Monday, December 10, 2012

New paper finds a large increase of solar radiation in Greece since 1990; dwarfs alleged effect of CO2

A new paper published in the International Journal of Climatology examines solar radiation at the Earth surface in Greece from 1993-2011 and finds a significant increase after 1990 of 0.33% per year. This upward trend in solar radiation would equate to about 14.1 Wm-2 over the past 18 years, dwarfing the alleged effect of CO2 at the Earth surface during that same period [0.13 Wm-2] by a factor of more than 108 times. The paper adds to many others showing that solar radiation at the Earth surface significantly increased beginning in the 1980's and could more than account for the tiny global warming observed [0.4C] since the ice age scare of the 1970's.

The math:

"solar constant" = 1361 Wm-2

[(1361-30%albedo)*.0033]/4 = 0.785 Wm-2 change in insolation [global average, would actually be higher for Greece being relatively close to the equator]

0.785*18 years = 14.1 Wm-2

Alleged forcing from CO2 change from 1993-2011 per the IPCC formula:

5.35*ln(391.62/357.07) = 0.49 Wm-2 at the top of the atmosphere

0.49/3.7 = 0.13 Wm-2 alleged CO2 forcing at the surface of the Earth

Prior posts on trends in solar irradiance and cloudiness

  1. A. F. Bais*
  2. Th. Drosoglou, 
  3. C. Meleti, 
  4. K. Tourpali, 
  5. N. Kouremeti

The variability of shortwave downward solar irradiance (SDR) received at Earth's surface over Thessaloniki, Greece for the period 1993–2011 is investigated, focusing on the effects from the aerosols variability on the irradiance trends derived for different solar zenith angles (SZA). Linear trends have been calculated for the entire dataset, for cloud-free cases, and for different SZAs, separately for each season. The global upward trend in SDR after 1990 (0.33% year−1) is reconfirmed and is found to depend strongly on SZA, ranging from ∼0.1 to +0.6% year−1. The long term changes in aerosols in conjunction with the local aerosol patterns result in differences of up to 0.1% year−1 in the derived trends in SDR between morning and afternoon hours. Finally, based on the analysis of the cumulative sums of the differences in monthly averages of SDR from the long term mean we report signs of a slowdown in the upward trend in SDR during the beginning of the 2000s

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