The Italian Job

Though warming alarmists usually ignore it, temperature data that appear to show warming since the mid-20th century is skewed by the "urban heat island" effect. Given the increasing spread of cities, this is a particular problem in the U.S., but "I['ve] assume[d] European measurements are similarly flawed."

One European weather station is WMO Identifier 16239, located at the Ciampino airport outside Rome, at 41.78 degrees North Latitude, 12.58 degrees East Longitude. I glanced at the maximum recorded temperatures (available at the European Climate Assessment website for years between 1951 and 2005), which appeared to show a warming trend. Is this climate change or something else?

Based on the photographic evidence from Anthony Watts' Watts Up With That? via information from Paolo Mezzasalma, I'd say the latter:

While there are significant and systemic problems with USHCN stations in the United States, there are also problems with stations worldwide. One of the problems is that a good percentage of GHCN stations are at airports. For example, Paolo sent along a photo of the weather station at the Ciampino Airport in Rome, Italy. It piqued my interest for obvious reasons.


source: Paolo Mezzasalma via WUWT?

Two words might characterize the culprit: "jet blast." If that isn't enough, to the North on the opposite side of the runway, there's also a parking lot. Meaning the Ciampino facility is positioned between two large expanses of asphalt--as Anthony Watts says:

caught between two modes of transportation. Trucking and aviation. I wonder which affects it more?

Conclusion: The data at weather station 16239 might be meticulously recorded. But it's nonsense. And "Garbage In, Garbage Out."