Pricewaterhouse Coopers (PwC) have released a report that says that G20 countries need to cut carbon intensity levels by 35% by 2020 - four times the annual rate achieved in 2000-8 climate change. In addition, global emissions from energy use need to peak by around 2015, declining to 2009 levels by 2020. Looking forward to 2050 the report says that G20 governments have a huge challenge to achieve the required reductions in carbon intensity by 2050. It will require concerted efforts from all countries on all fronts, including energy efficiency, greater use of nuclear and renewables and, in the longer run, the broad deployment of carbon capture and storage.