In one spot, Sweden’s coastline has risen about 300m since the last ice age ended 10,000 years ago.
The falling water level puzzled people for generations. Some Christians believed it was caused by still-receding waters after the Biblical story of Noah who built an Ark to rescue the world’s animals from a flood sent by God.
Elsewhere in the world, many nations are worried by the potential costs if sea levels rise in line with scenarios proposed by a UN panel of climate scientists for a gain of 18cm to 59cm this century, after rises of 17cm last century.
The panel says that rising temperatures, caused by emissions of carbon dioxide from burning fossil fuels, are the cause.
The UN’s projection excludes the possibility of an acceleration in the melt of Greenland and Antarctica, because that is uncertain.
Even so, many experts expect a quickening thaw and say that sea levels could rise in total by a meter this century.
Almost 200 governments are meeting in Doha, Qatar, this week to try to revive a UN-led effort to slow climate change that is also projected to cause more floods, droughts, heatwaves and more powerful storms.
Professor David Vaughan, of the British Antarctic Survey, said sea levels will change at widely differing rates due to land uplift or subsidence, shifts in gravity and variations in ocean currents and winds such as in the Pacific Ocean.
Sea levels near Greenland, for instance, could fall because its ice sheet has a strong gravitational pull that raises the local sea level. If the ice thaws, the water level will sink.
“Scandinavia will be emerging ... sea levels around Antarctica and Greenland will be going down. Almost every projection I have seen shows the highest rates of rise will be in the equatorial Pacific,” Vaughan said.
Near Lulea, local resident Hans Lindberg, 56, looks out of the wooden seaside cabin that his parents built in 1960 toward what was then the island of Kalkholmen a few hundred meters away.
“We could look out from here and only see the sea,” he said, pointing to a muddy bank where reeds are growing and linking the island to the mainland. Residents of the former island say they fear the link may bring unwanted visitors — perhaps burglars.
“You can walk to the island now. When I was young my father had a heavy boat that we could pull through the shallow part of the channel. That’s now impossible,” he said.
As evidence of the change, he shows a faded album with a black-and-white photograph of two young girls — his sister and cousin — playing in a sandpit in the 1960s by the cabin. It shows an open sea with no sign of the muddy causeway.
It was the 18th century Swedish scientist Anders Celsius, after whom the temperature scale is named, who first estimated the rate of land rise by studying 16th century property documents that marked offshore rocks, valued by hunters, on which seals basked.
By Celsius’ time, many of the “seal rocks” were so high out of the water that the mammals could no longer climb onto them, according to a book by historian Martin Ekman. With the data, Celsius was the first to come up with a rough estimate of the sea’s fall — a slight overestimate of 1.4cm a year.
Aware that rising global seas will reduce the local land rise, Lena Bengten at Lulea municipality says rules due to take effect this year will ban new homes less than 2m above sea level after a recent building surge.