In June of 1988 I attended the First Chapman Conference on the Gaia Hypothesis held in San Diego, CA. There I was introduced to James Lovelock and a host of other influential scientists studying Gaia, including Lynn Margulis, Stephen Schneider, Tyler Volk, and Lee Kump. My work proposing an ecological mechanism for global cooling caught the attention of Lovelock, who argued at the meeting that “Gaia likes it cold”. That led to my publication of “Peatland formation and ice ages” in the 1991 proceedings volume Scientists on Gaia.
In the 1990s I attended the three Gaia in Oxford meetings (in 1994, 1996, and 1999), which drew scientists like Stephan Harding, Andrew Watson, Susan Canney, Tim Lenton, Peter Westbroek, Euan Nisbet, Bob Charlson, David Schwartzman, David Wilkinson, Stuart Kauffman, Brian Goodwin, and William Hamilton, all of whom have made significant contributions to the science of Gaia.
This was followed by the Second Chapman Conference on Gaia held in Valencia, Spain in 2000, where I presented a paper “Merging Gaia and Complexity”, later published as “Gaia and complexity” in the meeting proceedings Scientists Debate Gaia.
Since then I have attended several conferences sponsored the Geological Society of London Gaia specialty group, including the Feedbacks in the Climate System meeting in 2004, the Life and the Planet meetings in 2011, 2014, and 2015, and the Lovelock Centenary meeting in 2019.
The point of all this is to say that through the 40+ years of involvement in Gaia I have carefully observed and participated in the evolution of Gaian science, and here are my thoughts.
I see four main paths that colleagues have taken in exploring Gaia theory: 1) theoretical Gaia, 2) philosophical Gaia, 3) empirical Gaia, and 4) applied Gaia.
Theoretical Gaia is, nowadays, where all the action is. You can’t really be a part of this path unless you have a mathematical model of the system you are studying. Tim Lenton has championed the modeling approach to Gaia, and his fine skills as a scientist and communicator are a major reason why this area of Gaia has flourished in recent years.
In the late 1990s I dabbled a bit in using coupled non-linear models to shed light on Gaia, and was left feeling daunted at the task of understanding the earth through a math equation, no matter how sophisticated the formulation. All the physical and chemical models I have ever studied are nearly devoid of life. While scientists like Tim Lenton and Richard Betts are making laudable efforts in bringing biological feedbacks into the models, I despair if the future of Gaian science remains solely entrenched in the realm of modeling.
Philosophical Gaia has been explored by thinkers such as Stephan Harding, David Abram, Mary Midgley, and Bruno Latour. Aside from the works of Lovelock and Margulis, the writings on the philosophy and indigenous roots of the living earth concept have, in my view, been the most influential works on Gaia, providing perspectives that inanimate models cannot easily convey to the public. Harding’s book Animate Earth and Midgley’s book Earthy Realism stand out as significant contributions in this area. Recently, Bruno Latour and Tim Lenton proposed a philosophical rethinking of Gaia (Gaia 2.0), one that considers human self-awareness in planetary regulation. This relates not just to modern culture, but also to the ancient living earth worldview and how societies of Indigenous people have been organized around this ‘self-awareness of nature’ concept (Gaia 0.0?).
Empirical Gaia is the basis of Gaian science. It was not a model that first inspired James Lovelock to conceptualize Gaia. It was the empirical observations of the atmosphere of the earth that first got him wondering. The scientific foundations of Gaia are grounded in empirical studies of biogenic gases and sulfur particles in the atmosphere. My own past contributions to Gaia focused on empirical studies of forests and peatlands and their role in carbon cycling, trace gas emissions, and temperature regulation.
Most scientists studying Gaia have made empirical observations a part of their work, although these observations are usually made for the purpose of inclusion into models. While any and all observations related to Gaia are useful, there is a glaring lack of empirical studies that carefully examine any of the proposed biological feedbacks involved in Gaian regulation. In other words, there has never been a true test of Gaia, where all the elements of a proposed regulatory system have been simultaneously examined in situ.
The reason for this is that such an experiment would require a large interdisciplinary field campaign involving dozens of scientists with a broad range of expertise, and significant resources for supporting observational platforms. Unfortunately, Gaia is not the focus of most earth system scientists, and building a coalition of qualified researchers to test Gaia theory is an endeavor that is not likely to happen in the current scientific climate.
Still, it is my opinion that any major advancement in our understanding of Gaia can only come from empirical studies. One day I envision a grand experiment, where scientists on ships, planes, and space stations, and in major ecosystems on all continents, join in the first real-time study of, say, the earth’s circulatory system, or respiratory system, or both. I do believe that day will happen, but probably not in my lifetime.
Applied Gaia is the use of Gaian principles to help solve real world problems. This is a path followed by scientists such as Susan Canney and myself. Canney has applied Gaian principles involving feedbacks of vegetation and wildlife to elephant conservation in Africa, and the success of her work highlights the worthiness of this approach. For my part, I have endeavored to apply Gaian principles involving forest succession to help restore oak forests in California. The positive results I have seen, in turn, reinforce the validity of key assumptions on the role of forest succession in climate regulation of Gaia.
One of the findings that Dr. Canney’s work and my work have in common is the recognition that the past Indigenous practices have played a major role in shaping the ecology of earth’s ecosystems (Applied Gaia). Unfortunately, land management by native peoples has been a major blind spot in Gaia theory. Lovelock rarely mentions Indigenous practices in his writings, and when he does it has not been very sympathetic. For example, in his 2006 book The Revenge of Gaia Lovelock states (p. 144): “the modern Australian aboriginals (are) often claimed to be an example of humans at peace with the earth. Yet their method of clearing forests by fire may have destroyed the natural forests of the Australian continent as surely as do modern men with chainsaws.” I take issue with Lovelock here, and counter that until we consider how Indigenous people may have brought health and vitality to the earth’s ecosystems, we will not be able to properly characterize Gaia.
In lieu of a major effort to test Gaia theory, I believe that Applied Gaia is the next best way to investigate the living earth. If Gaian thinking leads to solutions for real world problems, then that stands as true progress in bringing attention and validity to Gaian science.
I suppose it was inevitable that in the decades since its inception the science of Gaia would diversify into these and other branches of inquiry. A visionary future for a more fertile inquiry into Gaia should include a means by which these branches stay connected, a trunk that is more than an occasional meeting of the minds in London. Perhaps Gaia needs a real home, one that is open to any thinker and scientist who believes Gaia is an idea whose time has come.