Life and the Planet – Part 1

Life and the Planet meeting at the Geological Society of London

I recently attended the Life and the Planet meeting (May 5-6) held at Burlington House, home of the Geological Society of London, of which I am a fellow. In attendance were many of my friends and colleagues from the Gaia in Oxford meetings, including Jim and Sandy Lovelock, Lynn Margulis, Susan Canney, Tim Lenton, Andrew Watson, David Wilkinson, Anne and Mark Primavesi, and Bill Chaloner.

While the meeting had a Gaia theme, the program consisted of a number of speakers mainly from the geological sciences who are new to the discussion of Gaia. In general the speakers did a fair job of characterizing many of the dramatic shifts in earth’s history, such as the great oxygenation event, snowball earth, and the effects of the first plants on the planet, but many avoided mention of feedbacks, regulation, chaos, and complexity.

The one exception, of course, was the opening talk by James Lovelock. His keynote address was masterful, starting with a concise historical overview of Gaia theory for the many newcomers to the debate. He pointed out that the “atmosphere is almost entirely a biological product”. In his unapologetically alarmist voice he warned of “massively harmful climate change”, and suggested that climate change should mobilize science to geoengineer a fix. He then brought Gaia into the discussion of snowball earth by proposing a set of phytoplankton-driven ocean/atmosphere feedbacks involving sulfur pathways that could help drive the onset and termination of ice age conditions. Acknowledging ocean scientist Brian von Herzen in helping formulate this biotic ice age feedback, he stated “We have no notion if it offers a correct explanation but I put it to you as an example of the need for a whole science approach when seeking explanations of planetary scale phenomenon on a live planet like the Earth” (my bold). He then added, “This is especially true of the next catastrophe, the climate change we are now causing by the excessive excretion of CO2.”

The potential role of peatland dynamics in ice-age initiation

As I mentioned in a previous post I am putting up some of my earlier work on feedback mechanisms by which the planet cools itself. This background will be useful in an upcoming post on planetary temperature regulation.

The potential role of peatland dynamics in ice-age initiation

by Lee F. Klinger, John A. Taylor, & Lars G. Franzen

Quaternary Research 45: 89-92 (1996)

Summary – Physical and chemical coupling of peatland vegetation, soils and landforms and atmosphere creates feedbacks which may be important in ice-age initiation. A box diffusion CO2 exchange model shows that a transient forcing of 500Gt C (the amount proposed to have accumulated in peatlands during the last interglacial-glacial transition) over 5000 yr results in a lowering of atmospheric CO2 by about 40 ppm. Proxy data indicate that a decrease in atmospheric CO2 may have occurred over the last 5000 years up to pre-industrial times, and the amount (~22 ppm lowering in 5000 yrs) is similar to that calculated from Holocene peatland expansion. These results suggest that models should consider the role of peatlands in ice-age initiation.

View the entire paper here.

In Fig. 2 (see below) we present evidence that prior to the industrial era atmospheric CO2 was undergoing a decline. We attribute the decline to large-scale landscape transformation involving the replacement of forests by peatlands. Peatlands store immense amounts of carbon and, as described in an earlier publication, are potentially powerful organs that help cool the planet.