A new paper in American Journal of Geophysics, Geochemistry and Geosystems criticizes alarming projections of up to 2 meters in sea level rise due to increasing anthropogenic CO2 emissions - and implicitly media that acts as cheerleaders by foregoing critical thinking - because those claims are not based on data. 

Instead of noting that tide gauges with enough information to infer a trend don't show increased relative rate of rise, but instead show small positive negative and positive fluctuations, papers with claims of up to 2 meters in sea level rise are heavily promoted, including by groups who insist policy makers need to include those claims in flood maps. 

Albert Parker from the School of Engineering and Physical Science at James Cook University found data do not show increasing anthropogenic carbon dioxide emission has produced or will produce anywhere near that rise, even though relative sea rises and falls have been available since the 1800s, yet relative mean sea level rates of rise as computed by PSMSL haven't gone up meaningfully even using long-term data, such as those measurements that began before 1934. The oldest, most reliable mean sea level rates of rise have actually gone down -0.062 millimeters per year. 

Relative sea levels in San Francisco, data from PSMSL, plus GPS estimate of the land motion nearby the tide gauge location, for San Francisco, images from SONEL and JPL.

Given that data, a greenhouse gas abatement policy is not insurance against flooding, as claims suggest, because sea levels will rise nowhere near one meter much less two, at least not due to man-made climate emissions. It's too expensive and too important to allow satellite and GPS to replace the best data, the actual level of the sea using tide gauges. Tide gauges provide the largest dataset and more accurate data is better than less. The authors believe that using the least accurate information to create policy is a bad idea.

The authors write, "Even if some may have an interest to believe (and force the others to believe) the opposite, there is no alarming sea level rise driven by the anthropogenic carbon dioxide emission. Coastal management should not be based on extravagant claims having no real supporting evidence."