The graph below shows the difference between USHCN average maximum and average minimum temperature since 1930. The gap is getting smaller due to UHI effects keeping nighttime temperatures up.
Alarmists claim that this is due to increased humidity caused by global warming, but as usual they have no idea what they are talking about.
Average long-term trends (1930 – 2010) indicate that temperature has warmed, but little change has occurred in dewpoint and specific humidity.
USHCN says that they make a 0.1F UHI adjustment, which is about 1500% too small.
Neither you nor those at the Hockey Schtick seem to be able to write a headline that matches what the research found. This from the abstract:
“Trends since 1947 indicate that the warming of temperatures has coincided with increases in dew points and a moistening of specific humidity. This moistening is especially pronounced during the summer in the Midwest. Nationally, trends in relative humidity show little change for the period 1947 – 2010 during which these data are more homogeneous. However, moistening has occurred throughout the central U.S. while other regions have seen drying. Urban-related warming and drying trends are present in the data but their effect is minimal. Regional changes in landuse and moisture availability are likely influencing trends in atmospheric moisture.”
Your 1.5 degrees UHI headline is one more step toward science fiction site of the year.
RGates
you’d understand science fiction, wouldn’t you.
R. Gates
What was your point is pasting that paragraph? Explain please.
Abstract says: “Urban-related warming and drying trends are present in the data but their effect is minimal.”
Steve’s headline says: “1.5 Degrees UHI Since 1930”
1.5. degrees would be far from minimal.
Gates. get a brain. The authors were referring to the “effect” on their humidity measurements.I hope you aren’t as dense as you pretend to be.
“Nationally, trends in relative humidity show little change for the period 1947 – 2010”
The temperature comparison is for the whole country. Do you know what the word “nationally” means?
Apparently he does not. And it’s just another mistake in a long list of mistakes that his ilk continually makes.
They are their own worst enemy. That they continually show how incompetent they are harms them because it shows everyone they don’t know what they are doing and thus there is no reason for anyone to be worried about “global warming”.
Using new propaganda to verify past propaganda. Not exactly the scientific method.
UHI is not a constant, the level depends on the time of day and weather conditions. I have seen differences of 4 degrees C after sunset on a winter day. Think what a hot summer day will do for those poor buggers in the city. A lot of those believing in warming live in cities, no wonder they feel the heat.
I am so glad to see this issue finally getting the attention it deserves. I have been telling folks for over 25 years that UHI is corrupting the data. UHI does not depend upon large cities, it just needs infrastructure, and therefore it is not restricted to cities. Stations in the midwest that have not had infrastucture changes (UHI) around them show zero warming over the past century.
Only a cidiot (someone who actually prefers living in big cities) would not understand the warming effect of UHI at night. But then, there is that mental disorder from which about half the population suffers.