If this is happening, then it requires either more heat or lower atmospheric pressure to evaporate water off the oceans and put it into the atmosphere to form water saturated clouds. If geology is any indicator, the ice forms fairly quickly, indicating large amounts of water being delivered fairly rapidly. "Global Warming" may be the mechanish that does indeed cause ice ages.
It's not Global Warming, it's Ocean Warming
"Research shows that there was "a sudden and dramatic rise" in carbon dioxide in the Earth's atmosphere at the dinosaur extinction of 65 million years ago. A recent report attributes the rise in CO2 levels to an asteroid impact. See http://news.bbc.co.uk/1/hi/sci/tech/2038599.stm"
"I disagree. I think today's rise in CO2 levels can be attributed to our warming oceans. After all, the oceans are known as a carbon dioxide "sink," especially when the water is cold."
"But as the water warms up, it releases CO2 into the atmosphere. This happens in much the same way that a warm bottle of home-brewed root beer will release CO2. And if you give that CO2 no way to escape, the bottle will explode."
"We've got it backwards. We've got cause and effect in reverse."
"The CO2 is not causing global warming. Instead, our warming oceans are releasing CO2 into the atmosphere."
"It's not global warming, it's ocean warming, and it's leading us into an ice age."
Aye, that's the problem. Less energy (say, through a cloud of dust from a so-called supervolcano eruption) reaching the oceans will alter the hydrologic cycle. Precipitation depends on evaporation, and there's simply no way for a natural process to cloud over the land (to prevent melting of the snow that continues to fall) while not clouding over the oceans (in order to produce the precipitation).