CHRIS HUHNE, the Energy Secretary, soldiered through a gruelling hour in the Commons yesterday, setting out the Government's policy on climate change, as he awaits a decision from Essex police on whether he is to be the subject of a criminal investigation.  His Commons appearance was preceded by a day's speculation on whether he would show his face at all. Downing Street had said the previous day that the Government's ambitious plans for carbon reduction would be set out in a written statement. But Mr Huhne reportedly insisted on making a personal