How Did Those UKCP Sea Level Projections Work Out?


By Paul Homewood

It’s time to check out some of those whacky projection made in 2009 in the UK Climate Projections, published by DEFRA with the help of the Met Office.

Today I’ll look at sea levels:

This was the headline projection:

The numbers are measured against the 1980-99 baseline, so the 2040 projection effectively equated to a rise of 3.6mm a year, increasing to 4.5mm till 2080.

There is little tide gauge data from the Thames estuary, but we can get a good idea of how this prediction panned out by looking at North Shields. As the land is sinking in the South East, the predicted rise at North Shields was slightly less, but the UKCP interface conveniently provides that projections at the latter as well:

The database confirms a projected rise at North Shields of 45mm between 2007 and 2021, 3.2mm a year.

However the actual data shows that sea levels have only risen by 13mm during that time. As the graph indicated, there is nothing unusual about either the 2007 or 2021 datapoints, and while sea levels can fluctuate up and down the overall trend is already well below the DEFRA projections.

Far from admitting their error and making their projections more realistic, DEFRA and the Met Office have doubled down on their nonsense, and are now predicting sea level rise of 600mm in London, in their central case:

Hilary Benn, who presented the 2009 report as Secretary of State at DEFRA, used it as a lever for wide reaching policy changes. Given that these changes have been premised on a highly flawed report, it is time that public policy is amended accordingly.