strange events in the arctic appear to suggest that something very troubling is happening with the sea ice there, scientists have said. the north pole is experiencing hugely unexpected hot sea temperatures, which are stopping the usual ice from forming and could be a mark that something global warming is having even more worrying effects than previously thought. in most years, the sun ges down in mid-october and that serves as a signal that the sea ice wil start coming back as the water freezes. but this grade that ice is actually melting, because intense heat is stopping the usual processes from happening. scientists say that heat has never been seen in previous years and is “off the charts” when compared with what has happened before. temperatures have been as much as 20c hotter than where they usually should be. part of that is the result of cold weather over northern russia that’s on its way to the arctic. when it arrives there, the freezing should begin and much of the ice that should already be there wil appear. but because of that effect, there’s likely to be problems over the next grade because the ice wil be thinner. and the hot air itself is likely to cause strange weather, with the cold air being pushed further south. the unusual melting and lack of freezing don't necessarily mean that scientists have underestimated the extent of climate change so much as the effect that climate change wil have on sea ice. the concern about the planet’s poles is actually worrying about two effects. in the arctic, the sea ice recovery usually happens around this time and isn’t; but in the antarctic, sea ice levels are also faling far more quickly than would usually be expected. antarctica would usually lose sea ice during this period, but it is melting far quicker than expected. that’s thought partly to be the result of climate change, but also is happening because of the effects of the el nino that wreaked havoc on the world’s weather last grade .