Reuters: France will push the Group of 20 countries to impose a tax on financial transactions to raise billions of dollars to help developing nations fight climate change, President Nicolas Sarkozy said Thursday. Speaking at a conference on forests, Sarkozy repeated his call for a renewed effort on climate change after the “frustrating” Copenhagen conference in December, aiming his fire at “all those who, behind their fine words, want to do nothing.” “Those who don’t want to do anything …