On many occasions Mr. Cina has asserted that I have claimed that an increase in temperature of just 3ºC will cause sea level to rise by 400 feet. There is a nugget of truth in this, but he, as usual, misrepresents the reality.
Here’s what I wrote on May 10, 2013:
"if we were to stop emitting all CO2 right now, and never emitted any more CO2, then, when all the dust had settled, the earth would be in pretty much the same state it was in 3 million years ago: average surface temperatures about 6ºF hotter than they are today, and sea levels between 16 and 131 feet higher than they are today.”
Not the same thing as 400 feet for a 3ºC rise, is it? So where did Mr. Cina get his numbers? I honestly don’t know. I have searched through the entire website for any such statement, and found none. Check it out for yourself: go to LiveScience.com and use their search function to search for
Crawford “400 feet”
I got four hits — every one of which is one of Mr. Cina’s accusations. There’s no statement from me to that effect. This may be the statement that Mr. Cina is twisting:
"The page you quote describes the situation hundreds of millions of years ago. Yes, there was more CO2 in the atmosphere then -- and the earth was a LOT hotter then and sea levels were some 400 feet higher than they are today. “
On June 5th, 2015, I wrote this:
"As you can see from the graph, the correlation between CO2 concentrations, global mean temperatures, and sea level is quite close. Very roughly speaking, a change in CO2 concentrations of 100 ppm led to a change in global mean temperatures of 4ºC and a change in sea level of nearly 400 feet.
Please note that these are on the negative side of the relationship, and these are equilibrium values, not immediate values."
Once again, Mr. Cina is shown to be a liar.
And what does the science say?
In past times, sea levels have been much higher than they are today. Here’s one source showing that sea levels were 400 METERS (that’s about 1300 feet!) higher than they are today. Indeed, the graph clearly shows that, for most of earth’s history, sea levels have been at least 100 meters (300 feet) higher than they are today. If the polar caps melt, sea levels will surely be hundreds of feet higher.
The catch here is that, even with strong global warming, the ice caps will take thousands of years to melt. Current thinking is that global warming will cause sea levels to rise by only a few feet before the year 2100, but growing evidence suggests that this may be too optimistic.
Followup:
This is really funny: I had ignored Mr. Cina's blatant lie about sea levels for months, but when I finally demanded that he support his claim with an actual citation, he came back with this:
"Did you write that 3ºC of warming caused by AGW "would still mean a planet with sea levels several hundred feet higher”?"
Now ‘400 feet’ has suddenly been changed to ’several hundred feet’. He didn’t blink an eye about changing his story. This guy truly is a shameless liar.
By the way, here’s a graph of actual sea level rise:
