Link

http://www.skepticalscience.com/solar-activity-sunspots-global-warming.htm

As supplier of almost all the energy in Earth's climate, the sun has a strong influence on climate. A comparison of sun and climate over the past 1150 years found temperatures closely match solar activity (Usoskin 2005). However, after 1975, temperatures rose while solar activity showed little to no long term trend. This led the study to conclude "during these last 30 years the solar total irradiance, solar UV irradiance and cosmic ray flux has not shown any significant secular trend, so that at least this most recent warming episode must have another source."

In fact, a number of independent measurements of solar activity indicate the sun has shown a slight cooling trend since 1960, over the same period that global temperatures have been warming. Over the last 35 years of global warming, sun and climate have been moving in opposite directions. An analysis of solar trends concluded that the sun has actually contributed a slight cooling influence in recent decades (Lockwood 2008).

Praktisch das gesamte Klimasystem der Erde wird von der Energie der eintreffenden Sonnenstrahlen angetrieben. Daher hat die Sonne natürlich einen starken Einfluss auf das Erdklima. Ein Vergleich der globalen Mitteltemperaturen und der Sonnenaktivität der letzten 1150 Jahre zeigt große Übereinstimmung (Usoskin 2005). Nach 1975 stiegen die Temperaturen jedoch stark an, während die Sonnenaktivität fast keinen Trend zeigte. Daraus wurde der Schluss gezogen, dass "während der letzten 30 Jahre weder die gesamte solare Einstrahlung, noch die UV-Einstrahlung, noch der Fluss kosmischer Strahlung einen signifikanten Langzeittrend zeigten, weshalb die jüngste Erwärmung einen anderen Grund haben muss."

Verschiedene unabhängige Messungen der solaren Aktivität zeigen sogar einen leichten Abkühlungstrend seit 1960, im gleichen Zeitraum also, in dem die Temperaturen am stärksten angestiegen sind. In den letzten 30-40 Jahren haben sich Temperatur und Sonnenaktivität also in unterschiedliche Richtungen entwickelt. Eine Analyse dieser Trends zieht die Schlussfolgerung, dass die Sonne sogar einen leicht kühlenden Einfluss auf das Klima der letzten Jahrzehnte hatte (Lockwood 2008).

Figure 1: Annual global temperature change (thin light blue) with 11 year moving average of temperature (thick dark blue). Temperature from NASA GISS. Annual Total Solar Irradiance (thin light red) with 11 year moving average of TSI (thick dark red). TSI from 1880 to 1978 from Solanki. TSI from 1979 to 2009 from PMOD.

Bild 1: Jährliche globale Mitteltemperatur und laufendes 11-Jahres-Mittel (rot) sowie jährliche gesamte solare Einstrahlung ("Solarkonstante") und laufendes 11-Jahres-Mittel (blau). Temperaturen nach NASA GISS. Einstrahlung der Sonne von 1880 bis 1978 nach Solanki, von 1979 bis 2009 nach PMOD.

Other studies on solar influence on climate

This conclusion is confirmed by many studies finding that while the sun contributed to warming in the early 20th Century, it has had little contribution (most likely negative) in the last few decades:

• Erlykin 2009: "We deduce that the maximum recent increase in the mean surface temperature of the Earth which can be ascribed to solar activity is 14% of the observed global warming"
• Benestad 2009: "Our analysis shows that the most likely contribution from solar forcing a global warming is 7 ± 1% for the 20th century and is negligible for warming since 1980."
• Lockwood 2008: "It is shown that the contribution of solar variability to the temperature trend since 1987 is small and downward; the best estimate is −1.3% and the 2σ confidence level sets the uncertainty range of −0.7 to −1.9%."
• Lockwood 2008: "The conclusions of our previous paper, that solar forcing has declined over the past 20 years while surface air temperatures have continued to rise, are shown to apply for the full range of potential time constants for the climate response to the variations in the solar forcings."
• Ammann 2007: "Although solar and volcanic effects appear to dominate most of the slow climate variations within the past thousand years, the impacts of greenhouse gases have dominated since the second half of the last century."
• Lockwood 2007: "The observed rapid rise in global mean temperatures seen after 1985 cannot be ascribed to solar variability, whichever of the mechanism is invoked and no matter how much the solar variation is amplified."
• Foukal 2006 concludes "The variations measured from spacecraft since 1978 are too small to have contributed appreciably to accelerated global warming over the past 30 years."
• Scafetta 2006 says "since 1975 global warming has occurred much faster than could be reasonably expected from the sun alone."
• Usoskin 2005 conclude "during these last 30 years the solar total irradiance, solar UV irradiance and cosmic ray flux has not shown any significant secular trend, so that at least this most recent warming episode must have another source."
• Solanki 2004 reconstructs 11,400 years of sunspot numbers using radiocarbon concentrations, finding "solar variability is unlikely to have been the dominant cause of the strong warming during the past three decades".
• Haigh 2003 says "Observational data suggest that the Sun has influenced temperatures on decadal, centennial and millennial time-scales, but radiative forcing considerations and the results of energy-balance models and general circulation models suggest that the warming during the latter part of the 20th century cannot be ascribed entirely to solar effects."
• Stott 2003 increased climate model sensitivity to solar forcing and still found "most warming over the last 50 yr is likely to have been caused by increases in greenhouse gases."
• Solanki 2003 concludes "the Sun has contributed less than 30% of the global warming since 1970".
• Lean 1999 concludes "it is unlikely that Sun–climate relationships can account for much of the warming since 1970".
• Waple 1999 finds "little evidence to suggest that changes in irradiance are having a large impact on the current warming trend."
• Frolich 1998 concludes "solar radiative output trends contributed little of the 0.2°C increase in the global mean surface temperature in the past decade"

Deutsche Übersetzung (nicht mehr aktuell!)

Da die Sonne fast die gesamte Energie für das Erdklima liefert, hat sie selbstverständlich einen starken Einfluss auf den Klimawandel. Deshalb gibt es auch viele Studien, die den Zusammenhang zwischen Sonnenaktivität und globalen Temperaturen untersuchen.

As supplier of almost all the energy in Earth's climate, the sun certainly has a strong influence on climate change. Consequently there have been many studies examining the link between solar variations and global temperatures.

Der Zusammenhang zwischen Sonnenaktivität und Temperatur

Die von den Skeptikern am häufigsten zitierte Studie stammt von finnischen und deutschen Wissenschaftlern. Die Studie kommt zu dem Schluss, dass die Sonne in den letzten 60 Jahren aktiver war als irgendwann sonst in den vergangenen 1150 Jahren (Usoskin 2005). Sie fanden auch eine enge Übereinstimmung zwischen Temperaturen und Sonnenaktivität.

The correlation between solar activity and temperature

The most commonly cited study by skeptics is a study by scientists from Finland and Germany that finds the sun has been more active in the last 60 years than anytime in the past 1150 years (Usoskin 2005). They also found temperatures closely correlate to solar activity.

Eine entscheidende Erkenntnis der Studie war jedoch, dass die Übereinstimmung zwischen Sonnenaktivität und Temperatur um 1975 herum endete. Zu diesem Zeitpunkt stiegen die Temperaturen an während die Sonnenaktivität gleich blieb. Dies führte die Wissenschaflter zu der Schlussfolgerung, dass "während der letzten 30 Jahre die gesamte Bestrahlungsdichte der Sonne, die UV-Strahlung der Sonne und die kosmische Einstrahlung keinen langfristigen Trend gezeigt haben, Weshalb zumindest die jüngste Erwärmungsphase eine andere Ursache haben muss."

However, a crucial finding of the study was the correlation between solar activity and temperature ended around 1975. At that point, temperatures rose while solar activity stayed level. This led them to conclude "during these last 30 years the solar total irradiance, solar UV irradiance and cosmic ray flux has not shown any significant secular trend, so that at least this most recent warming episode must have another source."

Mit anderen Worten, die von den Sketpikern am häufigsten zitierte Studie kommt tatsächlich zu dem Schluss, dass die Sonne die globale Erwärmung nicht verursachen kann. Die Beweise für die enge Übereinstimmung zwischen der Sonne und den Temperaturen auf der Erde in der Vergangenheit, belegen auch ihre Schluldlosigkeit für die heutige Klimaerwärmung.

In other words, the study most quoted by skeptics actually concluded the sun can't be causing global warming. The evidence that establishes the sun's close correlation with the Earth's temperature in the past also establishes its blamelessness for global warming today.

Weitere Studien zum Einfluss der Sonne auf das Klima

Diese Schlussfolgerung wird von vielen Studien bestätigt, die den Beitrag des Einflusses der Sonne auf die jüngste globale Erwärmung bewerten:

Other studies on solar influence on climate

This conclusion is confirmed by many studies quantifying the amount of solar influence in recent global warming:

• Erlykin 2009: "We deduce that the maximum recent increase in the mean surface temperature of the Earth which can be ascribed to solar activity is 14% of the observed global warming"
• Benestad 2009: "Our analysis shows that the most likely contribution from solar forcing a global warming is 7 ± 1% for the 20th century and is negligible for warming since 1980."
• Lockwood 2008: "It is shown that the contribution of solar variability to the temperature trend since 1987 is small and downward; the best estimate is −1.3% and the 2σ confidence level sets the uncertainty range of −0.7 to −1.9%."
• Lockwood 2008: "The conclusions of our previous paper, that solar forcing has declined over the past 20 years while surface air temperatures have continued to rise, are shown to apply for the full range of potential time constants for the climate response to the variations in the solar forcings."
• Ammann 2007: "Although solar and volcanic effects appear to dominate most of the slow climate variations within the past thousand years, the impacts of greenhouse gases have dominated since the second half of the last century."
• Lockwood 2007: "The observed rapid rise in global mean temperatures seen after 1985 cannot be ascribed to solar variability, whichever of the mechanism is invoked and no matter how much the solar variation is amplified."
• Foukal 2006 concludes "The variations measured from spacecraft since 1978 are too small to have contributed appreciably to accelerated global warming over the past 30 years."
• Scafetta 2006 says "since 1975 global warming has occurred much faster than could be reasonably expected from the sun alone."
• Usoskin 2005 conclude "during these last 30 years the solar total irradiance, solar UV irradiance and cosmic ray flux has not shown any significant secular trend, so that at least this most recent warming episode must have another source."
• Solanki 2004 reconstructs 11,400 years of sunspot numbers using radiocarbon concentrations, finding "solar variability is unlikely to have been the dominant cause of the strong warming during the past three decades".
• Haigh 2003 says "Observational data suggest that the Sun has influenced temperatures on decadal, centennial and millennial time-scales, but radiative forcing considerations and the results of energy-balance models and general circulation models suggest that the warming during the latter part of the 20th century cannot be ascribed entirely to solar effects."
• Stott 2003 increased climate model sensitivity to solar forcing and still found "most warming over the last 50 yr is likely to have been caused by increases in greenhouse gases."
• Solanki 2003 concludes "the Sun has contributed less than 30% of the global warming since 1970".
• Lean 1999 concludes "it is unlikely that Sun–climate relationships can account for much of the warming since 1970".
• Waple 1999 finds "little evidence to suggest that changes in irradiance are having a large impact on the current warming trend."
• Frolich 1998 concludes "solar radiative output trends contributed little of the 0.2°C increase in the global mean surface temperature in the past decade"

Ocean Thermal Inertia

Usoskin 2005 also found that over 1150 years, temperature lagged solar activity by 10 years. Due to ocean thermal inertia, it takes the climate a decade to catch up to long term changes in solar activity. This is exactly what's observed in the 20th century - in the early decades, solar activity rose sharply with temperature lagging a decade behind. When solar activity leveled out in the 40's, so too did global temperatures.