Canadian Forest Service Publications

Reconciling global-model estimates and country reporting of anthropogenic forest CO2 sinks. 2018. Nature Climate Change, 8, pp.914–920.

Year: 2018

Available from: Pacific Forestry Centre

Catalog ID: 39355

Language: English

CFS Availability: PDF (request by e-mail)

Available from the Journal's Web site.
DOI: 10.1038/s41558-018-0283-x

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Abstract

Achieving the long-term temperature goal of the Paris Agreement requires forest-based mitigation. Collective progress towards this goal will be assessed by the Paris Agreement’s Global stocktake. At present, there is a discrepancy of about 4 GtCO2 yr−1 in global anthropogenic net land-use emissions between global models (reflected in IPCC assessment reports) and aggregated national GHG inventories (under the UNFCCC). We show that a substantial part of this discrepancy (about 3.2 GtCO2 yr−1) can be explained by conceptual differences in anthropogenic forest sink estimation, related to the representation of environmental change impacts and the areas considered as managed. For a more credible tracking of collective progress under the Global stocktake, these conceptual differences between models and inventories need to be reconciled. We implement a new method of disaggregation of global land model results that allows greater comparability with GHG inventories. This provides a deeper understanding of model–inventory differences, allowing more transparent analysis of forest-based mitigation and facilitating a more accurate Global stocktake.

Supplementary Information

Plain Language Summary

In 2023, the UNFCCC Global Stocktake will assess collective progress towards reducing greenhouse gas concentrations in the global atmosphere. This paper examines the reasons for a ~4 billion ton carbon dioxide equivalent (CO2e) per year difference in the scientific (IPCC) estimates of land sector contributions to the global carbon budget and land sector estimates obtained from National Greenhouse Gas Inventories. The reasons for this discrepancy are explained, the contributions from the different conceptual approaches to managed lands are estimated, and suggestions for reconciling the differences are provided. The paper shows that a substantial part of this discrepancy (about 3.2 GtCO2 yr−1) can be explained by conceptual differences in anthropogenic forest sink estimation, related to the representation of environmental change impacts and the areas considered as managed. For a more credible tracking of collective progress under the Global Stocktake, these conceptual differences between models and greenhouse gas inventories need to be reconciled. The study implements a new method of disaggregation of global land model results that allows greater comparability with greenhouse gas inventories. This provides a deeper understanding of model–inventory differences, allowing more transparent analysis of forest-based mitigation and facilitating a more accurate Global Stocktake.

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