We are obliged by the proposed new Canadian laws against spreading climate disinformation on the internet to tell you that this graph is upward sloping. And that Alaska is one of those states that, being near the Arctic, is especially hard hit by climate change along with all the others. So its sea levels must be rising rapidly. And as you can see, they are. From 1980 to the present the sea surface at Juneau has risen by nearly 15.5 mm per year. And to make it even scarier, it’s rising down, because “nearly” in this case is a euphemism for “minus”. Where will it all end?
Well, at CDN we like to calculate how long it would take for the sea to go up by one meter in the various spots on our “CDN by the sea” tour at whatever rate it is currently rising there. And in Juneau the answer is just minus 65 years, plus however long it takes to build a time machine that can run backwards. So if you plan to go to the water’s edge in Juneau, you probably won’t want flip flops because it’s not all that warm, and anyway a good pair of running shoes might come in handier.
During the last glaciation, a couple of miles of ice accumulated on the upper half of the North American tectonic plate. All that weight pushed the continent down some metres into the mantle in the north, while lifting the continent up at the south end. This downward slope to the north is why much of the liquid fossil fuel that was contained in the earth's crust along the eastern side of the mountain range flowed north and collected in Alberta's oilsands. This is why the earth is not spherical without the polar ice; it is fatter at the equator than around the poles because of the weight of the ice.
Anyway, when much of the ice melted circa 12,000 years ago, the continent began to spring back into a more level position. It is still in the process of bouncing back. So what looks like sea levels falling in the north is really mostly a rising of the landmass as the tectonic plate alters its tilt slightly. Same thing can be observed in Europe, where ocean water around Denmark is receding and the sea level around Spain's Mediteranean appears to be rising.
Critical commentators should not humour the climate alarmists by playing their game of measuring "sea level rise." That's not really what is happening, even when changes can be measured.
What do the numbers on the Alaska sea graph represent?