Why do skeptics say the sun causes global warming?

Question

They do know, right, that the sun goes through 11 year cycles?

http://en.wikipedia.org/wiki/Image:Solar-cycle-data.png

When the warming trend has lasted for thirty years:

http://en.wikipedia.org/wiki/Image:Instrumental_Temperature_Record.png

Basic logic says that's not possible. If the sun was behind the anomaly wouldn't the temperature be dramatically fluctuating every six years or so?

By the way, for your own benefit, don't pretend it hasn't warmed since '98. You'll look really stupid. No climatologist bases warming trends off comparisons to one year. It's analogous to basing a warming/cooling trend off one extremely cold/hot day millions of years ago, and concluding we've been in a warming/cooling trend since then.

Answer 1

"They do know, right, that the sun goes through 11 year cycles?

http://en.wikipedia.org/wiki/Image:Solar...

When the warming trend has lasted for thirty years:

http://en.wikipedia.org/wiki/Image:Instr...

Basic logic says that's not possible. If the sun was behind the anomaly wouldn't the temperature be dramatically fluctuating every six years or so?"

This is a non sequitur. You obviously don't understand this so I will give you the benefit of the doubt. Just because the sun goes through 11 year cycles does not mean that it cannot warm for 30--that wouldn't even make sense.

The Sun has gotten hotter. The fact that it did so prior to 1950, and then just pretty much just remained so, does not alter its ability to explain warming, even to this day. GHG gasses also have difficulty explaining the shape and timing of the 20th century temperature statistics without significant aerosol contributions.

No matter how suggestive the GHG concentration curves are to the naked eye relative to the plateau in solar activity, without positive feedbacks, anthropogenic GHGs can only account for less than a third of the recent warming. Credible attribution of the rest of the less than 1W/m^2 energy imbalance requires models that can reproduce the observed solar response, and have a much better “match” to the climate than current models.

Read the climate commitment studies of Wigley, et al, and Meehl, et al, to understand how the argument that recent solar activity has not increased is simplistic and wrong. If the level of solar forcing reached prior to 1940 continues (which is unlikely per Solanki), then there will be a solar contribution to the energy imblance resulting in sea level rise for several more centuries. Presumably most of the temperature response occurs in the first few decades, although arguably, that response was delayed by the causes of the midcentury cooling (aerosols, ocean circulations, etc..).