Global Gridded Crop Model Intercomparison (GGCMI) Project

The GGCMI Initiative brings together a diverse international community of crop modelers for climate impact assessment, model intercomparison and improvement at the global scale.

Background and Motivation

In 2012, AgMIP led a GGCM Intercomparison fast-track project in coordination with the Inter-Sectoral Impacts Model Intercomparison Project (ISI-MIP). This fast-track included 7 GGCMs and focused on updating the state of knowledge on climate change vulnerabilities, impacts, and adaptations using the most current library of climate model outputs (CMIP5). The fast-track culminated with the submission of 6 papers to a special issue of PNAS. Right now, we are developing a new set of protocols for the next phase of the GGCMI, which will focus on data quality, harmonization, model evaluation, and improvement.

Objectives

Build a lasting community of GGCM researchers that will collaborate to perform coordinated global and regional high-resolution impact assessment and model intercomparison studies to improve GGCM applications and our understanding of climate impacts on global food production and regional and temporal variations in these responses.

Membership

The GGCMI includes more than 20 modeling groups from 8 countries. We encourage new model groups to get involved in the project. For those groups that only have experience running models regionally, the project can provide the necessary data products and support to scale their existing frameworks up to global simulations.

Coordination

The GGCMI is being coordinated by a team from the University of Chicago and Argonne National Laboratory (ANL) Computation Institute, the NASA GISS Climate Impacts Group, and the Potsdam Institute for Climate Impacts Research. The coordination team will establish a consistent methodology, including simulation protocols and comparison metrics, for intercomparison and improvement of gridded model applications. Our protocol documentation is available here and continues to be updated.

Data and IT

The coordination team will also provide access to a database of assimilated gridded environmental, socio-economic, and climate datasets, as well as all outputs and analyses to enable individual and collaborative studies within the GGCMI network. The GGCMI leveraged an existing archive and IT infrastructure which was developed at ANL in order to facilitate data sharing and discovery for the 2012 fast-track. This resource, already serving 10 TBs of climate and impact model outputs for the AgMIP and ISI-MIP communities, will be updated and managed as an ongoing resource for the impacts community for years to come.

Access data: 

Timeline

The phase II project will span three years, with the first two years dedicated to model intercomparison, evaluation, and improvement. In the 3rd year, GGCMI participants will undertake a new global assessment of climate change vulnerabilities, impacts and adaptations.

Early results

GGCMI (global gridded crop model intercomparison) is a globally consistent, protocol-based, multimodel climate change assessment for major crops with explicit characterization of uncertainty. Results with multimodel agreement indicate strong negative effects from climate change, especially at higher levels of warming and at low latitudes where developing countries are concentrated. Models that include explicit nitrogen stress project more severe impacts. Uncertainties related to the representation of carbon dioxide, nitrogen, and high temperature effects demonstrated here show that further research is urgently needed to better understand effects of climate change on agricultural production and to devise targeted adaptation strategies. 

Median yield changes (%) for RCP8.5 (2070-2099 in comparison to 1980-2010) with CO2 effects over all 5 GCMs x 7 GGCMs (6 GGCMs for rice) for rainfed maize (35 ensemble members), wheat (35 ensemble members), rice (30 ensemble members), and soy (35 ensemble members).  Hatching indicates areas where more than 70% of the ensemble members agree on the directionality of the impact factor.  Gray areas indicate historical areas with little to no yield capacity.  The bottom 8 panels show the corresponding yield change patterns over all five GCMs x four GGCMs with nitrogen stress (20 ensemble members from EPIC, GEPIC, pDSSAT, and PEGASUS; except for rice which has 15) (Left); and 3 GGCMs without nitrogen stress (15 ensemble members from GAEZ-IMAGE, LPJ-GUESS, and LPJmL).  Reproduced from ELLIOTT, Et. Al. 2014

Median yield changes (%) for RCP8.5 (2070-2099 in comparison to 1980-2010) with CO2 effects over all 5 GCMs x 7 GGCMs (6 GGCMs for rice) for rainfed maize (35 ensemble members), wheat (35 ensemble members), rice (30 ensemble members), and soy (35 ensemble members).  Hatching indicates areas where more than 70% of the ensemble members agree on the directionality of the impact factor.  Gray areas indicate historical areas with little to no yield capacity.  The bottom 8 panels show the corresponding yield change patterns over all five GCMs x four GGCMs with nitrogen stress (20 ensemble members from EPIC, GEPIC, pDSSAT, and PEGASUS; except for rice which has 15) (Left); and 3 GGCMs without nitrogen stress (15 ensemble members from GAEZ-IMAGE, LPJ-GUESS, and LPJmL).  Reproduced from ELLIOTT, Et. Al. 2014

People: 

Current: Joshua Elliott | Ian Foster | Michael GlotterJames Chryssanthacopoulos

Recent Publications: