B Johnson (in the Weekend Sun, December 6, page 40) claims the media are biased by highlighting hot weather records and ignoring extreme cold events, such as one sweeping through the US, so as to not undermine the validity of the global warming threat.

To the contrary, scientists have explained how such cold outbursts are triggered by the rising air temperatures weakening the polar vortex which normally ‘ring fences in' the Arctic (and Antarctic) air.

This is like breaking open the fridge door, allowing all the cold air to spill out, as it famously did last year all the way to Florida and also over Europe, south to the Mediterranean.

Meanwhile warm air was drawn into the Arctic, raising temperatures there to record levels with the North Pole briefly warmer than London. It is all part of the arsenal of climate extremes powered by global warming - no ‘political agenda' in sight!

Any perceived media bias is entirely incidental to the reality of climate change. This is now kicking in exactly as predicted, but sooner and faster due to the world's failure to act.

P Otway, Omokoroa.