PricewaterhouseCoopers (PwC) has released a report entitled the Low Carbon Economy Index, which analyses the amount of carbon emitted per unit of GDP. It concludes that for a 50 % chance of limiting temperature rise to 2˚C, carbon intensity needs to fall by more than 5 % per year every year until 2050.
Over the last decade or so, carbon intensity has been falling by only 0.8 % per year. PwC concludes that, if decarbonisation rates do not improve, the world will not be able to meet its two degree target.
Note that Carbon Brief provides a very useful summary of the report, which you can find here.