Much ado has been written about the accelerating melting of glaciers and sea ice, and how rising sea levels will submerge coastal cities. A study by the University of York found evidence for a period of enhanced pre-industrial sea-level rise of about 2-3 millimetres per year in three locations — Nova Scotia, Maine and Connecticut, which were largely natural, without any human constructions or man-made factors. In other words, sea levels have been slowly rising at a fairly continuous since the Little Ice Age without human influence.
Just a bit of a side note: The Little Ice Age lasted from 1300-1850. There were two phases of the Little Ice Age, the first beginning around 1290 and continuing until the late 1400s. There was a slightly warmer period in the 1500s, after which the climate deteriorated substantially, with the coldest period between 1645 and 1715. During the coldest phase of the Little Ice Age, average winter temperatures in Europe and North America were as much as 2°C lower than at present. So, warming since 1715.
At issue were studies that suggested rising sea levels were accelerating, implicating human caused climate warming. This was based on evidence collected in the noted northern east coast areas — Nova Scotia, Maine and Connecticut. Previous studies showed that, since the 1950s, rates of sea level rise along the Atlantic coast of North America were faster than the global average, leading to this region coming to be known as a sea level rise “hotspot.”
The new study speculates that observed variations (i.e. observed greater than average change) are consistent with sea‐level “fingerprints” of Arctic ice melt, and that sea‐level fluctuations are related to changes in Arctic land‐ice mass.
Lead author Prof Roland Gehrels, from the University of York’s Department of Environment and Geography, said this earlier rapid episode of sea level rise in the 18th Century (coinciding with the warming post-1715) wasn’t known before. To find out what the warming is doing to sea levels today, the team examined the base level from historical times:
“In the 20th Century, we see rates of up to three or four millimetres per year, faster than in any century in at least the last 3000 years. In the 18th Century they were slightly slower, but still much quicker than you would expect for the Little Ice Age, partly because the Arctic was relatively warm during the 18th Century. ”
“It was a pre-industrial phenomenon, so there were no anthropogenic forces – or human influences … In the 20th Century they might have played a key role but well before industrialization, those rapid episodes of sea level rise on the north east coast of North America in the 18th Century might have been due to natural causes.”
The only clarification I would add is in the last sentence of the two paragraph quote, where Prof Gehrels says “might have been due to natural causes.” Clearly, the timing of the variations were pre-industrial, and had to have been due to natural causes.
So, yes, the climate is changing. No, the evidence does not support that the change is human-caused.