Land Use is shorthand for Land Use, Land-Use Change and Forestry (LULUCF). The sector is both a source and sink of greenhouse gases. LULUCF is subject to fluctuations and revisions as methodologies change. What is Mt CO₂-e? Emissions are a combination of gases. Most are Carbon Dioxide (CO₂). The other gases are measured as a Carbon Dioxide equivalent (CO₂-e) based on the amount of heat they trap in the atmosphere. They’re measured in Million Tonnes (Mt).