A Tale of Two Cities

I recently posted a chart of Los Angeles annual temperatures 1881-2011. Here it is again:

Los Angeles annual temperatures 1881-2011 GHCN via GISS

Looks like a fairly typical temperature chart - a warming trend into the 1930s, a dip in the 1940s, then a climb to a peak in the 1990s, followed by the un-typical dip to lower temperatures this century, the subject of that post. The data is GHCN (Global Historical Climatology Network) provided by the NOAA GISS website, and denoted as "unadjusted" which means no further adjustments by GISS. The GHCN data is most certainly adjusted however, as the following chart shows.

Los Angeles annual temperatures 1881-2011 GHCN vs Unadjusted (raw)

GHCN have lowered the raw data from 1881 to 1930 to produce a convincing upward trend. Note that the adjustment is progressively less, from a massive 1.9°C in 1881, smoothly to zero in 1930. There can be no justification for this "adjustment to fit an agenda", which is exactly what it is. Note the difference in the trend line slopes: from 0.08°C per century (raw), which is effectively zero trend, to 1.62°C per century. Instant global warming sans added heat. I've plotted data from the same sources for San Francisco:

San Francisco annual temperatures 1881-2011 GHCN vs Unadjusted (raw)

This is even more blatant jiggery-pokery, with a progressively increasing negative adjustment from zero for the present all the way back to 2.1°C in 1881. GHCN has turned a slightly negative (effectively zero) trend into a surprisingly (is it a surprise?) similar trend to that for Los Angeles of 1.62°C per century. The precise values are 0.016157 for LA and 0.016144 for San Francisco. Coincidence, perhaps, but I think not. I've seen some large GHCN adjustments, but the blatant fiddling here takes the prize.

As I said earlier, "instant global warming" without added heat. There are those who call sceptics "deniers". To those I say "explain or deny this if you can".

UPDATE 13th Feb 2011

I've just checked the GHCN data for both stations on the GISS site, and both have changed slightly since I downloaded the data on 7th Feb. I also had a dataset for SF from December last, and that's different too. Not just rewriting the past, but doing it regularly. I though only totalitarian regimes rewrote the past?

UPDATE 13th Feb 2011

Just a few minutes ago, I had displayed the GHCN temperature chart for Rochester, Minnesota, among others. With a dozen browser tabs open, I didn't realise that the chart was still displayed, so I reselected it from the GISS station selector, and displayed it again. Unbelievably, the data had changed by a few tenths of a degree (both for early and late years) within ten minutes! Some kind of official investigation is needed of this unjustifiable shenanigans.

Global Warming through the eyes of a True Believer

I was looking for something totally unrelated to global warming, climate change, blind meteorologists etc., when I stumbled upon "Golden State Heating Up, Study Finds" from 2007 on PhysOrg - not a site I've ever spent any time on in the past. I have seen a few links on Google News, but the brief summaries usually put me off - the site seems to be the haunt of dyed-in-the-wool believers in "settled science".

Average temperatures in California rose almost one degree Celsius (nearly two degrees Fahrenheit) during the second half of the 20th century, with urban areas blazing the way to warmer conditions, according to a new study by scientists at NASA and California State University, Los Angeles.

Of course, those who don't acknowledge the significance of the Urban Heat Island (UHI) effect wouldn't see the irony in that "urban areas blazing the way to warmer conditions".

The scientists found great variations in temperature patterns throughout the state. Average temperatures increased significantly in nearly 54 percent of the stations studied, with human-produced changes in land use seen as the most likely cause. The largest temperature increases were seen in the state's urban areas, led by Southern California and the San Francisco Bay area, particularly for minimum temperatures. Minimum temperatures at some agricultural sites showed increases comparable to some urban areas. Rural, non-agricultural regions warmed the least. The Central Valley warmed slowest, while coastal areas warmed faster, and the southeast desert warmed fastest.

Note "particularly for minimum temperatures" and "Rural, non-agricultural regions warmed the least" - the signature of UHI. No mention of that here, of course.

The paper (no title nor date mentioned - very useful) would seem to be LaDochy, S., R. Medina, W. Patzert (2007): Recent climate variability in California: Spatial and temporal variations in temperature trends, Climate Research CR 33:159–169. The trio seem to be unaware of UHI - in fact in their paper they say (thanks, CO2 Science)

"the small increases seen in rural stations can be an estimate of this general warming pattern over land," which implies that "larger increases," such as those found in areas of intensive urbanization, "must then be due to local or regional surface changes."

However, the thrust of this post is not directed at Medina et.al., but at the original NASA/JPL author of the article, for below my last quote from that is this graphic:

In Los Angeles, average annual temperatures have increased steadily over the past 130 years. Image credit: NASA/JPL/Cal State L.A.

Notice "increased steadily over the past 130 years". The author clearly is looking at the chart with the eyes of a "True Believer". He appears to be looking at the red trend line, not the (unsteady) blue running average, not the fact that temperatures after the 1997 peak dropped to lower than the late 1960s/early 1970s. The blue running average shows that clearly. The nearest I can get to that chart is this one from GISS, but it's very similar, except for the missing early 80s peaks.

Los Angeles annual temperatures 1881-2011 GHCN via GISS

The red running mean has dropped to the 1955/6 level, similar to that for 1976. Of course, if I were a "True Believer" I'd just not see that. Perhaps "True Believers" look at temperature graphs with a right tilt to the head, which always produces a "steady increase", and snowfall graphs with a tilt to the left, which produces a vague childhood memory of what snow looked like.