Must be global warming causing it.
Scientist Robert W. Felix, author of Not by Fire but by Ice, has long argued that the data in favour of coming mini ice age is more credible.
There are some other scientists that find the mini ice age theory more credible than global warming (and certainly, nonexistent anthropogenic one), among them the Brit Piers Corbyn:
From There's a mini ice age coming, says man who beats weather experts - The Daily Telegraph via The Sydney Morning Herald, 2010 December 21
Back in November, when the Met Office was still doing its "mild winter" schtick, Corbyn said it would be the coldest for 100 years. Indeed, it was back in May that he first predicted a snowy December, and he put his own money on a white Christmas about a month before the Met Office made any such forecast. He said that the Met Office would be wrong about last year's mythical "barbecue summer", and he was vindicated. He was closer to the truth about last winter, too. He seems to get it right about 85 per cent of the time and serious business people - notably in farming - are starting to invest in his forecasts. In the eyes of many punters, he puts the taxpayer-funded Met Office to shame. How on earth does he do it? He studies the Sun. He looks at the flow of particles from the Sun, and how they interact with the upper atmosphere, especially air currents such as the jet stream, and he looks at how the Moon and other factors influence those streaming particles. He takes a snapshot of what the Sun is doing at any given moment, and then he looks back at the record to see when it last did something similar. Then he checks what the weather was like on Earth at the time - and he makes a prophecy. I have not a clue whether his methods are sound or not. But when so many of his forecasts seem to come true, and when he seems to be so consistently ahead of the Met Office, I feel I want to know more. Piers Corbyn believes that the last three winters could be the harbinger of a mini ice age that could be upon us by 2035, and that it could start to be colder than at any time in the last 200 years. ..... < snip > < snip > ..... Allow me to introduce readers to Piers Corbyn, meteorologist and brother of my old chum, bearded leftie MP Jeremy. Piers Corbyn works in an undistinguished office in Borough High Street. He has no telescope or supercomputer. Armed only with a laptop, huge quantities of publicly available data and a first-class degree in astrophysics, he gets it right again and again.
And then, of course, within that, there is the pesky 22 year solar duplex (11+11) sunspot cycle, aka Hale Cycle.