An X-ray photoelectron spectroscopy (XPS) study was undertaken of the water/Cu(1 1 0)-system finding non-dissociative adsorption on clean Cu(1 1 0) at temperatures below 150 K. Thermally induced dissociation of D2O is observed to occur above 150 K, similar to the H2O/Ru(0 0 1) system, with an experimentally derived activation barrier of 0.53–0.56 eV which is very close in magnitude to the derived activation barrier for desorption of 0.50–0.53 eV. X-ray and electron induced damage to the water overlayer was quantified and used to rationalize the results of a recent XPS study of the water/Cu(1 1 0)-system where partial dissociation was observed already at 90 K.