Seeing snow in Bremen is about as common as hitting a lottery jackpot,but ever since December the stuff has been all too real. This winter has been tough across Europe. Temperatures of minus 20 degrees Celsius have not been uncommon.Not only northern Europe,but countries in the southern part of the continent,like Spain,are dealing with ice and huge snow drifts. Weather scientists say in these conditions it's not the usual Atlantic winds blowing across the European continent but a blast from the north. How does science explain the weather extremes: is it chance,or is it climate change? Report by Maria Lesser (DW)