John Muir Trust – SEDA Land: online conversation on a carbon tax for land
The newly formed SEDA Land  organised an online conversation on 10 November 2021 in which the John Muir Trust  set out its proposal for a carbon tax on land. Several invited responders then commented on the proposal. Members of the audience asked questions via a chat line.
It was a much needed debate. Land is being degraded and losing its store of carbon in many parts of Scotland. The diagram below was constructed as a step towards completing my understanding of the complexity of interactions linking a carbon tax to land management and hence land-based carbon storage and GHG emissions.
Complex sets of processes are identified as single boxes, some grouped and some linked by arrows. Boxes shaded grey are those that (the author suggests) received most discussion during the Conversation.
Figure 1. Decision trees (simplified) linking interventions on the right (taxation, inducement, management) though land type to biophysical processes (centre) and ‘pillars’ of sustainability.
Change in management inevitably leads to some alteration in the biophysical and social-economic parts of the overall ecosystem and so will have a range of outcomes other than those on carbon and emissions. Some of these outcomes may be unintended or unexpected.
A general feeling at the meeting was that there should be a broad, holistic approach to defining the problem and executing the solutions. Less silo-ing among all parties involved is therefore needed.
Explanation of the diagram
The structure is based on a decision tree of the type created in DEXi software . Starting from the left , the system is divided into biophysical and social-economic attributes (A, B) but there is nothing rigid or fixed in this – other categories could be placed here. Both branches subdivide into other branches (technically called nodes and leaves) which can be extended as needed to include the fine-scale workings of the system. Regulation of carbon and emissions (box C) can only work through the biophysical attributes (e.g. primary production, organic matter breakdown, microbial activity, food webs, element cycling, etc.) which are not shown in detail.
Carbon and emissions are of course not the only high-level attributes linked by biophysical and social-economic processes. All the others – food, industrial products, alcohol, wood, fibre, power – are represented by box D.
Three groups of ‘interventions’ are shown influencing boxes C and D (and hence A and B). First, to the far right, are those related to taxation (G): the boxes within G indicate some of the topics discussed at the meeting, for example, area-thresholds and criteria for defining carbon in land. Taxation, etc. has to operate through land management (box F) – and while the current proposal is slanted towards land of low agricultural productivity, there are strong arguments not to exclude managed grass and arable lands, which can hold much more carbon and emit far less than they presently do. Management interventions operate through land types or classes which are shown in a separate box (E). Change in one land category generally affects what goes on in another.
A particular part of the diagram (at the bottom) alludes to a crucially important set of processes – those that act from outside the region or country but have a great effect inside it. So over-reliance on imports, and purchase of land by external countries and corporations as a means to carbon offsetting, will put a break on internal interventions designed to increase the biophysical and social-economic sustainability of land.
It is essential therefore to include within the set of interventions (G) explicit regulations – here termed global responsibility – that are designed to prevent aggressive purchasing of land within the country and despoilation (including ecocide) in other countries. Interestingly the international crime of ecocide was defined by lawyers earlier in 2021 .
Despite the complexity of the topic, the scientific and technical capability to set criteria and estimate C storage and emissions is within reach. Moreover, the examples given at the meeting of how energy-use can be graded (for example for appliances and domestic housing) and of how taxation has already reduced damage to society, show that the approach proposed by JMT could work.
GR Squire, draft for SEDA 12 Nov 2021, modified and uploaded to curvedflatlands 27 November 2021 (with minor edits 8 December 2021).
More to follow
Sources | links
 SEDA Land’s web site describes the formation of the organisation and gives information on recent and upcoming events https://www.seda.uk.net/seda-land
 John Muir Trust https://www.johnmuirtrust.org/
 DEXi by Marko Bohanec: more on this web site on the functioning of decision trees and links to the software at SEDA Land Conversations.
 Ecocide – The Living Field web site under its DIARY21 lists developments during the present year by those intent on bringing the crime of Ecocide to public attention. DIARY21 gives links to reports and announcements.