So, in order to gin up some panic about global warming during a very cold and snowy winter, the New York City Panel on Climate Change issued a report saying that sea level might rise 6′ in the next 85 years.(1). Now, of course it *might* happen – anything that is not logically impossible *might* happen. In fact, it is fervently to be hoped that, as the climate changes (and it always does!) the sea level rises rather than falls. If – almost certainly when – the ice sheets return, as they have many times in the last 3.5 million years, a 6′ rise in sea level will look like a minor inconvenience by comparison. On the plus side, if the ice sheets return, those folks worried about Quebecois independence or preserving the Taiga forests could stop, as Canada and the Taiga would then be under several miles of ice.
Of course, melting the ice caps seems to take many thousands of years. And the evidence suggests that the ice caps have endured centuries at a stretch of temperatures as high and higher than they are now – and they’re still there. So, there’s that counterpoint if panic isn’t your cup of tea.
A 6′ rise? So, the Statue of Liberty is about 8′ tall, including the base? Let’s check in with the Oracle Wikipedia:
Sooo – looks like the water level in the picture is up maybe 250′? *Slightly* more than 6′. If all the icecaps in the north and south melted, then, yea, 250′ is not out of the question. But nobody even a little sane is suggesting anything like that. Last I checked. I hope.
Of course, to get even a 6′ rise, you’d still need some combination of much warmer (expanding) water and significant ice sheet melt. This *might* happen. What one wants to know is: how likely is it to happen?
From what we know or can reasonably entertain, the chances are small. Very small. So small you’d be better off worrying about asteroids, gigantic volcanoes and huge earthquakes – other events that also happen from time to time, and have caused incredible amounts of damage.
How unlikely? First up, based on the best recent studies of ancient temperatures, in the last 11,500 years since the current interglacial period started, temperatures were as warm or warmer than they are now about 25% of the time – almost 3,000 years! But the ice caps didn’t melt. So we’d need much warmer temperatures, much lager time frames than 85 years, or both, before melting icecaps become likely.
Which brings us to point two: the temperature hasn’t increase in the last 18 or so years.(2) What if that trend is *the* trend for a while? Perhaps, over the next 85 years, temperature don’t materially change, or go up only slightly. Then the sea level changes not at all or only slightly. Astrophysicists studying the Sun’s output think this might come about. At any rate, we can look at a trend than runs from, say, 1970 to 1998, and figure temperatures are going to continue to increase rapidly, or we can look at a trend that runs from 1998 to 2015 and conclude temperatures are not changing at all within the sensitivity of our instruments to detect such change. Or some other span, with some other trend – me, I like the ‘since the current interglacial began’ span, or, better, ‘since the current ice age began’ – 11,500 years and 3.5 million years, respectively. In those spans, temperatures go up, down and all around, despite human beings making no contribution to atmospheric CO2 during the vast bulk of those times.
Third, despite the bath Lady Liberty is taking in the picture, 6′ is the outlying extreme – that’s if all the variables in the models (models that have consistently failed to predict anything – always keep that in mind) fell toward the worst case end of things. But, so far, for 20 years running, the measured temperature has fallen at or below the low or presumed best case predictions – no hockey stick. So, even going with the hopelessly flawed (as in: wrong) models currently used, the chance is slight.
But, boy, is that picture scary. I think they should have gone all in, and used this picture:
It’s only slightly less realistic than the one they did use.
1. They add ‘in New York’ to the claim, which makes sense for a report put out by a group with New York City in its name until you think about it. New York, as opposed to anyplace else? It would require some ‘splainin’ (a) to say why New York gets a different rise in sea level than, say, Tierra del Feugo. In marketing, we talk sometimes about bringing the message home – sea level might increase 6′ in Tierra del Fuego as well, but since your average reader could be easily convinced those exotic lands abut the Islets of Langerhans by the proper application of furrowed brows and stentorian diction, we’ll let it slide.
a. I here footnote a footnote: of course, there are differences in sea level from place to place, and differences in sea level change – the crust, until only recently weighed down by unimaginably massive ice sheets, is still bouncing back in some places – and dropping in others. And expansion caused by unequal warming, and so on and so forth.
2. Saying, as was trumpeted earlier this year, that 2014 was the warmest year ever based on a .02 degree imputed change which seems to have had to do with warmer lows, not warmer highs – well, that’s not ‘warmer’ in any material sense. It might even be cooler, given the nature of the interpolations and other fudging, not to mention that .02 degrees is a lot more accuracy than the instruments permit. It’s an estimate, folks, based on assumptions and subject to a high likelihood of error.