[cogitator]

World CO2 levels have been higher during the last Ice Age ...hardly a case for CO2 being the cause of global warming. What about solar output, certainly the sun isn't constant and is what we are seeing a result of solar changes not CO2? If massive amounts of CO2 cause climate change shouldn't we have seen a temperature shift during WW-II when whole cities were burning worldwide and coal was a major power source?

1. World CO2 levels were not higher during the last Ice Age. The natural peak is about 280 ppm during interglacials, and that's about the value for this interglacial until human activities enhanced the concentration.

2. While solar variability is important, there isn't any evidence it's a factor right now:

The Role of the Sun in 20th Century Climate Change

3. As noted in an earlier post, coal burning was interposed on a slight climate cooling trend, and the sulfate aerosols may have contributed to the cooling. With cleaner air (less sulfate) and more CO2, the warming appears to be the expected to response to more C02. Ocean heat storage forces a climate lag time in response to C02 radiative forcing.

[Monti Cello]

While solar variability is important, there isn't any evidence it's a factor right now:

Why do you suppose that temperatures have stabilized since the mid 90s despite accelerated emissions and amplifying feedback mechanisms?

Could it possibly be related to the long increase in solar output which turned over in the mid 80s? And perhaps have something to do with the low-frequency ENSO peak which turned over in the late 80s, (which also tends to lead the global temperature curve by roughly a decade)?

[palmer]

2. While solar variability is important, there isn't any evidence it's a factor right now:

Only if you ignore this evidence: