Sea Level Is Rising – But So What?

By Julius Sanks

A good way to distinguish between a reasonable climate discussion and fearmongering is to examine the data. Fearmongering will contain incomplete data, or none at all. The person mongering fear expects us to take the claim on faith. But we don’t have to. Sometimes it is ridiculously easy to check the claim.

A case in point is a recent article titled “How map of Britain will change in next 80 years as towns and cities fall into the sea” [sic] by Sam Elliott-Gibbs. Note the headline emotionally and deceptively implies they will “fall,” but the text goes on to discuss sea level rise based on air temperature. The article cites Climate Central to claim large areas of England will be under water by the year 2100. The only evidence provided is a couple of maps built on Climate Central’s interactive mapping tool. Climate Central uses topographic data to forecast flooding based on sea level and blames sea level rise on climate change.

Climate Central bases its sea rise forecast on material that is mostly speculative. It cites the IPCC and a NOAA report. The NOAA report is actually a group effort involving several government agencies, none of which, except NASA, are directly involved in atmospheric science. The NOAA contribution comes from the National Ocean Service, not the atmospheric side. These sources extrapolate sea level rise from 2020 into the future.

But sea level change is something we can check and compare with Climate Central’s claims. We have used radar aboard satellites to measure sea level quite accurately since 1992, when the TOPEX/POSEIDON satellite was launched. That was the first time we could collect worldwide data. All earlier information is based on point, not worldwide, sources.

According to Climate Central, Peterborough, England will be on the coast in the year 2100. The town is 8 meters above current sea level, so that is how much the ocean must rise. Will it?

Climate Central claims the red area will be under water in 2100. 80 years of ocean rise? Probably not. Source: Climate Central.

According to NOAA’s Laboratory for Satellite Altimetry — unsurprisingly, not one of Climate Central’s sources — sea level rise is quite linear. The actual rate is 3.1 ± 0.4 millimeters per year. At that rate, it would take 2,580 years for the ocean to reach Peterborough. The ocean would have to rise 100 millimeters per year — more than 30 times faster than it actually does — to soak the town in 2100. It is worth noting the NOAA report does not predict anything near an 8-meter rise in 80 years. Its worst, and therefore least likely, case is 1 to 2 meters.

30 years of actual sea level rise. The colored bars indicate service lives of four satellites used to get the data. JASON-3 remains operational. Source: Laboratory for Satellite Altimetry.

Climate Central needs more than a fancy interactive map to make a convincing case sea level will change that drastically.

Julius Sanks is an engineer with experience developing weather satellites and weather forecasting systems for the US Air Force and NOAA.

via Watts Up With That?

December 3, 2022

Sea Level Is Rising – But So What? — Watts Up With That?