While it has been long known that climate change is effecting sea level rise, it seems that the measurements haven’t been quite accurate over the last century, making recent corrections a cause for alarm.
There’s a good reason that “climate change” was previously referred to as “global warming,” because global temperatures are rising. Some have pointed to recent cold snaps as “proof” that global warming is a myth, but forget that these are canceled out by abnormally-high temperatures in other places. On the whole, the average temperature has risen by what may seem to be a miniscule 2.0 °F over pre-Industrial-Age temperatures. In reality, however, those two degrees are wreaking havoc in ecosystems around the globe.
Sea level rise is just one way that climate change scientists are measuring the effects. In the Arctic and Antarctic, as well as glaciers around the globe, ice locks up a significant portion of water. As temperatures rise, ice melts, and the sea level rises. Using sea level measurements, from as far back as 1901, a group of researchers at Harvard University came to the realization that old sea level alarms had been over-estimated. In other words, the sea level wasn’t rising as much as they had been estimating.
This seems like good news, until you figure in what the researchers discovered about the decades since 1990. Taking a look at measurements from 1901 through 1990, Harvard researchers estimated that sea level rise averaged 1.2 mm per year, lower than past estimates. Since 1990, however, sea level rise has been averaging 3 mm per year, a clear reflection of accelerated ice melt at the ice caps and in glaciers. Sea level rise is actually accelerating due to climate change.
Harvard researchers admit that the results are not definitive, and climate change scientists say further analysis will be necessary to get an exact measurement on 20th Century sea level rise.