Countries need to provide clarity on the role of carbon dioxide removal in their climate pledges - William F Lamb; Carl-Friedrich Schleussner; Giacomo Grassi; Stephen M Smith; Matthew J Gidden; Oliver Geden; Artur Runge-Metzger; Naomi E Vaughan; Gregory Nemet; Injy Johnstone; Ingrid Schulte; Jan C Minx (Environmental Research Letters)