A “warm, crazy” winter has left sea ice in the Arctic at its lowest levels on record for the season, scientists said.

SCIENTISTS fear global warming has passed an ominous tipping point after Nasa satellite data showed the already relentless melting of the Arctic increased greatly during the northern hemisphere’s hot summer months.

The North Pole could be free of ice during the summer by 2040 thanks to the dramatic effects of global warming, a new scientific study has warned.

New satellite observations show that sea ice in the Arctic is melting faster while air temperatures in the region are rising sharply, scientists say.