Imputation of missing land carbon sequestration data in the AR6 Scenarios Database

<p>The AR6 Scenarios Database is a vital repository of climate change mitigation pathways used in the latest Intergovernmental Panel on Climate Change (IPCC) assessment cycle. In its current version, many scenarios in the database lack information about the level of anthropogenic carbon dioxid...

Full description

Saved in:
Bibliographic Details
Main Authors: R. Prütz, S. Fuss, J. Rogelj
Format: Article
Language:English
Published: Copernicus Publications 2025-01-01
Series:Earth System Science Data
Online Access:https://essd.copernicus.org/articles/17/221/2025/essd-17-221-2025.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:<p>The AR6 Scenarios Database is a vital repository of climate change mitigation pathways used in the latest Intergovernmental Panel on Climate Change (IPCC) assessment cycle. In its current version, many scenarios in the database lack information about the level of anthropogenic carbon dioxide (CO<span class="inline-formula"><sub>2</sub></span>) removal via land sinks, as net-negative CO<span class="inline-formula"><sub>2</sub></span> emissions and gross removals on land are not always separated and are not consistently reported across models. This makes scenario analyses focusing on CO<span class="inline-formula"><sub>2</sub></span> removal challenging. We test and compare the performance of different regression models to impute missing data on land carbon sequestration for the global level and for several sub-global macro-regions from available data on net CO<span class="inline-formula"><sub>2</sub></span> emissions from agriculture, forestry, and other land uses. We find that a <span class="inline-formula"><i>k</i></span>-nearest neighbors regression performs best among the tested regression models and use it to impute and provide two publicly available imputation datasets (<a href="https://doi.org/10.5281/zenodo.13373539">https://doi.org/10.5281/zenodo.13373539</a>, Prütz et al., 2024) on CO<span class="inline-formula"><sub>2</sub></span> removal via land sinks for incomplete global scenarios (<span class="inline-formula"><i>n</i>=404</span>) and incomplete regional R10 scenario variants (<span class="inline-formula"><i>n</i>=2358</span>) of the AR6 Scenarios Database. We discuss the limitations of our approach, the use of our datasets for secondary assessments of AR6 scenario ensembles, and how this approach compares to other recent AR6 data reanalyses.</p>
ISSN:1866-3508
1866-3516