DOI: 10.5281/zenodo.13777078
title: Global warming effects of cropland expansion by reduction of biogenic secondary organic aerosols

description: This is the dataset to support our paper title of “Global warming effects of cropland expansion by reduction of biogenic secondary organic aerosols”. Cropland expansion has been the most significant global land use change since industrialization. However, evaluations of radiative forcing from land use changes have often neglected the radiative effects of secondary organic aerosols (SOA) linked to cropland expansion. Sensitivity experiments using an Earth system model that incorporates advanced SOA processes reveal approximately a 10% reduction in the global biogenic SOA burden due to cropland expansion since industrialization. This reduction weakens SOA’s role in scattering radiation and forming clouds, leading to a decline in its cooling effect by 146 mW m⁻², which is equivalent to 8% of the warming caused by CO₂ emissions since industrialization. This effect is expected to increase by nearly half under future climate warming and reduced emissions scenarios. Therefore, policies addressing food security and climate change must consider the radiative impacts of biogenic SOA associated with cropland expansion.

 

The dataset consists of three zip files, which include model code and output from sensitivity simulations conducted with the Community Earth System Model (CESM) version 1.2.2, using the IMPACT aerosol module and an offline radiative model. The files are described as follows:

 

Model code.zip: Contains the source code for the IMPACT aerosol module, which was integrated as an additional aerosol module within CESM version 1.2.2, available from the NCAR repository.

 

PD_Cases.zip: This file contains two folders (Concentration and Radiation), which hold the simulation results for concentration and radiation in present-day cases. The Concentration folder includes 13 subfolders. The Radiation folder contains four subfolders representing different radiation simulation results. These include simulations with and without the direct radiative effects of SOA (labeled ADEwSOA and ADEwoSOA respectively) and simulations with and without the indirect radiative effects of SOA (labeled AIEwSOA and AIEwoSOA respectively). Each of these subfolders contains 13 additional subfolders, which share the same names as those in the Concentration folder. These 13 subfolders correspond to specific sensitivity experiments, the details of which are explained below. Within each subfolder, you will find the five-year averaged model output for all 12 months.

18L20E20C represents simulations with pre-industrial land use, and present-day emissions and climate conditions; 

20L20E20C represents simulations with present-day land use, emissions, and climate conditions.

Eight subfolders for single vegetation type transition experiments include model output for cases where land use transitions from deciduous broadleaf forest to cropland (DBF2CRO), evergreen broadleaf forest to cropland (EBF2CRO), evergreen needleleaf forest to cropland (ENF2CRO), grassland to cropland (GRA2CRO), shrubland to cropland (SHR2CRO), deciduous broadleaf forest to grassland (DBF2GRA), evergreen broadleaf forest to grassland (EBF2GRA), and evergreen needleleaf forest to grassland (ENF2GRA).

Three subfolders for latitude-specific experiments cover conversions for all vegetation types in tropical (20°S–20°N, LLAT), mid-latitude (50°S–20°S and 20°N–50°N, MLAT), and high-latitude (south of 50°S and north of 50°N, HLAT) regions.

 

FU_Cases.zip: This file contains two folders (Concentration and Radiation), which hold the simulation results for concentration and radiation in future cases. The Concentration folder includes 4 subfolders. The Radiation folder contains four subfolders representing different radiation simulation results. These include simulations with and without the direct radiative effects of SOA (labeled ADEwSOA and ADEwoSOA respectively) and simulations with and without the indirect radiative effects of SOA (labeled AIEwSOA and AIEwoSOA respectively). Each of these subfolders contains 4 additional subfolders, which share the same names as those in the Concentration folder. These 4 subfolders correspond to specific sensitivity experiments, the details of which are explained below. Within each subfolder, you will find the five-year averaged model output for all 12 months.

18L20E21C represents simulations with pre-industrial land use, and present-day emissions, and future climate conditions; 

18L21E21C represents simulations with pre-industrial land use, future emissions, and future climate conditions;

20L20E21C represents simulations with present-day land use, and present-day emissions, and future climate conditions; 

20L21E21C represents simulations with present-day land use, future emissions, and future climate conditions.