Which buffer type accounts for the curvature of the earth and is used at large regional or global scales?

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Distances on the Earth’s surface must follow its curvature to be accurate at larger scales. A geodesic buffer uses geodesic distance along the ellipsoid or sphere, so the boundary is true to how distance actually accumulates on the globe. This makes geodesic buffers appropriate for regional or global analyses, where planar (Euclidean) distance computations would distort shapes and sizes. Euclidean buffers are based on a flat plane and work well only in small areas or when a suitable projected coordinate system minimizes distortion. Polygon overlay is a different operation that combines or intersects polygons, not a method for creating distance-based buffers. Vector distance measurement describes how distance is calculated rather than the method used to create a surrounding area. So the option that accounts for Earth’s curvature and is suitable for large-scale work is the geodesic buffer.