One of the most common arguments climate alarmists make is that the rate of sea-level rise is “accelerating” or rising faster every year.
Sea-level data reported from satellites indicate seas are rising approximately of 3.3 mm/year (See Figure 1). By contrast, tidal stations have recorded a rise of approximately 1 to 2 mm annually, a rate which is little changed over the century or so for which we have adequate records. Indeed, as reported in Climate at a Glance: Sea Level Rise, the oldest tide gauge in the USA, in New York City, shows no acceleration at all going back to 1850.
Why the large difference?
The answer it turns out is simple. When NASA and NOAA launched new satellites, the data they produced wasn’t the same as the data recorded by earlier satellites.
Figure 1. University of Colorado sea level data, showing the trend and acceleration. Note that the graph shows no overlap between the individual satellite records. SOURCE: UCSLR Group
Citizen scientist Willis Eschenbach obtained NOAA’s Excel spreadsheet showing the full dataset for each of the four satellites. He plotted the NOAA data. Unlike the Colorado data above, it included the full overlap between the individual satellites. He then looked at the rate of sea-level rise shown by each of the four satellites separately. Figure 2 shows that result.
Figure 2. NOAA sea level data, showing the trend of each of the full individual satellite records and the overall trend. SOURCE: NOAA Excel Spreadsheet
The two most recent satellites record significantly higher rates of sea-level rise than the earlier two satellites. The first two satellites agree quite well, but they both show a much smaller trend than the latter two satellites. Neither set of the satellite record shows any accelerating trend. The UC scientists simply combined the two dissimilar data sets, plotted a new trend showing acceleration, and didn’t mention the difference.
See the complete analysis here.
This is either incompetent or dishonest, and certainly not up to even the simplest of basic science principles. Virtually any high school or college student who presented such work for a class would get called out on it by their instructor for showing a false trend.
This could explain why former President Barack Obama and Bill Gates felt secure when they each bought ocean front property. They proclaim loudly that seas are rising dangerously, but like the many of climate alarmists, their actions belie their words because they know the data is badly flawed. The data shows seas are not rising at an accelerated rate.