Assessing the efficiency of changes in land use for mitigating climate change

Searchinger Timothy D., Wirsenius Stefan, Beringer Tim, Dumas Patrice. 2018. Assessing the efficiency of changes in land use for mitigating climate change. Nature, 564:7735 : 249-253.

Url - jeu de données - Entrepôt autre : https://doi.org/10.1594/PANGAEA.893761 / Url - jeu de données - Entrepôt autre : https://github.com/PIK-LPJmL/LPJmL

Quartile : Outlier, Sujet : MULTIDISCIPLINARY SCIENCES

Liste HCERES des revues (en SHS) : oui

Thème(s) HCERES des revues (en SHS) : Economie-gestion; Psychologie-éthologie-ergonomie

Résumé : Land-use changes are critical for climate policy because native vegetation and soils store abundant carbon and their losses from agricultural expansion, together with emissions from agricultural production, contribute about 20 to 25 per cent of greenhouse gas emissions1,2. Most climate strategies require maintaining or increasing land-based carbon3 while meeting food demands, which are expected to grow by more than 50 per cent by 20501,2,3,,2,4. A finite global land area implies that fulfilling these strategies requires increasing global land-use efficiency of both storing carbon and producing food. Yet measuring the efficiency of land-use changes from the perspective of greenhouse gas emissions is challenging, particularly when land outputs change, for example, from one food to another or from food to carbon storage in forests. Intuitively, if a hectare of land produces maize well and forest poorly, maize should be the more efficient use of land, and vice versa. However, quantifying this difference and the yields at which the balance changes requires a common metric that factors in different outputs, emissions from different agricultural inputs (such as fertilizer) and the different productive potentials of land due to physical factors such as rainfall or soils. Here we propose a carbon benefits index that measures how changes in the output types, output quantities and production processes of a hectare of land contribute to the global capacity to store carbon and to reduce total greenhouse gas emissions. This index does not evaluate biodiversity or other ecosystem values, which must be analysed separately. We apply the index to a range of land-use and consumption choices relevant to climate policy, such as reforesting pastures, biofuel production and diet changes. We find that these choices can have much greater implications for the climate than previously understood because standard methods for evaluating the effects of land use4,5,6,7,8,9,10,11 on greenhouse gas emissions systematically underestimate the opportunity of land to store carbon if it is not used for agriculture.

Mots-clés Agrovoc : changement climatique, utilisation des terres, réduction des émissions

Mots-clés libres : Land-use change, Climate change mitigation

Classification Agris : P40 - Météorologie et climatologie
P01 - Conservation de la nature et ressources foncières
E11 - Économie et politique foncières

Champ stratégique Cirad : Axe 6 (2014-2018) - Sociétés, natures et territoires

Auteurs et affiliations

• Searchinger Timothy D., Princeton University (USA) - auteur correspondant
• Wirsenius Stefan, Chalmers University of Technology (SWE)
• Beringer Tim, Humboldt Universität zu Berlin (DEU)
• Dumas Patrice, CIRAD-ES-UMR CIRED (FRA) ORCID: 0000-0002-3896-7589

Source : Cirad-Agritrop (https://agritrop.cirad.fr/590616/)

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