Its the Sun, stupid ! or is it ?

In 2007, Habibullo Abdussamatov, head of space research at St. Petersburg's Pulkovo Astronomical Observatory in Russia issued a controversial theory suggesting that changes in the Sun's activity were the cause for global warming and not raising levels of greenhouse gases such as CO2.   As evidence, Abdussamatov pointed to warming on Mars reflected in decreasing carbon dioxide ice caps on the poles of Mars over a 3 martian year period.  

Abdussmatov took this evidance and suggested that planetary warming is uniform across the solar system and is a product of solar activity.   However, this is not at all the case.   Indeed, for the past 35 years the Sun has actualy been in a slight cooling phase, generating slightly less heat, not more.  The past 10 years have also been in an unusualy long solar minimum period, a period in which solar flare and sunspot activity is lower than average.  Note that this same period also represents one of the hottest decades in recorded history since mankind has been measuring temperatures.

Therefore, it is clear that something interesting is happening on Mars, but it is not a result of higher solar activity and does not explain the global warming effect we are experiencing on Earth.

Graph : Global Average Earth Temperature (RED) and Sun Activity / Radiated Heat (BLUE)

Note that solar activity does cause increases in atmospheric temperaters on Earth, this is a given, however, the pronounced global warming effect we have been tracking since the mid 20th Century does not reflect any increase in solar activity, indeed, most of Earth's recent warming occurred while the Sun was in a cooling phase.  The Sun is not the driving factor in warming (currently), however, when the Sun does enter a new highly active (Solar Maximum) phase, the effects of greenhouse gas driven global warming will be accelerated and magnified by the increased warming from the Sun.  We should be entering a period of solar maximum very soon.

[ sources (controversial theory and skeptics) : http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html ; http://news.bbc.co.uk/2/hi/science/nature/3869753.stm ]


[ sources (refuting points) : http://www.skepticalscience.com/solar-activity-sunspots-global-warming.htm ; http://rspa.royalsocietypublishing.org/content/464/2094/1387.abstract ; http://adsabs.harvard.edu/abs/2009JGRD..11414101B ; http://arxiv.org/PS_cache/arxiv/pdf/0901/0901.0515v1.pdf ; http://www.skepticalscience.com/acrim-pmod-sun-getting-hotter.htm ]