From about 1993 to 2010,
off the West Coast of the United States, we've seen about zero sea level rise or even negative sea level rise,
so sea level was falling during that time period,
but since about 2010, 2011, we've seen this really rapid increase
in sea level off the U.S. West Coast.
We’re seeing this recovery back towards the global mean,
and if this continues to increase, then you would expect to start to see sea level impacts
associated with this increase, increased coastal erosion,
increased high-tide flooding, these kinds of things as sea level continues to increase.
Sea level rise is caused by climate change.
So there's a number of things happening. One is there's this background increase in sea level associated
with global warming, so thermal expansion and the melting of ice, which is
impacting sea level along the West Coast. That's causing this long-term increase.
Natural Climate Cycles
But on top of that increase, there’s this oscillation that occurs. Actually a number of oscillations.
So the Pacific Decadal Oscillation is one of those. The El Nino-Southern
Oscillation is another. The Pacific Decadal Oscillation is
a large-scale climate signal centered in the Pacific Ocean. Every 10 years,
we see this shift in the sea level between what we see in the Western Pacific
and what we see in the Eastern Pacific. And these oscillations suppress
or elevate sea level over different time periods, and really either exacerbate
or diminish the effects of that long-term sea level.
Since about 2010, 2011, we’ve been seeing this
shift in that decadal variability associated with the Pacific Decadal Oscillation,
and what that’s doing is casing sea level along the West Coast of the U.S.
to go up. Since 2015, sea level has risen on the West Coast bu almost one centimeter per year
The global average is 3.3 millimeters.
So really high rates of sea level, causing sea level to shift very dramatically, and this increase that we’ve been seeing
in the satellite records, and also in some of the tide gauge records along the U.S. coast,
as well. Why It Matters
Trying to get a clear understanding of how sea level’s going to change and how it’s going to change, I think,
is really important so we can inform people and they can make good decisions for their future
and we can start to adapt and adjust our way of living
in order to account for these effects that are going to occur in the future.