These scenarios are an update of the NW4/WB21 scenarios originating from 1997/2000. The update incorporates in the WB21 scenarios the results of the recently published IPCC Third Assessment Report (TAR). Together with the previous versions, these scenarios had been the standard for climate impact studies in the Netherlands from 1997 onward. They are replaced by new ones in 2006, after the publication of the IPCC Fourth Assessment Report (4AR)