La politique optimale de séquestration du carbone par les sols agricoles en France

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• Article - Annals of Economics and Statistics

Résumé

Le protocole de Kyoto, entré en vigueur en février 2005, autorise le recours à des « activités supplémentaires » permettant la séquestration de carbone dans les sols agricoles (article 3.4). Compte tenu de l’importance de ses surfaces agricoles et de ses faibles potentialités de réduction des émissions de gaz à effet de serre à faible coût en raison de ses choix énergétiques, la France peut exploiter cette opportunité. Cette étude analyse la trajectoire optimale de séquestration du carbone par les sols agricoles français. La modélisation développée prend explicitement en compte une caractéristique dominante de la dynamique du stockage de carbone dans les sols: la dissymétrie du processus physique d’accumulation / désaccumulation. Le calibrage du modèle sur données françaises conduit à un résultat très tranché: l’adoption des pratiques séquestrantes doit être pérenne, un stockage additionnel temporaire n’est jamais optimal. Cet exercice empirique montre également combien la politique optimale est sensible, d’une part au coût de la séquestration et d’autre part à la vitesse à laquelle peut s’opérer le basculement vers des pratiques séquestrantes. Les simulations mettent en évidence qu’une politique pérenne de séquestration se traduit par une réduction des émissions annuelles qui n’est que temporaire. Celle-ci reste limitée, en comparaison des objectifs imposés à la France par le Protocole de Kyoto.

Abstract

The Kyoto Protocol, which came in force in February 2005, allows countries to resort to “supplementary activities” consisting, in particular, in the sequestration of carbon in agricultural soils. Considering the importance of its agricultural land and its weak possibilities of low-cost reduction in GHG emissions (given the high nuclear share in electricity generation), France can exploit this opportunity. This paper analyzes the optimal path of carbon sequestration in French agricultural soils. Our model takes into account one of the essential characteristics of the dynamics of carbon storage in agricultural soils: the asymmetry of the sequestration/de-sequestration process. The calibration of the model on French data gives a clear-cut result: the adoption of sequestration practices must be permanent. A temporary sequestration is never optimal. Numerical simulations also show the sensitivity of the optimal policy to sequestration costs and to the bounded number of units of land on which a change of practice can take place at each date. The numerical results demonstrate that a permanent sequestration policy leads to temporary emission reductions. These annual reductions are very limited as compared to the Kyoto objectives for France.

Citation

Ragot, Lionel and Schubert, Katheline, (2009), La politique optimale de séquestration du carbone par les sols agricoles en France, Annals of Economics and Statistics, issue 93-94, p. 7-44, https://EconPapers.repec.org/RePEc:adr:anecst:y:2009:i:93-94:p:5-6.

@ARTICLE{RePEc:adr:anecst:y:2009:i:93-94:p:5-6,
title = {La politique optimale de séquestration du carbone par les sols agricoles en France},
author = {Ragot, Lionel and Schubert, Katheline},
year = {2009},
journal = {Annals of Economics and Statistics},
number = {93-94},
pages = {7-44},
abstract = {The Kyoto Protocol, which came in force in February 2005, allows countries to resort to "supplementary activities" consisting, in particular, in the sequestration of carbon in agricultural soils. Considering the importance of its agricultural land and its weak possibilities of low-cost reduction in GHG emissions (given the high nuclear share in electricity generation), France can exploit this opportunity. This paper analyzes the optimal path of carbon sequestration in French agricultural soils. Our model takes into account one of the essential characteristics of the dynamics of carbon storage in agricultural soils: the asymmetry of the sequestration/de-sequestration process. The calibration of the model on French data gives a clear-cut result: the adoption of sequestration practices must be permanent. A temporary sequestration is never optimal. Numerical simulations also show the sensitivity of the optimal policy to sequestration costs and to the bounded number of units of land on which a change of practice can take place at each date. The numerical results demonstrate that a permanent sequestration policy leads to temporary emission reductions. These annual reductions are very limited as compared to the Kyoto objectives for France.},
url = {https://EconPapers.repec.org/RePEc:adr:anecst:y:2009:i:93-94:p:5-6}
}