More empirical evidence that the so called global warming is to a very significant extent caused by the urban heat island effect!
Keep in mind: Global warming is a hoax and climate change is a religion! It is being used as a pretext by Big Government and the elite to interfere with our lives. It is among the greatest scams and scandals of at least the last 30 years!
"... Spencer and Christy’s method uses millions of thermometer observations to quantify the well-known tendency for urban areas to be warmer than rural areas. By relating difference in temperature to differences in population density, in six classes of population density and in 22 different historical periods between 1880 and 2020, the researchers were able to quantify the average rate of warming as a function of population density.
“While the statistical signal of urban warming was rather weak due to noise in the data from other non-urbanization effects on weather, it was very consistent, showing up in all six classes of population density across all 22 historical periods,” Spencer says.
“One of the interesting results was that the most rapid warming occurs as for population growth at the lowest population densities,” Spencer notes. “Then in heavily urbanized areas the warming reaches a peak, with little additional warming as population increases.”
The issue is important because the estimation of the rate of warming in the U.S. due to climate change can be influenced by non-climate processes, such as the Urban Heat Island effect, which would exist even without global warming. For the period 1895 to 2023, it was found that 8 percent of the rural warming trend was due to urbanization effect, increasing to about 65 percent of the observed warming trend for suburban and urban locations. ..."
"A novel method is described for quantifying average urban heat island (UHI) warming since 1895 in contiguous U.S. (CONUS) summer air temperature data. The method quantifies the sensitivity of Global Historical Climatology Network (GHCN) station raw temperature to station-centered population density (PD). Specifically, closely spaced station pair differences in monthly raw (non-homogenized) TAVG (the average of daily maximum and minimum temperature) and PD are sorted by station pair average PD into six PD classes, and linear regression estimates of the temperature sensitivity to population density change (dTAVG/dPD) are made for each class for historical periods ranging from 1 to 21 years in length. Every one of the resulting six sensitivity relationships in each of 22 historical periods from 1880 to 2020 are found to be positive, and their magnitudes allow construction of station-average urban heat island temperature (TUHI) curves as a function of population density.
When applied to the history of population changes at each CONUS station location (1895–2023) and grouped into four categories of station population density, the resulting TUHI warming trends range from 8% of observed TAVG warming for the most rural category of stations to about 65% of observed warming for suburban and urban categories. Across all stations the UHI warming amounts to 22% of the observed raw GHCN warming trend, (+0.016 versus +0.072 °C decade−1). The method provides an independent way to quantify station-average UHI warming over time."
Urban Heat Island warming effects related to population density are quantified for the first time (this article is written by the first author of the above research study)
No comments:
Post a Comment