UNDERSTANDING CMIP6 DATA

The statistics here are derived from observed trends in historical data combined with climate models used to predict future conditions. Most future climate simulations are on a much wider scale, which can make accurate understanding of local climate very difficult. The base data from NASA addresses these problems by drawing from thirty-five different climate projections, downscaled to a much higher resolution.

Observed climate data is sourced from Global Meteorological Forcing
Dataset (GMFD) for Land Surface Modeling, a dataset available at high resolution from the Terrestrial Hydrology Research Group at Princeton University.  More details about the original data can be found in the tech note.

Like any projection, this dataset does not come with a guarantee of accuracy and is subject to change depending on future events and the decisions we make about our climate future. However, the authors of the dataset have taken multiple steps to ensure it is as close to accurate as possible. Outcomes have been calculated for four possible climate scenarios based on the actions we take in curbing carbon emissions in the future (moderating emissions, middle of the road, high emissions, and accelerating emissions).  Data is also sourced from multiple models.

For this subset of the data, the daily averages have been compressed into seasonal and annual projections. Annual projections from eight different models have been aggregated into a set of smoothed projections, which will likely be the most accurate of the datasets available.

Each dataset includes projections for twenty-six climate variables such as temperature, wind speed, growing season length, and precipitation, with this data available at different scales. The raw data shows daily calculations for each of the models and climate scenarios. The annual projections show annual calculations for each of the eight climate models individually. The smoothed projections show annual calculations aggregated from all those models, also showing a margin of error for these numbers.

Calculations cover all years from 1950-2100.

You can download the data simply by accessing the download page and clicking the name of the file you need.  To access the files, right-click on the zipped file folder and choose “extract all.” This will give you access to both the Excel spreadsheet of climate projection data and a PDF with information on the dataset and graphs for each of the calculated variables.

Applications

NASA’s stated purpose for CMIP6 data is:

“to assist the science community in conducting studies of climate change impacts at local to regional scales, and to enhance public understanding of possible future climate patterns and climate impacts at the scale of individual cities, communities, and watersheds.”

This subset of the data has been tailored to the needs of Tribal communities, with statistics chosen in collaboration with stakeholders.  Variables such as growing degree days, day of first frost, and length of the growing season are intended to be especially useful for agricultural professionals and those working on food sovereignty initiatives.  Data on heat hazards can inform individuals about the level of risk in their communities and enable the development of appropriate mitigation strategies.

Finding appropriate ways to communicate this data is important. The graphs provided by Native Climate are one way of sharing this, but other interpretations such as maps or visual presentation of climate impacts can enhance understanding of the material. We also want to encourage alternative and innovative interpretations of this data.

Through our “All Climate is Local” project, students from Tribal Colleges and Universities were given the opportunity to research and create stories in any medium about climate impacts in their communities and show examples of how they are adapting to these challenges. You can view their projects at the link below – or fill out our climate story form to tell us a story of your own.

• View “All Climate is Local” projects
• Share a climate story via our story submission form

All the datasets provided here are open-access and Native Climate encourages sharing and new interpretations of the data.  When citing this dataset, please credit both Native Climate and the underlying dataset with the references provided below:

Native Climate. (2024). CMIP6 Agricultural Climate Projections. Montana Climate Office, University of Montana.

Thrasher, B., Wang, W., Michaelis, A. et al. NASA Global Daily Downscaled Projections, CMIP6. Sci Data 9, 262 (2022). https://doi.org/10.1038/s41597-022-01393-4

Thrasher, B., Wang, W., Michaelis, A. Nemani, R. (2021). NEX-GDDP-CMIP6. NASA Center for Climate Simulation. https://doi.org/10.7917/OFSG3345