Independent: Scientists are warning that an Antarctic ice shelf the size of Northern Ireland is on the verge of disintegration, even though it is now the middle of the southern hemisphere’s winter. The European Space Agency says new satellite pictures show that the Wilkins shelf – the largest to be threatened so far – is “hanging by its last thread”. Extending for approximately 5,600 square miles, it has been held in place by a thin ice bridge connecting it to an island, but this is now …