Ecological zoning for climate policy and global change studies

As climate change accelerates, nations are moving towards meeting their nationally determined contributions and reducing greenhouse gas (GHG) emissions. Reporting of this from the agriculture, forestry and other land use sector relies on data related to land use and management, climate and soil type. Where such data are unavailable, the Intergovernmental Panel on Climate Change (IPCC) provides a set of default factors, based on an extensive literature review of likely GHG emission factors and carbon stock changes disaggregated by the Food and Agriculture Organization’s global ecological zones. As understanding of global ecological zones under environmental change improves, it becomes necessary to reassess such ecological zoning approaches to enable reporting of GHG emissions to support nationally determined contributions and global change studies. Here we propose a globally consistent ecological zoning approach based on Holdridge life zones using climatic data from the Climate Research Unit on a 0.5° grid, which tackles certain limitations found in the existing guidance provided by the IPCC. A set of three global ecological zone maps based on Holdridge life zones were devised using increasing levels of aggregation, which could support sustainability studies of global environmental change, specifically climate change, and be used as a zoning approach by the IPCC.