Saturday, 12 November 2016

NASA scientist makes a booboo

Back in 2012, when so-called "Superstorm" Sandy was current news, there were lots of dire predictions of "What is to come". At the time, I bookmarked several newspaper, blog, and other articles. While I was sorting out my links, discarding purely alarmist, inaccurate, and dead pages, I came across this one, and spotted something significant I'd missed at the time. Titled "Superstorm Sandy and Sea Level Rise", an interview with Cynthia Rosenzweig, "a climate impacts expert at NASA Goddard Institute for Space Studies, co-chair of the New York City Panel on Climate Change, and director of the NOAA-sponsored Consortium for Climate Risk in the Urban Northeast.". Wow - she must really know her stuff? She certainly appears to, here's her response to the question 
What kind of sea level rise has New York Harbor seen over the past century?We’ve had roughly a foot of sea level rise in the New York City area in the past century. That’s measured at a tidal gauge near Battery Park just off the southern tip of Manhattan.
The majority of the sea level rise in the New York City region is due to global warming: primarily, because of thermal expansion of ocean water as it warms and secondly, melting of land-based ice sheets.
Land subsidence [sinking] in the New York City area has been roughly 3-4 inches per century, which is primarily due to the Earth’s crust rebounding* from being compressed by massive ice sheets that covered Canada and the northern U.S. about 20,000 years ago near the end of the last Ice Age. Local variations in ocean surface elevation associated with the strength of the Gulf Stream has played a small role as well.
That's fine, but later
How does sea level rise in New York Harbor compare to other parts of the U.S.? What about the global average? Sea level isn’t rising evenly throughout the world. On average, global sea level has risen about eight inches since 1880. So, the New York rate of sea level rise of nearly one foot is higher than the global average rate.
Just a cotton-picking moment, she said that land subsidence in the New York City area was 3 to 4 inches over the last century. That makes true sea-level rise at New York 8 to 9 inches, compared with the global rate of 8 inches since 1880. There was very little if any rise anywhere in the world between 1880 and 1912, a hundred years back from when this article was written. 12 inches is certainly much higher than the 8 for global, but the true comparison is between 8-9 inches and 8 inches. I hope this was a simple mistake. For now, I'll give her the benefit of the doubt.

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