first hints of the Gaia hypothesis in Lovelock’s work.
It is a property of an ecosystem to develop to a steady-state at which the supplies of energy and raw materials set a limit. If the living components of the ecosystem are chemical in form then the fluid media, including the planetary atmosphere, may function as a transfer system for the products of the life cycle.(1)
This idea of a steady-state serves as one of the core ideas behind Gaia and the role of homeostasis, or the ability to maintain certain stable conditions, chief among them being a climate hospitable to life. Early reactions to Lovelock’s ideas were mixed, but this did not stop Lovelock from pressing forward with his idea.
The purpose of this letter is to suggest that life at an early stage of its evolution acquired the capacity to control the global environment to suit its needs and that this capacity has persisted and is still in active use. In this view the sum total of species is more than just a catalogue, “The Biosphere”, and like other associations in biology is an entity with properties greater than the simple sum of its parts. Such a large creature, even if only hypothetical, with the powerful capacity to homeostat the planetary environment needs a name; I am indebted to Mr. William Golding for suggesting the use of the Greek personification of mother Earth, “Gaia”.(2)
Starting in 1974, this idea was expanded upon in articles co-authored with Lynn Margulis, where they attempted to demonstrate that the Earth system as a whole operated as an emergent and living entity which they called Gaia. The two went on to develop this idea in more detail in the coming years, with Lovelock writing several books on the topic, the first of which was Gaia: A New Look at Life on Earth, published in 1979. This popularization of the idea finally brought the idea of Gaia into the public eye, and it was at this point that fellow scientists started to take the idea seriously as a theory.
(1) Lovelock, James and C.E. Giffin. “Planetary Atmospheres: Compositional and other changes associated with the presence of Life.” Advances in the Astronautical Sciences. 25. 1969. pgs. 179–193.
(2) Lovelock, James “Gaia as seen through the atmosphere.” Atmospheric Environment. 6:8. 1972. pgs. 579–580.
The Anthropocene (“recent/new human”) is the name for a newly proposed geologic epoch which was originally proposed by Paul Crutzen and Eugene Stoermer in the IGBP’s Global Change newsletter in 2000. The article, simply called “The Anthropocene.” In this article Crutzen and Stoermer proposed that due to a vast and growing impacts of humans to the planet we have become a force on par with geologic change and forces, and this fact warranted the creation of a new geologic epoch to signal this new relation. They suggested that a good starting point was around 1800, the point in time when our relationship with Carbon began to increase significantly. Here’s an excerpt from their piece about just how big an impact humans are now having on the planet, which is preceded by a long list of human impacts to the land, air, water, soil, atmosphere, communities and ecosystems:
Considering these and many other major and still growing impacts of human activities on earth and atmosphere, and at all, including global, scales, it seems to us more than appropriate to emphasize the central role of mankind in geology and ecology by proposing to use the term “anthropocene” for the current geological epoch…To assign a more specific date to the onset of the “anthropocene” seems somewhat arbitrary, but we propose the latter part of the 18th century…because, during the past two centuries, the global effects of human activities have become clearly noticeable. This is the period when data retrieved from glacial ice cores show the beginning of a growth in the atmospheric concentrations of several “greenhouse gases”, in particular CO2 and CH4. Such a starting date also coincides with James Watt´s invention of the steam engine in 1784…[and]…biotic assemblages in most lakes began to show large changes.(1)
So in short, we should call an end to the Holocene, our current geologic epoch, and herald the emergence of this new epoch, the Anthropocene. You can get some good recent background on this topic from a 2008 GSA article titled “Are We Now Living in the Anthropocene?” There has been much debate about the pluses and minuses of this concept, with a growing body of literature on either side, as well as in between. Right now the IGBP and others have put together a great beginner resource on the science behind the Anthropocene, which you can check out at www.anthropocene.info.
More research and writing about the Anthropocene can also be found here.