On 23/07/2020 20:48, Norman Lynagh wrote:


I would be very wary about fitting trendlines to processes that are
likely to be highly non-linear and which may have step-changes.


I agree 110%. I have made this point on more than one occasion when the
same topic has been posted in the past. It is unscientific in the
extreme to fit arbitrary functions to a set of data and then use the
resulting parameters to extrapolate likely sea level way into the future.

I think everyone accepts that climate change will cause very significant
rises in sea level in the next eg 50-100 years but estimating the likely
extent is very tricky. The only approach I can see with any credibility
involves a proper combined climate and oceanographic model. (Which
clearly is being done at various academic institutions. Why not leave
this technically very challenging problem to the professionals?)