Guardian: Much of the $100bn a year needed by 2020 to compensate poor countries for the effects of climate change will come from carbon taxes and the auction of carbon permits rather than new taxes on financial transactions or transport levies, it was suggested today. Economists and politicians have been asked to find ways of raising the money by the UN secretary general, Ban Ki-Moon. But with only three months to go before countries meet again to thrash out a new climate agreement, the …