bejohnson
11-18-2005, 09:00 AM
Solar Study Cool on Global Warming Claim (http://www.newsmax.com/archives/ic/2005/11/17/124801.shtml)
Thursday, Nov. 17, 2005 12:43 a.m. EST
Another study has cast doubt on the global warming theory.
Recognizing that the Earth’s climate has been changing since the pre-industrial era, physicist A. Kilcik and his colleagues set out to determine if there is a link between variations in solar activity and changes in the earth’s temperatures, John McCaslin reports in the Washington Times’ Inside the Beltway column.
They compared surface air temperature variations in the U.S. and Japan from 1900 to 1995.
"Our results indicate marked influence of solar-activity variations on the earth’s climate,” the researchers reported in the Journal of Atmospheric and Solar-Terrestrial Physics.
Writes McCaslin: "Which might help explain other historic climate changes, from the ‘Medieval Warm Period’ from the 12th century through the 14th century, to the ‘Little Ice Age’ from the latter half of the 17th century into the early 18th century.
"President Bush may have been correct not to rush his signature onto the Kyoto Protocol treaty on climate change.”
From the research paper:
18 November, 2005
SOLAR INFLUENCE OF CLIMATE CHANGE MORE SIGNIFICANT THAN THOUGHT
(From Journal of Atmospheric and Solar-Terrestrial Physics: "Regional sun-climate interaction" (http://users.bigpond.net.au/jonjayray/green.html) by A. Kilcik. In press, 2005.)
Abstract:
It is a clear fact that the Earth's climate has been changing since the pre-industrial era, especially during the last three decades. This change is generally attributed to three main factors: greenhouse gases (GHGs), aerosols, and solar activity changes. However, these factors are not all-independent. Furthermore, contributions of the above-mentioned factors are still disputed. We sought whether a parallelism between the solar activity variations and the changes in the Earth's climate can be established. For this, we compared the solar irradiance model data reconstructed by J. Lean to surface air temperature variations of two countries: USA and Japan. Comparison was carried out in two categories: correlations and periodicities. We utilized data from a total of 60 stations, 18 in USA and 42 in Japan. USA data range from 1900 to 1995, while Japan data range from 1900 to 1990. Our analyses yielded a 42 per cent correlation for USA and a 79 per cent for Japan between the temperature and solar irradiance. Moreover, both data sets showed similar periodicities. Hence, our results indicate marked influence of solar activity variations on the Earth's climate.
1. Introduction:
It is known that the solar radiation output changes periodically and also that it affects the Earth and near-space environment in various ways, such as the formation of aurora, adverse effects on satellites and communications, etc. Considering the historical evolution of climate changes on Earth, the cold period lasting from the second half of the 17th century to the beginning of the 18th century (1645-1715) is called Little Ice Age, and the corresponding period of practically no activity on the solar surface, Maunder Minimum. Contrary to this, the positive "Medieval Warm Period" (12th-14th centuries) appears to be less distinct; evidence, mostly from Western Europe, did not suggest that this was a global phenomenon (Mann et al., 1999). During this period, temperatures had been about 0.2 øC warmer than compared to 15th-19th centuries, but rather below those of mid-20th century (Intergovernmental Panel on Climate Change (IPCC), 2001). This might have arisen from higher solar activity, as claimed by Eddy (1976).
The Earth climate system has shown irregular changes during the second half of the 20th century, especially for the last three decades. Interest to this subject is therefore continuously increasing. Since the climate system depends on many parameters, such as evaporation, wind, pressure, rainfall, temperature, etc., climate change phenomenon is a very complex problem and the contribution of each parameter to this change is not clear. This change is generally attributed by many scientists including Hegerl et al. (1997) and Lean and Rind (1996) to the increasing concentration of greenhouse gases (GSGs) and aerosols in the atmosphere due to human activity. Among others, Santer et al. (1996), and Wigley et al. (1997) claim that solar forcing and anthropogenic forcing together are enough to explain overall warming trend. Another point due to Crowley (2000) is that the Earth climate system would have been controlled by the Sun before the pre-industrial era, but later anthropogenic effects began to dominate.
To show the Sun-climate connection, many indicators have been used in the literature. For the Sun, these are sunspot numbers (Chambers, 1878), sunspot areas (Nordo, 1955; Dixey, 1924), sunspot decay rates (Hoyt, 1979), solar rotation rates (Sakurai, 1977), solar cycle lengths (Friis-Christensen and Lassen, 1991), geomagnetic aa indices (Cliver and Boriakoff, 1998), solar irradiance changes (Pap, 2002; Floyd et al., 2002; Douglass et al., 2004), solar radius through solar irradiance (Rozelot, 2001), long-term solar activity data obtained from 14C, and 10Be isotope concentrations (Beer et al., 1988). These data sets are compared with climatic parameters such as surface temperature, rainfall, lake level, and air pressure. Amongst these, "temperature is the most commonly, and presumably the most accurately, measured parameter" (Hoyt and Schatten, 1997). Some of these solar activity data sets have shown good agreement with climate parameters, such as the length of the solar cycle and geomagnetic aa index.
2. Data and reduction:
We considered the solar irradiance as a reliable indicator of solar activity. However, observational solar irradiance data exist only since 1978. Hence, solar irradiance data acquired from the World Data Center (WDC) were compared to the data of Ca plage areas and sunspot areas (acquired from National Geophysical Data Center (NGDC)) which are indications of solar chromosphere and photosphere, respectively. Besides, we used surface temperature data acquired from the National Climatic Data Center (NCDC) for analyses. We selected the temperature data according to the following criteria: presence of a minimum of 10 stations on selected regions and availability of uninterrupted monthly temperature data from these stations. Since USA and Japan have better long-term instrumental temperature data than most of the other countries, we used only these two countries' temperature data sets, the temperature being a climate indicator. In this study, temperature data sets covering the period 1900-1990 for Japan and 1900-1995 for USA were selected. These time interval selections are based on the coverage of both pre-industrial and fast-industrial growth era witnessed in these periods (Wiscombe, 1995; Tett et al., 1999). Monthly temperature data were used to obtain the annual mean values for each station. Station averages were then used to obtain the country-wide temperature data for each country. To satisfy equality of station heights and surface areas for both countries, data from only 18 stations of USA and 42 stations of Japan have been used in this study (see Fig. 1). Station heights vary between 3 and 497 m for USA and between 2 and 611 m for Japan.
[...]
5. Conclusion:
We know that a great deal of effort has been put to determine the effects of solar variability on the Earth's climate, and that, to explain the effects of all relevant factors in climate change, one needs to consider a model on a scale of decades to centuries. For the time being, proposed models are not yet of sufficient accuracy to permit any verification (Rozelot, 2001). This study is more a "heuristic" guide to the determination of the principal factors controlling our climate system. We obtained different correlation coefficients between temperatures and solar irradiance depending on the region considered, although we obtained almost identical periodicities for all data sets. Despite the fact that we only used the three-step running average smoothing technique, we obtained a fairly high correlation. On the other hand, our results suggest that atmospheric aerosols have more dominant effect on the Earth's climate than GHGs. Moreover, the existence of similar periodicities for all data sets point out that periodicities in the solar activity manifest themselves in periodic variations on the Earth's surface temperature with almost identical periods. However, prominence of this influence is suppressed by increasing concentration of GHGs in the atmosphere.
Thursday, Nov. 17, 2005 12:43 a.m. EST
Another study has cast doubt on the global warming theory.
Recognizing that the Earth’s climate has been changing since the pre-industrial era, physicist A. Kilcik and his colleagues set out to determine if there is a link between variations in solar activity and changes in the earth’s temperatures, John McCaslin reports in the Washington Times’ Inside the Beltway column.
They compared surface air temperature variations in the U.S. and Japan from 1900 to 1995.
"Our results indicate marked influence of solar-activity variations on the earth’s climate,” the researchers reported in the Journal of Atmospheric and Solar-Terrestrial Physics.
Writes McCaslin: "Which might help explain other historic climate changes, from the ‘Medieval Warm Period’ from the 12th century through the 14th century, to the ‘Little Ice Age’ from the latter half of the 17th century into the early 18th century.
"President Bush may have been correct not to rush his signature onto the Kyoto Protocol treaty on climate change.”
From the research paper:
18 November, 2005
SOLAR INFLUENCE OF CLIMATE CHANGE MORE SIGNIFICANT THAN THOUGHT
(From Journal of Atmospheric and Solar-Terrestrial Physics: "Regional sun-climate interaction" (http://users.bigpond.net.au/jonjayray/green.html) by A. Kilcik. In press, 2005.)
Abstract:
It is a clear fact that the Earth's climate has been changing since the pre-industrial era, especially during the last three decades. This change is generally attributed to three main factors: greenhouse gases (GHGs), aerosols, and solar activity changes. However, these factors are not all-independent. Furthermore, contributions of the above-mentioned factors are still disputed. We sought whether a parallelism between the solar activity variations and the changes in the Earth's climate can be established. For this, we compared the solar irradiance model data reconstructed by J. Lean to surface air temperature variations of two countries: USA and Japan. Comparison was carried out in two categories: correlations and periodicities. We utilized data from a total of 60 stations, 18 in USA and 42 in Japan. USA data range from 1900 to 1995, while Japan data range from 1900 to 1990. Our analyses yielded a 42 per cent correlation for USA and a 79 per cent for Japan between the temperature and solar irradiance. Moreover, both data sets showed similar periodicities. Hence, our results indicate marked influence of solar activity variations on the Earth's climate.
1. Introduction:
It is known that the solar radiation output changes periodically and also that it affects the Earth and near-space environment in various ways, such as the formation of aurora, adverse effects on satellites and communications, etc. Considering the historical evolution of climate changes on Earth, the cold period lasting from the second half of the 17th century to the beginning of the 18th century (1645-1715) is called Little Ice Age, and the corresponding period of practically no activity on the solar surface, Maunder Minimum. Contrary to this, the positive "Medieval Warm Period" (12th-14th centuries) appears to be less distinct; evidence, mostly from Western Europe, did not suggest that this was a global phenomenon (Mann et al., 1999). During this period, temperatures had been about 0.2 øC warmer than compared to 15th-19th centuries, but rather below those of mid-20th century (Intergovernmental Panel on Climate Change (IPCC), 2001). This might have arisen from higher solar activity, as claimed by Eddy (1976).
The Earth climate system has shown irregular changes during the second half of the 20th century, especially for the last three decades. Interest to this subject is therefore continuously increasing. Since the climate system depends on many parameters, such as evaporation, wind, pressure, rainfall, temperature, etc., climate change phenomenon is a very complex problem and the contribution of each parameter to this change is not clear. This change is generally attributed by many scientists including Hegerl et al. (1997) and Lean and Rind (1996) to the increasing concentration of greenhouse gases (GSGs) and aerosols in the atmosphere due to human activity. Among others, Santer et al. (1996), and Wigley et al. (1997) claim that solar forcing and anthropogenic forcing together are enough to explain overall warming trend. Another point due to Crowley (2000) is that the Earth climate system would have been controlled by the Sun before the pre-industrial era, but later anthropogenic effects began to dominate.
To show the Sun-climate connection, many indicators have been used in the literature. For the Sun, these are sunspot numbers (Chambers, 1878), sunspot areas (Nordo, 1955; Dixey, 1924), sunspot decay rates (Hoyt, 1979), solar rotation rates (Sakurai, 1977), solar cycle lengths (Friis-Christensen and Lassen, 1991), geomagnetic aa indices (Cliver and Boriakoff, 1998), solar irradiance changes (Pap, 2002; Floyd et al., 2002; Douglass et al., 2004), solar radius through solar irradiance (Rozelot, 2001), long-term solar activity data obtained from 14C, and 10Be isotope concentrations (Beer et al., 1988). These data sets are compared with climatic parameters such as surface temperature, rainfall, lake level, and air pressure. Amongst these, "temperature is the most commonly, and presumably the most accurately, measured parameter" (Hoyt and Schatten, 1997). Some of these solar activity data sets have shown good agreement with climate parameters, such as the length of the solar cycle and geomagnetic aa index.
2. Data and reduction:
We considered the solar irradiance as a reliable indicator of solar activity. However, observational solar irradiance data exist only since 1978. Hence, solar irradiance data acquired from the World Data Center (WDC) were compared to the data of Ca plage areas and sunspot areas (acquired from National Geophysical Data Center (NGDC)) which are indications of solar chromosphere and photosphere, respectively. Besides, we used surface temperature data acquired from the National Climatic Data Center (NCDC) for analyses. We selected the temperature data according to the following criteria: presence of a minimum of 10 stations on selected regions and availability of uninterrupted monthly temperature data from these stations. Since USA and Japan have better long-term instrumental temperature data than most of the other countries, we used only these two countries' temperature data sets, the temperature being a climate indicator. In this study, temperature data sets covering the period 1900-1990 for Japan and 1900-1995 for USA were selected. These time interval selections are based on the coverage of both pre-industrial and fast-industrial growth era witnessed in these periods (Wiscombe, 1995; Tett et al., 1999). Monthly temperature data were used to obtain the annual mean values for each station. Station averages were then used to obtain the country-wide temperature data for each country. To satisfy equality of station heights and surface areas for both countries, data from only 18 stations of USA and 42 stations of Japan have been used in this study (see Fig. 1). Station heights vary between 3 and 497 m for USA and between 2 and 611 m for Japan.
[...]
5. Conclusion:
We know that a great deal of effort has been put to determine the effects of solar variability on the Earth's climate, and that, to explain the effects of all relevant factors in climate change, one needs to consider a model on a scale of decades to centuries. For the time being, proposed models are not yet of sufficient accuracy to permit any verification (Rozelot, 2001). This study is more a "heuristic" guide to the determination of the principal factors controlling our climate system. We obtained different correlation coefficients between temperatures and solar irradiance depending on the region considered, although we obtained almost identical periodicities for all data sets. Despite the fact that we only used the three-step running average smoothing technique, we obtained a fairly high correlation. On the other hand, our results suggest that atmospheric aerosols have more dominant effect on the Earth's climate than GHGs. Moreover, the existence of similar periodicities for all data sets point out that periodicities in the solar activity manifest themselves in periodic variations on the Earth's surface temperature with almost identical periods. However, prominence of this influence is suppressed by increasing concentration of GHGs in the atmosphere.