We keep being told that the ice and snow this winter means that global warming is a myth. It seems that I can forget all the problems with fossil fuels and carbon dioxide and that we can continue with business as usual.

However, it’s not difficult to show that this isn’t the case, and it is even possible to explain that the cold is related to a warming world.

Despite all the snow, there’s no evidence that global warming has stopped. Indeed, this would be scientifically impossible unless CO2 becomes quite a different chemical.

Though it’s reasonable to concentrate on the current weather in our own little patch of the globe, and to forget the temperatures earlier in the year or a couple of years back, we really do have to consider what is happening in the rest of the world.

It certainly isn’t cold where the England cricket team is playing, and while we shiver, the Hudson Bay area in northern Canada is free of ice and setting record high temperatures for autumn. Overall, 2010 is likely to be the warmest year since records began, or it will equal the two other very warm years, 1998 and 2005. Indeed, November recorded the highest-ever global figures for that month, and the previous 12-month period was the warmest-ever.

The last decade has certainly been the warmest-ever measured, and this year at least 18 countries set new record-high temperatures, as the Russians are well aware with top temperatures soaring to more than 40C.

This is all the more surprising as it coincides with La Nina’s cold water in the Pacific and the lowest solar input for many decades, both which reduce temperatures.

Our normal mild and wet winters are due to air from the Atlantic blowing from the West, and this is all determined by the high pressure over the Azores, to the South, and the low pressure over Iceland, to the North.

The development of these winds is determined by the jet stream, at more than 30,000ft above sea level, and in winter it is normally well to the north of Shetland, allowing the mild Atlantic air to sweep over the UK.

However, for the last couple of winters this boundary has been to the South meaning that we are covered by Arctic and Russian air, cold and dry until it moves over the North Sea where it picks up the moisture that gives snow.

The reason for this is that the jet stream has taken up a new position because of the warmth from the seas to the north of Canada that are now ice-free in early winter, and this is due to global warming.