World Terrestrial Ecosystems use a combination of landform, land cover, and climate region information to objectively characterize ecosystem types. Using global climate models, land cover and climate region can be projected into the future. The latest global climate models, part of the 6th Coupled Model Intercomparison Program (CMIP6), use a variety of developmental and emissions scenarios called the Shared Socioeconomic Pathways, or SSPs. This layer shows the projected World Terrestrial Ecosystems in 2050 using SSP3-7.0, the scenario that assumes the atmosphere will nearly double its current CO2 levels by 2100. This amount of CO2 would raise the planet's average temperature 3.6 degrees Celsius by the end of the century. The Paris Agreement targets an increase of no more than 2.0 deg C.This layer can be directly compared to the 2015 World Terrestrial Ecosystems v2 and the projected World Terrestrial Ecosystems in 2050 for SSP3-7.0 and SSP5-8.5. Those layers and others can be found in the WTE 2015 to 2050 Comparison Project Layers and Maps ArcGIS Online Group. To learn more about this work, read our open access peer-reviewed journal article in Global Ecology and Conservation, Volume 57, January 2025, e03370: Potential 2050 distributions of World Terrestrial Ecosystems from projections of changes in World Climate Regions and Global Land Cover.MethodologyEcosystems are mapped by combining remotely-sensed and field methods. From remote sensing, data derived from satellites are combined with landforms derived from elevation, land cover derived from multi-sensor imagery, and climate variables modeled into annual averages and indicators. From the field, scientists find patterns and measurements which delineate regions that cannot be derived from imagery, most notably in differentiating savanna from dry tropical rain forests. The most subtle boundaries require ground truthing to identify tricky vegetation differences, especially when telling apart species of grasses in the tropics.CHELSA Climate DataGlobal climate models are quite coarse in resolution, so downscaling techniques often are applied to provide more detailed spatial resolution. CHELSA version 2.1 provides a set of downscaled (1-km) climate models from CMIP6. We obtained five different downscaled projections for 2041-2070 and three SSP scenarios (1-2.6, 3-7.0, and 5-8.5), along with a historical climatology for 1981-2010 The v2.1 data was accessed in May of 2023 from CHELSA's data download site (Karger, et. al., 2017). We classified the CHELSA models according to the climate region definitions in Sayre, et. al., 2020. This layer represents an ensemble of the five different models for SSP1-2.6.An older version of World Terrestrial Ecosystems 2015 used a different source for downscaled climate data (WorldClim version 2). CHELSA leverages more accurate downscaling techniques for both historical and projected climate information. References: Sayre, Roger, Karagülle, Deniz, Frye, Charlie, Boucher, Timothy, Wolff, Nicholas H., Breyer, Sean, Wright, Dawn, Martin, Madeline, Butler, Kevin, Van Graafeiland, Keith, Touval, Keith, Sotomayor, Leonardo , McGowan, Jennifer , Game, Edward T., Possingham, Hugh. 2020. An assessment of the representation of ecosystems in global protected areas using new maps of World Climate Regions and World Ecosystems. Global Ecology and Conservation, v21. DOI: 10.1016/j.gecco.2019.e00860.Karger, D.N., Conrad, O., Böhner, J., Kawohl, T., Kreft, H., Soria-Auza, R.W., Zimmermann, N.E., Linder, P., Kessler, M. 2017): Climatologies at high resolution for the Earth land surface areas. Scientific Data. 4 170122. https://doi.org/10.1038/sdata.2017.122.Land CoverWe obtained three Plant Functional Type-based SSP land cover models for the year 2050 and one for 2015 from: https://zenodo.org/records/4584775 on Jun 2, 2023. The SSP models were for 1-2.6, 3-7.0, and 5-8.5. The land cover model for this layer was the SSP1-2.6 model.References: Chen, G., Li, X. & Liu, X. Global land projection based on plant functional types with a 1-km resolution under socio-climatic scenarios. Sci Data 9, 125 (2022). https://doi.org/10.1038/s41597-022-01208-6.Chen, G., Li, X., & Liu, X. (2021). Future global land datasets with a 1-km resolution based on the SSP-RCP scenarios [Data set]. Zenodo. https://doi.org/10.5281/zenodo.4584775.World Ecological Facets (Hammond) Landform ClassesWe used the data from the image service in ArcGIS Living Atlas of the World.Reference: Karagulle, D., Frye, C., Sayre, R., Breyer, S., Aniello, P., Vaughan, R., & Wright, D. (2017). Modeling global Hammond landform regions from 250-m elevation data. Transactions in GIS, 21(5), 1040–1060. https://doi.org/10.1111/tgis.12265.

This application is for exploring the layers produced for the World Terrestrial Ecosystem (WTE) 2015 to 2050 Comparison Project. Those layers and others used in the models can be found in the WTE 2015 to 2050 Comparison Project Layers and Maps group or you can download the raster datasets in .tif format from DOI: 10.6084/m9.figshare.26078788. Suggest sequence of exploration. The default view is of the Change by Percent of Area for countries map. Click on any country to see how the land may be affected under each of the three CMIP6 scenarios we've modeled. Expand the Change by Percent of Area layer and turn off the countries and turn on the Hydro Basins layer. It's a very different picture when a more precise view of which lands could change. Explore the possible changes by scenario for the Hydro Basins. Turn off the Change by Percent of Area layer and turn on the WTE 2015 to 2050 Popup and WTE Types layers. Initially the 2015 Ecosystems will draw. Turn on one of the scenarios, let it draw, and then you can turn it on and off rapidly to see the changes. Zoom in and pan around the map while toggling the scenario layers. Click where you see great amounts of change to learn what type of changes may occur.Turn off the WTE Types layer and turn on the WTE Change Type layer. Each type of change is color coded - open the legend on the upper right to see what each color means and explore the map and scenario layers.To make the WTE layers, we used the Climate Regions data and Chen Land Cover layers. Explore these in the same way the as described in step 4 for the WTEs.For more about the SSP-RCPs read: Explainer: How ‘Shared Socioeconomic Pathways’ explore future climate change on Carbonbrief.com.References:To learn more about this work, read our open access peer-reviewed journal article in Global Ecology and Conservation, Volume 57, January 2025, e03370: Potential 2050 distributions of World Terrestrial Ecosystems from projections of changes in World Climate Regions and Global Land Cover.