Read here. IPCC Climategate scientists have conveniently dismissed the influence of the Sun on the climate, by simply rejecting any solar science being included in the IPCC reports. Outside of the IPCC though, peer-reviewed research is determining that solar, not CO2, is the primary climate driver.
"The researchers' final conclusion was that "quasi-100-year fluctuations of solar activity may be the primary driving force of temperature during the past 6000 years in China." And since their data indicate that peak Medieval Warm Period temperatures were higher than those of the recent past, it is not unreasonable to assume that the planet's recent warmth may have been solar-induced as well."