This is not a new theory — but, other articles point out that we're over 1,000 years overdue for an ice age. According to that theory, the greenhouse gases released over the past 8,000 years’ first from agriculture, then, more recently from industrialization, have kept the ice age at bay.
Clearly, this would be a good thing. Especially, here in Canada (and Alaska), which was covered by miles-thick ice for many thousands of years.
Here's an article that claims we could avoid the next 5 ice ages, by burning up all the fossil fuels on the planet:
http://www.soton.ac.uk/mediacentre/news/2007/aug/07_100.shtml
The problem with Ice Ages is that they just happen, the Earth was warming quite nicely 12,000 years ago and then the Younger Dryas and a 1000 years of real bad weather then 7000 years of good weather with assorted nasties spaced at intervals.
Reminds me of an old Polish woman's joke, "The first child can come at any time the second takes nine months."