Former Prime Minister Tony Blair has called for a "global environment revolution" to tackle climate change. Mr Blair is on a visit to Japan to discuss global greenhouse gas targets. In a speech to a meeting of G8 ministers building on the 2005 Gleneagles summit, he stressed the need for a "global deal". He suggested it should be led by the UN and that failure to act on climate change "would be deeply and unforgivably irresponsible". During his visit, organised by Climate Group, Mr Blair is due to meet climate change experts from China, Japan, Europe and the US.