Global greenhouse gas emissions could rise 50 percent by 2050 without more ambitious climate policies, as fossil fuels continue to dominate the energy mix, the Organization for Economic Cooperation and Development (OECD) said in its environment outlook to 2050. The global economy in 2050 will be four times larger than today and the world will use around 80 percent more energy. But the global energy mix is not predicted to be very different from that of today, the report said. Fossil fuels such as oil, coal and gas will make up 85 percent of energy sources. Renewables, including biofuels, are forecast to make up 10 percent and nuclear the rest.

Due to such dependence on fossils, carbon dioxide emissions from energy use are expected to grow by 70 percent, the OECD said, which will help drive up the global average temperature by 3 to 6 degrees Celsius by 2100 - exceeding the internationally agreed warming limit of within 2 degrees.