The annual rate of reduction of carbon emissions per unit of GDP needed to limit global warming to 2ºC, has passed a critical threshold according to new analysis from PwC. And the report's author warn the rate of reduction now required has never been achieved before and add: "This isn't about shock tactics, it's simple maths." The analysis in the PwC Low Carbon Economy Index, measuring developed and emerging economies progress towards reducing emissions linked to economic output. It demonstrates that at current rates of emissions growth at least 6C degrees of warming could be possible by the end of the century.