OK, let's pretend for a second that man-made CO2 output has a significant impact on raising the Earth's temperature.
Let's also assume we are "due" for another ice age... (plenty of debate on this but since we are making wild leaps of faith on the first point, let's do the same here)
Would you would rather cut CO2 emissions NOW and have 100-500 years of "perfect" climate but suffer a catastrophic ice age or would you be willing to suffer 100-500 years of global warming and effectively stave off an ice age entirely?
It will be the height of irony if the effect of us curbing global warming is that we lose the opportunity to avoid mass extinction.
Of course, all of this is wild conjecture based on incomplete data and suspect models... which makes it a perfect fit for any discussion about climate change.
(btw we'll just ignore solar activity because , well, that seems to be an ok thing to do in many climate discussions)