a report from 1983 accepts a projection (on p. 2) of a 10 cm sea level rise over 25 years. And here is a journal article from 1987 which states (on p. 17):
Available estimates generally imply a rise on the order of one meter in the next century.
This is much less than one meter in 30 years. So clearly, while Agnew's statement may or may not be an accurate description of one particular research presentation about Norfolk, it does not represent the scientific consensus of the mid-1980s for global sea level rise projections.