New paper concludes solar luminosity has decreased for the past 20 years

[bascule]

http://news.bbc.co.uk/1/hi/uk/6290228.stm

 

Can we put aside arguments about the effects of solar forcings yet?

[Reaper]

The hypothesis that the sun was responsible seemed very suspicious to begin with.

[bascule]

The hypothesis that the sun was responsible seemed very suspicious to begin with.

 

The sun has been one of the primary drivers of climate change for quite some time. Not anymore.

 

Man is the primary driver of climate change now.

[Reaper]

I understood that, but it seemed suspicious just simply because CO2 emissions have increased by over 100 ppm since the industrial revolution.

 

The first 50 ppm came between the beginning of the industrial revolution and the 1970's. The other 50 ppm was poured into the atmosphere in just a little over 30 years.

 

Also, solar activity was very high about 8000 years ago. Solar activity has been linked to the occurrence of ice ages. But it is also true that CO2 levels never went as high as it is today over 8000 years ago.

 

And if you really want to go back into the past, say millions of years, the sun wasn't as bright as it was today. But it was much warmer in the past, especially during the Mesozoic, because of large concentrations of CO2, tectonic activity and sea levels during the era. Also, the continents were not as spread apart as they are today. For a long while there was one big super-continent. These all played a part in the climate of the era.

[1veedo]

http://news.bbc.co.uk/1/hi/uk/6290228.stm

 

Can we put aside arguments about the effects of solar forcings yet?

This is old news. The new study just verifies previous studies, which is actually fairly important in peer-review. See for example,

 

http://www.pmodwrc.ch/pmod.php?topic=tsi/composite/SolarConstant

Sami K. Solanki's graphic(can't find the study, I've just been using the image), http://www.mps.mpg.de/images/projekte/sun-climate/climate.gif

http://www.ngdc.noaa.gov/stp/SOLAR/ftpsunspotnumber.html