I have created a geometry in a solid modeller but the scale used is wrong. Is it possible to scale the geometry in ABAQUS?

Yes it is possible to scale the Geometry when it is read into the CAE program. Select the appropriate input using File --> Import --> Part
Change the File type to the appropriate depending on the format. Select the file and click on OK. In the form that pops up click on the Scale TAB and set the toggle key for Multiply all lengths and enter an appropriate scale factor value.