Sea Level Rise Is Worse Than Thought, New Research Shows

Sea levels are actually higher than thought because of a 
mismatch in research assumptions. Predictions for the
effects of sea levels due to climate change 
will need to be adjusted. 

Sea level rise, one of the most expensive symptoms of climate change might well be worse than feared, new research shows. 

The problem is that sea levels are already higher than we thought because of mistaken research assumptions. 

According to USA Today:

"The new research, published March 4, in the peer-reviewed British journal Nature, found that more than 90% of the existing sea-level studies use a reference sea level that is lower than the actual sea level along the coast. That means already dire projections about sea level rise might be underestimating the risk." 

Those studies underestimated baseline coastal water heights by an average of about a foot. Researchers studied hundreds of scientific studies and hazard assessments to arrive at this conclusion. The cause, according to the Associated Press, is a mismatch between the way sea and land altitudes are measured. 

Study co-author Philip Minderhoud, a hydrogeology professor at Wageningen University in the Netherlands, said a "methodological blind spot" between the different ways those two things are measured. 

Many studies assume sea levels without waves or currents, when the reality at the water's edge is of oceans constantly roiled bye wind, tides, currents, changing temperatures and things like El Nino, Minderhoud said, as the AP reported. 

 The AP continues:

"Adjusting to a more accurate coastal height baseline means that if seas rise by a little more than 3 feet - as some studies suggest will happen by the end of the century - waters could inundate up to 37%k more land and threaten 77 million to 132 million more people, the study said."

As you can see, this means mitigation plans for future sea level increases are obsolete before they're even needed. 

Some scientists say the study might be exaggerating the problem, but even so, this is just yet another complication as worsening effects of climate change loom. 

Also, more recent sea level studies are taking into account the discrepancy, so chances are future warnings about sea level rise will be more accurate.