Downloading CMIP5/6 Models Datasets from ESGF in a Nutshell
This tutorial is applicable to downloading both CMIP5 and CMIP6 model output, and will cover on downloading from Earth System Grid Federation (ESGF).
This is aimed to serve as a quick guide to download global model output. For any other questions, please see the detailed ESGF guide, or reach out to fellow folks working with CMIP output (at UIUC or the developers at LLNL). Please take any suggestions provided in this guide as a grain of salt.
Workflow of Dowloading CMIP model datasets from ESGF nodes

Login to ESGF-LLNL Node.
CMIP5: https://esgf-node.llnl.gov/search/cmip5/
CMIP6: https://esgf-node.llnl.gov/search/cmip6/
Identify and Apply Search Conditions
Identify Best-suited Download Method
Proceed Download to Keeling